Food‐grade titanium dioxide (E171) by solid or liquid matrix administration induces inflammation,germ cells sloughing in seminiferous tubules and blood‐testis barrier disruption in mice

Food‐grade titanium dioxide labeled as E171 has been approved for human consumption by the Food and Drug Administration (USA) and by the European Union for five decades. However, titanium dioxide has been classified as a possible carcinogen for humans by the International Agency of Research in Cancer raising concerns of its oral intake and the translocation to bloodstream, which could disturb barriers such as the blood‐testis barrier. There is evidence that titanium dioxide by intragastric/intraperitoneal/intravenous administration induced alterations on testosterone levels, testicular function and architecture, but studies of the E171 effects on the testicle structure and blood‐testis barrier are limited. E171 is contained not only in foods in liquid matrix but also in solid ones, which can exert different biological effects. We aimed to compare the effects of E171 consumption in a solid matrix (0.1%, 0.5% and 1% in pellets) and liquid suspension (5 mg/kg body weight) on testis structure, inflammation infiltrate and blood‐testis barrier disruption of male BALB/c mice. Results showed that none of the administration routes had influence on body weight but an increase in germ cell sloughing and the infiltrate of inflammatory cells in seminiferous tubules, together with disruption of the blood‐testis barrier were similar in testis of both groups even if the dose received in mice in liquid matrix was 136 or 260 times lower than the dose reached by oral intake in solid E171 pellets in 0.5% E171 and 1% E171, respectively. This study highlights the attention on matrix food containing E171 and possible adverse effects on testis when E171 is consumed in a liquid matrix.     

Developmental neurotoxicity of organophosphorous pesticides: fetal and neonatal exposure to chlorpyrifos alters sex-specific behaviors at adulthood in mice.

Developmental exposure to the organophosphorous insecticide chlorpyrifos (CPF) induces long-term effects on brain and behavior in laboratory rodents. We evaluated in adult mice the behavioral effects of either fetal and/or neonatal CPF exposure at doses not inhibiting fetal and neonatal brain cholinesterase. CPF (3 or 6 mg/kg) was given by oral treatment to pregnant females on gestational days 15-18 and offspring were treated sc (1 or 3 mg/kg) on postnatal days (PNDs) 11-14. Serum and brain acetylcholinesterase (AChE) activity was evaluated at birth and 24 h from termination of postnatal treatments. On PND 70, male mice were assessed for spontaneous motor activity in an open-field test and in a socioagonistic encounter with an unfamiliar conspecific. Virgin females underwent a maternal induction test following presentation of foster pups. Both sexes were subjected to a plus-maze test to evaluate exploration and anxiety levels. Gestational and postnatal CPF exposure (higher doses) affected motor activity in the open field and enhanced synergically agonistic behavior. Postnatal CPF exposure increased maternal responsiveness toward pups in females. Mice of both sexes exposed to postnatal CPF showed reduced anxiety response in the plus-maze, an effect greater in females. Altogether, developmental exposure to CPF at doses that do not cause brain AChE inhibition induces long-term alterations in sex-specific behavior patterns of the mouse species. Late neonatal exposure on PNDs 11-14 was the most effective in causing behavioral changes. These findings support the hypothesis that developmental CPF may represent a risk factor for increased vulnerability to neurodevelopmental disorders in humans.     

The interactions of diet-induced obesity and organophosphate flame retardant exposure on energy homeostasis in adult male and female mice

ABSTRACT

Previously, sex-dependent alterations in energy homeostasis were reported in adult mice fed a standard chow attributed to exposure to a mixture of organophosphate flame retardants (OPFRs) via estrogen receptors (ERα). In this study, adult male and female mice (C57BL/6J; Taconic) were treated with the same mixture of OPFRs (1 mg/kg each of tricresyl phosphate (TCP), triphenyl phosphate (TPP), and tris(1-3-dichloro-2propyl)phosphate (TDCPP)) for 7 weeks on a low-fat diet (LFD, 10% kcal fat) or a high fat (HFD, 45% kcal fat) in a diet-induced obesity model. Consistent with our previous observations, OPFRs altered weight gain in males, differentially with diet, while females remained unaffected. OPFR treatment also revealed sex-dependent perturbations in metabolic activity. During the night (approximately 0100–0400 hr), males exhibited elevated activity and oxygen consumption, while in females these parameters were decreased, irrespective of diet. OPFR disrupted feeding behavior and abolished diurnal water intake patterns in females while increasing nighttime fluid consumption in males. Despite no marked effect of OPFRs on glucose or insulin tolerance, OPFR treatment altered circulating insulin and leptin in females and ghrelin in males. Data indicate that adult OPFR exposure might influence, and perhaps exacerbate, the effects of diet-induced obesity in adult mice by altering activity, ingestive behavior, and metabolism.     

Pubertal exposure to bisphenol A disrupts behavior in adult C57BL/6J mice

Bisphenol A (BPA) is a widespread endocrine disrupting chemical that influences adult physiology and behavior after perinatal exposure. However, it is not clear if pubertal exposure to BPA exerts hormone dependent effects on behaviors. Using C57BL/6J mice, we sought to determine how pubertal exposure to BPA affects locomotion, exploration, anxiety and sociability in adulthood. Compared to controls, pubertal exposure to BPA or E(2) (17β-estradiol) significantly altered female exploratory and anxiety behavior. Moreover, BPA and E(2)-treated female mice displayed increased levels of affiliation to female stimulus mice and decreased levels of affiliation to male stimulus mice; while our control males showed affiliation preference to female stimulus. These results indicate that pubertal exposure to BPA or E(2) may masculinize female social and emotional behavior.     

Behavioral effects induced by subchronic exposure to Pb and their reversion are concentration and gender dependent

Lead (Pb) seems to be involved in the etiology of psychological pathologies. This study investigated the effects of subchronic Pb exposure from weaning to adulthood on anxiety, depression and aggressiveness in male and female Swiss mice. Moreover, the reversibility of the effects was evaluated retesting the animals 30 days after the end of exposure. Swiss male and female mice (21 days) were exposed to 0, 50, 100 or 500 ppm of Pb, as Pb acetate, in drinking water for 70 days and were submitted to the forced swimming, tail suspension, elevated plus-maze or intruder-resident tests. Pb exposure to 50 and 500 ppm induced anti-depressant-like effect in both males and females, whereas exposure to 500 ppm induced anxiogenic effect only in males. Interruption of exposure was able to reverse the behavioral alterations in females, but not in males exposed to the highest concentration (500 ppm). Our results suggest that behavioral effects induced by subchronic exposure to Pb from weaning to adulthood and their reversion are concentration and gender dependent.     

Toxicology of 1,1,2-trichloroethane in the mouse

1,1,2-Trichloroethane (TCE) was administered to male and female CD-1 mice to evaluate its effect on standard toxicological parameters. Following determination of the acute LD50 (378 mg/kg in males and 491 mg/kg in females), and a 14-day range-finding study, a 90-day drinking water study was performed in which the doses consumed were 4.4, 46, and 305 mg/kg for males and 3.9, 44, and 384 mg/kg for females. The liver was a target of TCE toxicity in both sexes as demonstrated by dose-dependent alterations in hepatic microsomal enzyme activities and serum enzyme levels. The erythroid element of the female mice was also affected, as indicated by significantly decreased hematocrit and hemoglobin levels.     

Combined exposure to tobacco smoke and ethanol during adolescence leads to short- and long-term modulation of anxiety-like behavior

Background

Tobacco smoking is associated with alcohol drinking and consumption of both drugs typically begins during adolescence. Since anxiety is considered a relevant factor for both smoking and drinking due to its motivating force for a continued consumption, anxiety alterations shared by these two drugs could explain their co-use and co-abuse.

Methods

Here, we investigated the short- and long-term effects of adolescent tobacco smoke and/or ethanol exposure on anxiety levels. From postnatal day 30–45, Swiss mice were exposed to tobacco smoke (SMK – whole body exposure, 8 h/day) and/or ethanol (ETOH – 25% solution, 2 g/kg i.p. injected every other day) as follows: (1) SMK + ETOH exposure; (2) SMK exposure; (3) ETOH exposure; (4) Control. Anxiety levels were assessed with the elevated plus maze and open field tests.

Results

By the end of exposure, SMK female mice presented an anxiolytic response in the elevated plus maze and this response was intensified by co-exposure to ethanol. A short-term deprivation from SMK elicited an anxiogenic state in females in this maze. Although neither smoke nor ethanol effects persisted one month post-exposure, SMK + ETOH male and female mice exhibited an anxiogenic response in the open field.

Conclusion

Adolescent female mice are more susceptible to the anxiolytic effects of SMK. The stronger effect in SMK + ETOH group suggests that, in females, the combined exposure leads to lower anxiety levels. Anxiety levels do not seem to be relevant during a short-term SMK + ETOH deprivation, however, increased anxiety during long-term smoking and drinking deprivation demonstrate late-emergent effects both in males and females.     

Toxicology of 1,1,2-Trichloroethane in the Mouse

ABSTRACT

1,1,2-Trichloroethane (TCE) was administered to male and female CD-I mice to evaluate its effect on standard toxicologi-cal parameters. Following determination of the acute LD50 (378 mg/kg in males and 491 mg/kg in females), and a 14-day range-finding study, a 90-day drinking water study was performed in which the doses consumed were 4.4, 46, and 305 mg/kg for males and 3.9, 44, and 384 mg/kg for females. The liver was a target of TCE toxicity in both sexes as demonstrated by dose-dependent alterations in hepatic microsomal enzyme activities and serum enzyme levels. The erythroid element of the female mice was also affected, as indicated by significantly decreased hematocrit and hemoglobin levels.     

Subchronic toxicity of cyclohexane in rats and mice by inhalation exposure

Inhalation studies were conducted to determine the potential toxicity and/or potential neurotoxicity of cyclohexane. Groups of rats and mice were exposed to 0, 500, 2000, or 7000 ppm concentrations of cyclohexane vapor 6 hr/day, 5 days/week for 14 weeks. Subgroups of rats and mice were further observed during a 1-month recovery period. Functional observational battery (FOB) and motor activity (MA) behavioral tests were conducted on rats. These tests were conducted prior to the exposure series and during weeks 4, 8, and 13 on non-exposure days. Clinical pathology evaluations were conducted after approximately 7, 13, and 18 weeks. Approximately 14 and 18 weeks after study initiation, tissues from rats and mice were histologically processed and evaluated by light microscopy. During exposure to 2000 or 7000 ppm, rats and mice had a diminished response or an absent response to delivery of a punctate auditory alerting stimulus. Immediately following removal of rats from the inhalation chambers, 7000 ppm males and females and 2000 ppm females displayed a compound-related increase in the incidence of wet and/or stained fur (which occurred in the areas of the mouth, chin, and/or perineum). These signs were transient, were not observed during exposure or prior to exposure the following day, and were not associated with any behavioral or morphological changes. During exposure sessions, mice exposed to 7000 ppm exhibited clinical signs of toxicity which included hyperactivity, circling, jumping/hopping, excessive grooming, kicking of rear legs, standing on front legs, and occasional flipping behavior. Clinical signs of toxicity observed in 7000 ppm mice immediately after exposure included hyperactivity, hyperreactivity, ruffled fur (females only), gait abnormalities, spasms in both rear legs, and excessive grooming (males only). The clinical signs observed in mice during and immediately after exposure were transient, and were not present prior to the subsequent exposure. A few mice exposed to 2000 ppm appeared hyperactive during exposure in the latter portion of the study. There were no compound-related changes in mean body weights, body weight gains, food consumption, food efficiency, or mortality; and there were no ophthalmological abnormalities in rats or mice. In addition, there were no compound-related effects on 37 different behavioral parameters assessed during the FOB or during motor activity tests in rats. Male and female mice exposed to 7000 ppm had slight increases in measures of circulating erythrocyte mass (red blood cells, hemoglobin, hematocrit) and plasma protein concentration (males only). Male rats and male and female mice exposed to 7000 ppm had significantly increased relative liver weights, and 7000 ppm male mice also had significantly increased absolute liver weights at the end of the exposure period. At the end of the 1-month recovery period, absolute and relative liver weights of male and female mice were similar to control. However, relative liver weights of 7000 ppm male rats continued to be significantly higher at the end of the recovery period. Male and female rats exposed to 7000 ppm had a significantly increased incidence of hepatic centrilobular hypertrophy at the end of the exposure period, which was not observed at the conclusion of the 1-month recovery period. No microscopic changes were observed in mice. In rats, the no-observed-effect level (NOEL) for acute, transient effects was 500 ppm based on a diminished/absent response to an auditory alerting stimulus at 2000 ppm and above. The NOEL for subchronic toxicity in rats was 7000 ppm based on the lack of adverse effects on body weight, clinical chemistry, tissue morphology, and neurobehavioral parameters. In mice, the NOEL for acute, transient effects was 500 ppm based on behavioral changes during exposure at 2000 ppm and above. The NOEL for subchronic toxicity in mice is 2000 ppm based on hematological changes at 7000 ppm.     

Evaluation of 13-week inhalation toxicity of sec-butanethiol in rats

The subchronic toxicity of sec-butanethiol was investigated in Sprague-Dawley rats following a 13-week period of repeated inhalation exposure. Four groups of 10 rats of each sex were exposed to sec-butanethiol vapor by whole-body inhalation at 0, 25, 100, or 400 ppm for 6 h per day, 5 days a week over a 13-week period. At 400 ppm, both genders exhibited a decrease in food consumption, although a decrease in the body weight gain was only observed in females. Hematological investigations revealed a decrease in red blood cell, hemoglobin, and hematocrit in both the male and female groups, whilst the female group exhibited an increase in the mean corpuscular volume and a decrease in the mean corpuscular hemoglobin concentration. There was an increase in kidney weight for both genders but the liver weight was only higher in males than controls. Histopathological alterations were found in the kidneys, spleen, and nasal olfactory epithelium. There were no treatment-related effects observed in both genders at 100 ppm. Under the present experimental conditions, the target organs were determined to be the blood cells, the kidneys, the liver, and the nasal turbinates in rats. The no-observed-effect level was considered to be 100 ppm in rats.     

Influences of gender,development, pregnancy and ethanol consumption on the hematotoxicity of inhaled 10 ppm benzene

 The hematotoxic effects of benzene in both humans and animals are well documented. Current estimates concerning the risks associated with benzene exposure are usually based on adult, male cohort studies; however, there are indications that females may respond differently than males to benzene and that fetuses may respond differently than adults. Another factor to be considered in risk estimates is the impact of personal habits. In experimental animals, ethanol consumption is known to increase the hematotoxicity of benzene; therefore, alcohol consumption may also alter the potential risk of individuals exposed to benzene. To address some of the factors that may confound risk estimates for benzene exposure, a series of experiments were performed. Age-matched male as well as pregnant and virgin female Swiss Webster mice were exposed to 10 ppm benzene for 6 h a day over 10 consecutive days (days 6 through 15 of gestation for the pregnant females). Half of the animals also received 5% ethanol in the drinking water during this period. On day 11, bone marrow cells from the adults and liver cells from the fetuses were assayed for the numbers of erythroid colony-forming units (CFU-e). CFU-e assays were also performed on bone marrow cells isolated from 6-week postpartum dams exposed during gestation and from in utero-exposed 6-week old males and females. Gender differences were clearly observed in the responses to the various exposure protocols. Depressions in CFU-e numbers were only seen in male mice while elevations in CFU-e numbers were only seen in female mice. Male mice exposed as adults for 10 days to benzene (B), ethanol (E) or benzene+ethanol (B+E) exhibited depressed CFU-e levels as did male fetal mice exposed to B in utero. In addition, adult male mice which had been exposed in utero to either B or to E individually displayed depressed CFU-e levels. In contrast, none of the groups of female mice exhibited any depressions in CFU-e numbers after any of the exposures. Elevations in CFU-e numbers were observed among pregnant females exposed to E and among adult females exposed to B+E in utero. In summary, a majority (6/9) of the exposure protocols produced depressions in the CFU-e numbers of male mice, whereas a majority (7/9) of the exposure protocols produced no changes in the CFU-e numbers of female mice. Those changes that were observed in females consisted of elevations of CFU-e numbers. These results suggest that the male erythron is more susceptible than the female erythron to the hematotoxicants benzene and ethanol, regardless of whether exposures occur in utero or during adulthood. Received: 21 February 1995 / Accepted: 14 May 1995     

SUBCHRONIC TOXICITY OF CYCLOHEXANE IN RATS AND MICE BY INHALATION EXPOSURE

Inhalation studies were conducted to determine the potential toxicity and/or potential neurotoxicity of cyclohexane. Groups of rats and mice were exposed to 0, 500, 2000, or 7000 ppm concentrations of cyclohexane vapor 6 hr/day, 5 days/week for 14 weeks. Subgroups of rats and mice were further observed during a 1-month recovery period. Functional observational battery (FOB) and motor activity (MA) behavioral tests were conducted on rats. These tests were conducted prior to the exposure series and during weeks 4, 8, and 13 on non-exposure days. Clinical pathology evaluations were conducted after approximately 7, 13, and 18 weeks. Approximately 14 and 18 weeks after study initiation, tissues from rats and mice were histologically processed and evaluated by light microscopy.

During exposure to 2000 or 7000 ppm, rats and mice had a diminished response or an absent response to delivery of a punctate auditory alerting stimulus. Immediately following removal of rats from the inhalation chambers, 7000 ppm males and females and 2000 ppm females displayed a compound-related increase in the incidence of wet and/or stained fur (which occurred in the areas of the mouth, chin, and/or perineum). These signs were transient, were not observed during exposure or prior to exposure the following day, and were not associated with any behavioral or morphological changes. During exposure sessions, mice exposed to 7000 ppm exhibited clinical signs of toxicity which included hyperactivity, circling, jumping/hopping, excessive grooming, kicking of rear legs, standing on front legs, and occasional flipping behavior. Clinical signs of toxicity observed in 7000 ppm mice immediately after exposure included hyperactivity, hyperreactivity, ruffled fur (females only), gait abnormalities, spasms in both rear legs, and excessive grooming (males only). The clinical signs observed in mice during and immediately after exposure were transient, and were not present prior to the subsequent exposure. A few mice exposed to 2000 ppm appeared hyperactive during exposure in the latter portion of the study. There were no compound-related changes in mean body weights, body weight gains, food consumption, food efficiency, or mortality; and there were no ophthalmological abnormalities in rats or mice. In addition, there were no compound-related effects on 37 different behavioral parameters assessed during the FOB or during motor activity tests in rats.

Male and female mice exposed to 7000 ppm had slight increases in measures of circulating erythrocyte mass (red blood cells, hemoglobin, hematocrit) and plasma protein concentration (males only).

Male rats and male and female mice exposed to 7000 ppm had significantly increased relative liver weights, and 7000 ppm male mice also had significantly increased absolute liver weights at the end of the exposure period. At the end of the 1-month recovery period, absolute and relative liver weights of male and female mice were similar to control. However, relative liver weights of 7000 ppm male rats continued to be significantly higher at the end of the recovery period. Male and female rats exposed to 7000 ppm had a significantly increased incidence of hepatic centrilobular hypertrophy at the end of the exposure period, which was not observed at the conclusion of the 1-month recovery period. No microscopic changes were observed in mice.

In rats, the no-observed-effect level (NOEL) for acute, transient effects was 500 ppm based on a diminished/absent response to an auditory alerting stimulus at 2000 ppm and above. The NOEL for subchronic toxicity in rats was 7000 ppm based on the lack of adverse effects on body weight, clinical chemistry, tissue morphology, and neurobehavioral parameters. In mice, the NOEL for acute, transient effects was 500 ppm based on behavioral changes during exposure at 2000 ppm and above. The NOEL for subchronic toxicity in mice is 2000 ppm based on hematological changes at 7000 ppm.     

Sex differences in voluntary oral nicotine consumption by adolescent mice: a dose-response experiment

Recent studies with adolescent rodents offer valuable information regarding the neurochemical and behavioral effects of adolescent nicotine exposure. One hundred twenty-one male and 125 female adolescent (35 days of age) C57BL/6J mice were tested for voluntary nicotine consumption by providing 24-h access to both saccharin-only (SAC) and one of six nicotine-containing solutions [10, 25, 50, 75, 100, 200 ug (-)-freebase nicotine/ml in 2% SAC] in the home cage for 7 days. Although males and females drank similar volumes (ml) of nicotine, the female mice consumed more nicotine adjusted for body weight (mg/kg) and as a percentage of total fluid intake than did the male mice. In contrast, there was no sex difference in overall serum cotinine levels (adjusted for liver weight). For all mice, nicotine consumption and serum cotinine levels increased in a dose-dependent manner, and the volume of nicotine intake (ml), percent nicotine intake, and nicotine dosage (mg/kg) on the last day of the experiment were positively correlated with cotinine levels. Cotinine levels were inversely related to body weight only for females. Sex differences in nicotine consumption, but not in cotinine levels, suggest sex differences in pharmacokinetic processes that may contribute to oral nicotine consumption behavior during periadolescence.     

Repeated administration of the food additive E171 to mice results in accumulation in intestine and liver and promotes an inflammatory status

Abstract

Titanium dioxide (TiO₂) is widely used in pharmaceuticals preparations, cosmetics, and as a food additive (E171). It contains microparticles and a fraction of nanoparticles (NPs) which can be absorbed systemically by humans after ingestion. Increasing concern has been aroused about the impact of oral exposure to TiO₂ NPs from dietary and non-dietary sources on human health. In spite of several toxicological studies conducted in recent years, a solid risk assessment of oral exposure to E171 has not been satisfactorily achieved. We investigated whether repeated oral administration of E171 to mice at a dose level (5?mg/kg body weight for 3?days/week for 3?weeks) comparable to estimated human dietary exposure, results in TiO₂ deposition in the digestive system and internal organs, and in molecular and cellular alterations associated with an inflammatory response. To reproduce the first phase of digestion, a new administration approach involving the dripping of the E171 suspension into the mouth of mice was applied. Significant accumulation of titanium was observed in the liver and intestine of E171-fed mice; in the latter a threefold increase in the number of TiO₂ particles was also measured. Titanium accumulation in liver was associated with necroinflammatory foci containing tissue monocytes/macrophages. Three days after the last dose, increased superoxide production and inflammation were observed in the stomach and intestine. Overall, the present study indicates that the risk for human health associated with dietary exposure to E171 needs to be carefully considered.     

Neonatal exposure to chlorpyrifos affects maternal responses and maternal aggression of female mice in adulthood

CD-1 mice were exposed to the organophosphate pesticide chlorpyrifos (CPF) throughout postnatal days (PND) 11–14 at the subtoxic dose of 3 mg/kg. At adolescent age, females and males underwent a sociability test in which level of sociability and social preference were measured. At adulthood only females' behavior was analyzed. Maternal behavior of CPF-exposed females was assessed on postpartum day 1 after removal of the pups for 1 h, while anxiety levels were measured in a 5 min dark–light test on postpartum day 2. Nest defense response to an unfamiliar male intruder was assessed on postpartum day 7. In addition, from birth to postpartum day 7 a detailed analysis of nest building activity was carried out. Neonatal CPF exposure does not interfere with social behavior and social preferences at adolescence, whereas at adulthood it induces significant behavioral alterations in lactating females. Motivation to build and defend the nest was decreased in CPF females that were also less anxious than controls in the dark–light paradigm. These results confirm that developmental exposure to CPF induces long-lasting alterations in selected sexual-dimorphic responses of the adult social repertoire, and suggest that early exposure to CPF might interfere with hypothalamic neuroendocrine mechanisms regulating social responses.     

Effect of early pre- and postnatal acquired malnutrition on development and sexual behavior in the rat

In this paper we attempt to elucidate the effects on the rat offspring of undernourishment during pregnancy and lactation on the following parameters were examined: weight at birth and its evolution over a three-month period, sexual behavior of adult males, vaginal opening and sexual cycle of females, blood sugar, blood proteins, hematocrit, natremia, potassemia, body weight and weight of testicles, seminal vesicles and adrenal glands in males 5 months of age. Our results indicate highly significant decreases in body weight in experimental animals over a period of three months. Vaginal opening in experimental females is significantly delayed and their estrous cycle is shortened. Male sexual behavior shows decreases in neuromotor activity and prolongation of the refractory period in experimental male animals. Of the parameters monitored at 5 months of age, only blood sugar levels were significant decreased in experimental male rats. In view of these results, it can be concluded that in utero and lactation period malnutrition affects fundamental parameters of both development and reproductive function in the offspring.     

Intracranial cycloheximide: effect on male mouse sexual behavior and plasma testosterone.

Cycloheximide (Cyclo), an inhibitor of protein synthesis, infused bilaterally into the preoptic area (POA) of intact B6D2F male mice significantly inhibited male sexual behavior when the males were presented with receptive females 12 hr after treatment. The few males that ejaculated appeared to copulate normally. This finding suggests that Cyclo acts primarily by inhibiting sexual arousal rather than sexual performance. The inhibition of sexual behavior was not observed when the males were tested 84 hr after treatment. After exposure to an estrous female, plasma testosterone levels were measured in males with POA infusions of Cyclo or saline vehicle. No significant difference was found, but both groups had significantly higher levels of plasma testosterone than males not exposed to estrous females. It is suggested that the interference with sexual behavior by Cyclo was not due to interference with the neuroendocrine mechanisms controlling blood andorgen levels, but due to Cyclo acting directly on the neural circuits controlling sexual responsiveness.     

Hematological and Clinical Chemistry Changes Induced by Subchronic Dosing of a Novel Phosphorothionate (RPR-V) in Wistar Male and Female Rats

A novel phosphorothionate [2-butenoic acid-3-(diethoxy phosphinothioyl)-ethyl ester; RPR-V] synthesized at Indian Institute of Chemical Technology (Hyderabad, India) was studied using subchronic doses of 0.033 (low), 0.066 (medium), and 0.099 (high) mg kg^{? 1} in male and female rats daily for 90 days. Continuous treatment with RPR-V caused significant (p < 0.05) decreases in body-weight gain, feed intake, hemoglobin (Hb), hematocrit (Hct), and total erythrocyte count (TEC), whereas total leukocyte count (TLC), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), and mean corpuscular hemoglobin concentration (MCHC) were increased. Similarly, RPR-V caused significant elevation in serum clinical chemistry parameters calcium, phosphorus, creatinine, and chloride contents, whereas protein and glucose levels were depressed in both male and female treated rats after 45 and 90 days of treatment. These alterations were significant when compared with two-way ANOVA showing that these changes were dose- and time-dependent. The effects of low dose were generally not statistically significant, whereas medium and high doses caused significant effects. The changes in male rats were not significant when compared with female rats showing no sexual dimorphism by this compound. Recovery was observed after 28 days post-treatment (withdrawal study), indicating that the compound entered into the system was eliminated from the body, and the blood parameters were improved. Hematological and clinical chemistry parameters can be detected rapidly and hence can be used for prediction and diagnosis of pesticide toxicity. Alterations in these parameters show toxic stress in the treated animals especially on blood and blood-forming organs.     

Influence of olfactory bulbectomy and the serotonergic system upon intermale aggression and maternal behavior in the mouse

Biochemical parameters in the brains of olfactory bulbectomized male and female mice were studied in two experiments, followed by three experiments in which 5-HTP was injected into bulbectomized males and females to try to block abnormal behaviors. In Experiment 1 bulbectomized male and female mice had significantly less tryptophan hydroxylase in their brains than did sham controls. Neither 5-hydroxytrptophan decarboxylase nor tyrosine hydroxylase activity was affected. In Experiment 2 the rate of synthesis of 5-HT was significantly less in bulbectomized males and females. Since bulbectomy leads to increased pup killing by female mice, the objective of Experiments 3 and 4 was to see whether the injection of 5-HTP into bulbectomized females could block this behavior. The incidence of pup killing was not influenced, but in both studies the latency to kill was significantly prolonged. Olfactory bulbectomy eliminates aggressive behavior in male mice, and the purpose of Experiment 5 was to determine whether 5-HTP treatment could restore normal levels of aggression. No significant effect was found. The data suggest that a dual mechanism is needed to explain the behavioral abnormalities seen in the two sexes; the mechanism in the female appears to be serotonergic while that in the male is still unknown.     

Hematological and clinical chemistry changes induced by subchronic dosing of a novel phosphorothionate (RPR-V) in Wistar male and female rats

A novel phosphorothionate [2-butenoic acid-3-(diethoxy phosphinothioyl)-ethyl ester; RPR-V] synthesized at Indian Institute of Chemical Technology (Hyderabad, India) was studied using subchronic doses of 0.033 (low), 0.066 (medium), and 0.099 (high) mg kg(- 1) in male and female rats daily for 90 days. Continuous treatment with RPR-V caused significant (p < 0.05) decreases in body-weight gain, feed intake, hemoglobin (Hb), hematocrit (Hct), and total erythrocyte count (TEC), whereas total leukocyte count (TLC), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), and mean corpuscular hemoglobin concentration (MCHC) were increased. Similarly, RPR-V caused significant elevation in serum clinical chemistry parameters calcium, phosphorus, creatinine, and chloride contents, whereas protein and glucose levels were depressed in both male and female treated rats after 45 and 90 days of treatment. These alterations were significant when compared with two-way ANOVA showing that these changes were dose- and time-dependent. The effects of low dose were generally not statistically significant, whereas medium and high doses caused significant effects. The changes in male rats were not significant when compared with female rats showing no sexual dimorphism by this compound. Recovery was observed after 28 days post-treatment (withdrawal study), indicating that the compound entered into the system was eliminated from the body, and the blood parameters were improved. Hematological and clinical chemistry parameters can be detected rapidly and hence can be used for prediction and diagnosis of pesticide toxicity. Alterations in these parameters show toxic stress in the treated animals especially on blood and blood-forming organs.