Cocaine responsiveness or anhedonia in rats treated with methylphenidate during adolescence

Methylphenidate (MPH) treatment in boys diagnosed with ADHD is reported to decrease the risk of drug abuse in adulthood. Similarly, MPH treatment appears to decrease the cocaine preference of male rats during conditioned place preference (CPP) tests. However, the effects of MPH treatment on later drug use of girls/women or CPP in female rodents have not been fully examined, nor have a clinically-relevant MPH dose and/or administration route been thoroughly studied. Here, Sprague–Dawley rats (n = 34/sex/treatment) were treated orally 3×/day on postnatal days (PNDs) 29–50 with water or 3 mg MPH/kg, a dose producing serum levels within the human clinical range. CPP assessments to cocaine (10 mg/kg, ip) (PNDs 62–71) indicated MPH-treated rats were less active during pre- and postconditioning sessions (p < .04), but there were no significant MPH-related differences in conditioning strength. Baseline open field activity at PND 84 indicated that MPH-treated females were more active than same-sex controls (p < .05). A cocaine challenge (10 mg/kg, ip) elevated activity similarly in MPH-treated and controls of both sexes. As an anhedonia measure, saccharin solution intake on PNDs 87–90 indicated no significant MPH effects. Estrous cycle phase did not appear to affect cocaine response during CPP or open field assessments. Hormonal levels at PND 90 indicated 63% higher corticosterone levels in MPH-treated females relative to same-sex controls (p < .05), a finding that deserves further investigation. These results address some of the major issues surrounding animal models of MPH treatment and provide additional support for a lack of severe long-term behavioral effects of adolescent MPH.     

Safety profile of Hoodia gordonii extract: Rabbit prenatal developmental toxicity study

Hoodia gordonii extract was orally administered by gavage to groups of 22 female New Zealand white rabbits from day 3–28 after mating at doses of 0 (control), 3, 6 or 12 mg/kg bodyweight/day. These doses were reached by a dose escalation phase between days 3 and 7 after mating. As well as a vehicle control group, a control group pair-fed to the high dose was also included. On day 29 after mating the females were euthanized and examined. Treatment at 6 or 12 mg/kg/day was associated with a dose-related reduction in feed intake and bodyweight gain. Feed consumption and bodyweight gain was unaffected at 3 mg/kg/day. In spite of marked maternal effects at 12 mg/kg/day, reproductive indices were unaffected at all doses and there were no effects on fetal or placental weights and no morphological changes in the fetuses. The no-observed-effect level (NOEL) for developmental effects was therefore 12 mg/kg/day, and the maternal NOEL was 3 mg/kg/day. At doses that caused marked maternal effects, H. gordonii extract did not affect embryonic or fetal development in a species that is considered predictive of developmental toxicity in man.     

Combined treatment with low dose prednisone and escin improves the anti-arthritic effect in experimental arthritis

The present study was aimed at investigating whether low dose oral prednisone combined with escin could inhibit the progression of adjuvant-induced arthritis (AIA) in rats. Adjuvant arthritis was induced in SD rats began day 1 for 28 days. Prednisone at doses of 2, 10 mg/kg/day alone or escin at doses of 5, 10 mg/kg/day alone, or prednisone at dose of 2 mg/kg/day with escin at doses of 5 or 10 mg/kg/day were given to different groups of rats intragastrically from day 13 to 28 respectively. Paw swelling, arthritic index, histological and radiographic changes were assessed to evaluate the anti-arthritic effect. Weight growth, spleen and thymus indexes were also calculated. Serum samples were collected for estimation of pro-inflammatory cytokines. Rats developed erosive arthritis of the hind paw when immunized with adjuvant. Prednisone 2 mg/kg combined with escin 5 or 10 mg/kg significantly inhibited the paw swelling. Histopathological and radiographic analysis showed a marked decrease of synovial inflammatory infiltration, synovial hyperplasia and bone erosion by combination therapy, which also markedly suppressed the expression of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6). No significant changes were found in monotherapy group except prednisone 10 mg/kg group. Furthermore, combined treatment rescued some of GCs' adverse effects evidenced by increase in body weight and decrease in index of spleen compared with untreated AIA rats. In conclusion, the combination therapy possessed synergistic anti-arthritic efficacy and reduced adverse effect, which may play a role in the management of human RA.     

An antioxidant,N,N′-diphenyl-p-phenylenediamine (DPPD), affects labor and delivery in rats: A 28-day repeated dose test and reproduction/developmental toxicity test

A 28-day repeated dose toxicity test and reproduction/developmental toxicity test for N,N′-diphenyl-p-phenylenediamine (DPPD) were conducted in [Crl:CD(SD)] SPF rats. Male and female rats were dosed with DPPD by gavage for 28 days at 0, 100, 300, or 1000 mg/kg bw/day or for a total of 42–46 days at 0, 8, 50, or 300 mg/kg bw/day. No significant adverse effects were observed in the repeated dose toxicity study up to 1000 mg/kg bw/day in both sexes. In the reproduction/developmental toxicity study, two females showed piloerection, hypothermia, and pale skin; one died and the other showed dystocia on day 23 of pregnancy at 300 mg/kg bw/day. Another female delivered only three live pups at 300 mg/kg bw/day. A significantly prolonged gestation period was observed at 50 and 300 mg/kg bw/day. The NOAELs of repeated dose toxicity and reproduction/developmental toxicity were considered to be 1000 and 8 mg/kg bw/day, respectively.     

Single and 90-day repeated oral dose toxicity studies of fermented Rhus verniciflua stem bark extract in Sprague–Dawley rats

Fermented Rhus verniciflua stem bark (FRVSB) extract, an urushiol-free extract of Rhus verniciflua Stokes (RVS) fermented with Fomitella fraxinea, has various biological activities. The present study was carried out to investigate the potential toxicity of the FRVSB extract following single and repeated oral administration to Sprague–Dawley rats. In the single dose toxicity study, the FRVSB extract was administered orally to male and female rats at single doses of 0, 2500, 5000, and 10,000 mg/kg. No animals died and no toxic changes were observed in clinical signs, body weight, and necropsy findings during the 15-day period following administration. In the repeated dose toxicity study, the FRVSB extract was administered orally to male and female rats for 90 days at doses of 0, 556, 1667, and 5000 mg/kg/day. There were no treatment-related adverse effects in clinical signs, body weight, food and water consumption, ophthalmic examination, urinalysis, hematology, serum biochemistry, necropsy findings, organ weight, and histopathology at any dose tested. The approximate lethal dose of the FRVSB extract was >10,000 mg/kg in both genders, the oral no-observed-adverse-effect level of the FRVSB extract was >5000 mg/kg/day in both genders, and no target organs were identified.     

Safety profile of Hoodia gordonii extract: Mouse prenatal developmental toxicity study

Hoodia gordonii extract (0, 5, 15 or 50 mg/kg body weight/day, n = 24 mice/group) was orally administered by gavage to female CD-1 mice from gestation days 5–17. On gestation day 18 the females were euthanized and examined. Treatment at 50 mg/kg/day caused a marked reduction in feed intake and body weight gain. Feed consumption was sporadically reduced at 15 mg/kg/day. At 50 or 15 mg/kg/day fetal weights, ossification of some bones and full and empty uterus weights were reduced. There were no clear maternal or fetal effects at 5 mg/kg/day. Reproductive indices were unaffected at all doses and there were no treatment-related malformations, anomalies or variations. The overall study no-observed-adverse-effect level was set at 5 mg/kg/day.In summary, at doses that reduced maternal feed consumption, H. gordonii extract delayed fetal development. The fetal effects seen could be consequent to reduced maternal feed consumption, the desired biological activity of the test item.     

Reproductive and developmental toxicity screening test of 3-cyanopyridine in rats

Crl:CD(SD)rats were given 3-cyanopyridine by gavage at 0, 5, 30 or 180 mg/kg/day. Males were dosed for 42 days beginning 14 days before mating, and females for 40–53 days beginning 14 days before mating to day 3 of lactation, including throughout the mating and gestation periods. General toxicity, mainly liver damage, was observed in males at ≥30 mg/kg/day and in females at ≥5 mg/kg/day. Sertoli cell vacuolation was observed at 180 mg/kg/day, and spermatocyte damages were observed at ≥30 mg/kg/day. Effects on estrous cycles, corpora lutea and implantations, and unsuccessfully mated females, despite additional mating, were observed at 180 mg/kg/day. Delayed initiation of delivery, dystocia, and deaths or moribundities of pregnant females were observed at 180 mg/kg/day, and only two pregnant rats delivered live pups at that dose. The NOAEL for reproductive/developmental toxicity was concluded to be 30 mg/kg/day.     

Disposition of diiosononyl phthalate and its effects on sexual development of the male fetus following repeated dosing in pregnant rats

Pregnant Sprague-Dawley rats received 50, 250, and 500 mg/kg/day diisononyl phthalate (DiNP) from GD 12 to 19 via corn oil gavage to study the dose response for effects on fetal male rat sexual development as well as metabolite disposition in the dam and fetus. Monoisononyl phthalate (MiNP), mono(carboxy-isooctyl) phthalate (MCiOP), mono(hydroxyl-isononyl) phthalate (MHiNP), mono(oxo-isononyl) phthalate (MOiNP), and monoisononyl phthalate glucuronide (MiNP-G) were found in all measured tissues. MCiOP was the major metabolite, followed in decreasing order by MiNP, MHiNP, MOiNP, and MiNP-G. Percentage of dose absorbed decreased at 750 mg/kg/day. Testosterone concentration in the fetal testes was reduced at 250 and 750 mg/kg/day. Multinucleated germ cells were increased in the testes of rats at 250 and 750 mg/kg/day. The no observed effect level (NOEL) for this study was 50 mg/kg/day based on increased MNGs and reduced testes testosterone concentration in the fetal rat.     

Impact of postnatal dexamethasone on psychotomimetic effects of MK-801 measured on adult rats

The present study investigates the impact of dexamethasone (DEX) given in tapering doses in the postnatal period on MK-801-induced locomotor activity and MK-801-evoked deficits of sensorimotor gating of adult rats (60 days old). It has been found that DEX given on postnatal day 1 (0.5 μg/g), day 2 (0.3 μg/g) and day 3 (0.1 μg/g) has no effects on spontaneous locomotor activity and does not influence locomotion observed after MK-801 given in a dose of 0.2 and 0.4 mg/kg. Postnatal DEX treatment did not alter the efficacy of sensorimotor gating and its deficits evoked by MK-801 at a dose of 0.2 and 0.4 mg/kg. However, a slight increase in the amplitude of startle reaction has been noted in DEX-treated animals. In conclusion, the results of the present study indicate that DEX given postnatally in tapering doses, although pharmacologically effective (decrease in a gain of body and brain weight), has no potential pro-psychotic effects and does not influence pharmacologically induced psychoses by MK-801. The above data indicate that apart from other side effects, the therapeutic application of DEX in the postnatal period is possibly safe in terms of the risk for developing schizophrenia.     

Effect of styrene exposure on plasma parameters,molecular mechanisms and gene expression in rat model islet cells

Styrene is an aromatic hydrocarbon compound present in the environment and have primary exposure through plastic industry. The current study was designed to evaluate styrene-induced toxicity parameters in rat plasma fasting blood glucose (FBG) level, oral glucose tolerance, insulin secretion, oxidative stress, and inflammatory cytokines in cellular and molecular levels. Styrene was dissolved in corn oil and administered at different doses (250, 500, 1000, 1500, 2000 mg/kg/day and control) to each rat, for 42 days. In treated groups, styrene significantly increased fasting blood glucose, plasma insulin (p < 0.001) and glucose tolerance. Glucose tolerance, insulin resistance and hyperglycemia were found to be the main consequences correlating gene expression of islet cells. Styrene caused a significant enhancement of oxidative stress markers (p < 0.001) and inflammatory cytokines in a dose and concentration-dependent manner in plasma (p < 0.001). Moreover, the activities of caspase-3 and −9 of the islet cells were significantly up-regulated by this compound at 1500 and 2000 mg/kg/day styrene administrated groups (p < 0.001). The relative fold change of GLUD1 was downregulated (p < 0.05) and upregulated at 1500 and 2000 mg/kg, respectively (p < 0.01). The relative fold changes of GLUT2 were down regulated at 250 and 1000 mg/kg and up regulated in 500, 1500 and 2000 mg/kg doses of styrene (p < 0.01). The expression level of GCK indicated a significant upregulation at 250 mg/kg and downregulation of relative fold changes in the remaining doses of styrene, except for no change at 2000 mg/kg of styrene for GCK. Targeting genes (GLUD1, GLUT2 and GCK) of the pancreatic islet cells in styrene exposed groups, disrupted gluconeogenesis, glycogenolysis pathways and insulin secretory functions. The present study illustrated that fasting blood glucose, insulin pathway, oxidative balance, inflammatory cytokines, cell viability and responsible genes of glucose metabolism are susceptible to styrene, which consequently lead to other abnormalities in various organs.     

Monitoring plasma voriconazole levels following intravenous administration in critically ill patients: an observational study

Data relating to the pharmacokinetics of voriconazole in critically ill patients are lacking. A prospective observational study was conducted on 18 non-consecutive critically ill patients aged 24–97 years, comprising 12 patients with normal renal function (NRF) [creatinine clearance (CL_Cr) ≥60 mL/min] and 6 patients with moderate renal impairment (MRI) (CL_Cr 40–55 mL/min), administered voriconazole intravenously (6 mg/kg loading dose and 3–4 mg/kg twice daily thereafter) in order to determine the suitability of these doses in this patient population. Steady-state blood levels were monitored and liver and renal function were recorded throughout treatment. Large variability in patient plasma levels was observed, ranging from 37% at ≤1 mg/L (minimum inhibitory concentration at which, for most fungal pathogens, 90% of isolates are susceptible) to 19% at >5.5 mg/L. Moreover, maintaining trough concentrations above clinical breakpoints was not consistently achieved because 16/30 (53%) were ≤1 mg/L. In a few MRI patients, average concentrations were found to be significantly different compared with those of NRF patients administered the same dose, however this difference was not noted in pharmacokinetic parameters following dose normalisation. None of the patients experienced deterioration in renal or liver function. Recommended voriconazole doses are inadequate to achieve drug concentrations >1 μg/mL over the entire dosing interval in some critically ill patients.     

Developmental toxicity assessment of the new turf herbicide,methiozolin ([5-(2,6-difluorobenzyl)oxymethyl-5-methyl-3,3(3-methylthiophen-2-yl)-1,2-isoxazoline]), in rabbits

Methiozolin is a new herbicide to control annual bluegrass (Poa annua L.) and large crabgrass (Digitaria sanguinalis (L.) Scop.) in various turfgrasses. The potential of methiozolin to induce maternal and developmental toxicity was investigated in the pregnant New Zealand White Rabbits. Methiozolin was, at dose levels of 0, 125, 250 and 500 mg/kg/day, administered by oral gavage to artificially inseminated rabbits (25 females per group) from days 6 to 28 of gestation. All does were subjected to Cesarean section on day 29 of gestation. At 500 mg/kg/day, treatment-related toxicities including abortion (10/22), decreased mean body weight, weight gain, net body weight change, reduced food consumption and decreased fetal weight were observed. At 125 and 250 mg/kg/day, no signs of maternal and developmental toxicity were observed. There were no treatment-related external, visceral and skeletal abnormalities of fetuses at all doses tested. In the current experimental conditions, the no observed adverse effect levels (NOAELs) of methiozolin are considered to be 250 mg/kg/day for does and prenatal development.     

Pharmacokinetics,pharmacodynamics and toxicity of a combination of metoprolol succinate and telmisartan in Wistar albino rats: Safety profiling

Metoprolol succinate (MET), a cardioselective β blocker and telmisartan (TEL), an angiotensin receptor blocker were administered orally, both individually and in combination to Wistar albino rats for evaluation of their pharmacokinetics, pharmacodynamics and repeated dose oral toxicity (28 days). Pharmacokinetic study was performed by analyzing drug concentration in plasma by a developed and validated LC–MS/MS method following oral administration of MET and TEL at 2.5 mg/kg and 2.0 mg/kg dose, respectively, both individually and in combination. Antihypertensive activity of MET and TEL in above dose and manner was evaluated on artificially induced hypertension on laboratory animals. In repeated dose oral toxicity study, MET (60, 120 and 240 mg/kg/day) and/or TEL (12, 24 and 48 mg/kg/day) were administered to animals for 28 days followed by a recovery period of 14 days. Pharmacokinetic data revealed the probable absence of any pharmacokinetic interaction when co-administered. Improved blood pressure lowering effect was observed by combination therapy. Moreover, toxic effects obtained at high dose level of each treatment groups were transient and reversible and no evidence of additive toxic effects were observed due to concomitant administration. So, this combination can primarily be stated as safe which will be confirmed after clinical interaction studies in humans.     

Pharmaco-EEG-based assessment of the interaction between ethanol and oxcarbazepine

Oxcarbazepine is a representative molecule for a new class of anticonvulsant drugs that can treat alcohol dependence in addition to other disorders. Interestingly, the central mechanism of action in oxcarbazepine is very similar to ethanol, suggesting that these two agents may interact and cause enhanced effects in the central nervous system. In this study, we used a pharmaco-EEG method to examine the influence of oxcarbazepine on the effect of ethanol on the EEG of rabbits (midbrain reticular formation, hippocampus, frontal cortex). Oxcarbazepine was administered po as a single dose (20 mg/kg or 80 mg/kg) or repeatedly at a dose of 40 mg/kg/day for 14 days. Ethanol was injected iv at a dose of 0.8 g/kg 60 min after the administration of oxcarbazepine. Ethanol caused an increase in the low frequencies (0.5–4 Hz) in the recordings, and it caused a marked decrease in higher frequencies (13–30 Hz and 30–45 Hz). Oxcarbazepine altered the EEG pattern in rabbits; this interaction was dependent on the dose of the drug and whether it was administered as a single dose or as multiple doses. Oxcarbazepine administered at a lower dose had a synergistic effect with ethanol in the frontal cortex and midbrain reticular formation, and a similar effect was observed in the hippocampus at a higher dose. Changes in EEG recordings after the administration of oxcarbazepine alone were more pronounced after multiple administrations. The drug decreased the sensitivity of the hippocampus to ethanol, an observation that may be important for the treatment of alcohol addiction.     

The effects of acute pharmacological stimulation of the 5-HT,NA and DA systems on the cognitive judgement bias of rats in the ambiguous-cue interpretation paradigm

In the present study, we investigated the effects of acute pharmacological stimulation of the serotonergic (5-HT), noradrenergic (NA) and dopaminergic (DA) systems on the valence of cognitive judgement bias of rats in the ambiguous-cue interpretation (ACI) paradigm. To accomplish this goal, after initial behavioural training, different groups of rats received single injections of citalopram, desipramine or d-amphetamine and were subsequently tested with the ACI paradigm. Each drug was administered in 3 doses using a fully randomised Latin square design. Citalopram at the dose of 1 mg/kg significantly biased animals towards positive interpretation of the ambiguous cue, while at higher doses (5 and 10 mg/kg), the animals interpreted the ambiguous cue more negatively. Desipramine at all 3 tested doses (1, 2 and 5 mg/kg) significantly biased animals towards negative interpretation of the ambiguous cue, while d-amphetamine at the dose of 1 mg/kg induced positive bias, having no effects at lower doses (0.1 and 0.5 mg/kg). Our results indicate that cognitive bias in rats can be influenced by acute pharmacological intervention.     

Acute and sub-chronic toxicity studies of the extract of Thunberg Fritillary Bulb

The aim of this study was to investigate the acute and sub-chronic toxicity of extract of Thunberg Fritillary Bulb. For the acute toxicity tests, graded doses of the extract were administered orally to mice. The animals were observed for toxic symptoms and mortality daily for 14 days. In the sub-chronic toxicity study, rats were orally administered the extract at doses of 1 and 3 mg/kg body weight (BW) for 26 weeks. After 26 weeks, the rats were sacrificed for hematological, biochemical and histological examination. In the acute toxicity tests, the estimated median lethal dosage (LD₅₀) was 52.2 mg/kg body weight in the mice. In the sub-chronic toxicity tests, a dose of 1 mg/kg body weight presented no toxicity. Above the 1 mg/kg dose, the main adverse signs observed in male rats were body or head tremor and spontaneous motor activity reduction. There were no other significant changes observed in hematology, blood biochemistry, organ weight and organ histology. The overall findings of this study indicate that the extract of Thunberg Fritillary Bulb is non-toxic up to 1 mg/kg body weight, which can be considered a safe application dose.     

Methoxychlor induced biochemical alterations and disruption of spermatogenesis in adult rats

Adult male albino rats were treated orally with methoxychlor at doses of 0, 50, 100 or 200 mg/kg/day for 15 consecutive days. Testicular weight, sperm count and motility were significantly decreased. Methoxychlor at doses of 100 and 200 mg/kg significantly inhibited α-glucosidase activity, while plasma testosterone was significantly decrease by the three dose levels in a dose-related pattern. Testicular activities of 3β-HSD, 17β-HSD, SDH were significantly decreased, while ACP, ALP (except for 50 mg/kg), and LDH were significantly increased. H₂O₂ production and LPO were significantly increased while the enzymic (SOD, CAT and GPx) and non-enzymic antioxidants (thiol content) were significantly decreased. Caspase-3 activity was significantly increased in a dose related manner. The findings of this study indicate that methoxychlor induces oxidative stress associated with impairment of spermatogenesis, in addition to apoptosis. These data provide insight into the mode of action of methoxychlor-induced toxicity in the rat testis.     

Activity of aminocandin (IP960; HMR3270) compared with amphotericin B,itraconazole, caspofungin and micafungin in neutropenic murine models of disseminated infection caused by itraconazole-susceptible and -resistant strains of Aspergillus fumigatus

Aminocandin (IP960; HMR3270; NXL201) is a new echinocandin with broad-spectrum in vitro activity against Aspergillus and Candida spp. We compared the activity of aminocandin with that of amphotericin B (AmB), itraconazole (ITC) and caspofungin (CAS) in murine models of disseminated aspergillosis against three strains of A. fumigatus, two of which were fully susceptible (AF293 and A1163) and one was resistant to ITC (AF91). Mice were rendered temporarily neutropenic or persistently neutropenic with cyclophosphamide and were infected intravenously 3 days later. Temporarily neutropenic mice were treated with either intraperitoneal (i.p.) AmB (5 mg/kg/dose), oral (p.o.) ITC (25 mg/kg/dose), intravenous (i.v.) aminocandin (0.25–10 mg/kg/dose), i.p. aminocandin (1 mg/kg/dose) or solvent control for 9 days. Mice were euthanised 11 days post infection and the kidneys and liver were removed for quantitative culture. Following infection with AF293, only aminocandin 5 mg/kg i.v. yielded 100% survival. Aminocandin 1 mg/kg i.v., AmB 5 mg/kg i.p. or ITC 25 mg/kg p.o. were equivalent (P > 0.05). Aminocandin 5 mg/kg was superior to aminocandin 0.25 mg/kg (P < 0.0001) as well as all controls (P < 0.0001) in reducing mortality. Following infection with AF91, only aminocandin at 5 mg/kg and 1 mg/kg i.v. yielded 100% survival, which was superior to ITC, aminocandin 0.25 mg/kg and controls (all P < 0.0001). In the persistently neutropenic model with A1163, aminocandin, CAS and micafungin (2–10 mg/kg) were all effective at prolonging survival, with some impact on reducing culture burdens, even with alternate-day dosing (4 mg/kg). The only fungicidal regimen was aminocandin 5 mg/kg, which sterilised 40% and 50% of mice following infection with AF293 and AF91, respectively. Aminocandin at doses of ≥1 mg/kg is highly effective in reducing mortality and organ burden in disseminated infection caused by ITC-susceptible and -resistant A. fumigatus.     

Combination of peramivir and rimantadine demonstrate synergistic antiviral effects in sub-lethal influenza A (H3N2) virus mouse model

Efficacy of combination of the intramuscularly administered neuraminidase (NA) inhibitor, peramivir, and the orally administered M2 ion channel blocker, rimantadine was evaluated in mouse influenza A/Victoria/3/75 (H3N2) model. Mice were challenged with a sub-lethal virus dose (0–40% mortality in placebo group) and changes in body weights were analyzed by three-dimensional effect analysis to assess mode of drug interactions.Compounds were administered in a 5-day treatment course starting 1 h before viral inoculation. The peramivir and rimantadine doses ranged from 0.3–3 mg/kg/d and 5–30 mg/kg/d, respectively. The maximum mean weight loss of 5.19 g was observed in the vehicle-infected group on day 10. In the 1 and 3 mg/kg/d peramivir monotherapy groups, the weight losses were 4.3 and 3.55 g, respectively. In the rimantadine monotherapy group, the weight losses were 3.43, 2.1, and 1.64 g for the 5, 10, and 30 mg/kg/d groups, respectively. Combination of 1 mg/kg/d peramivir with 5 and 10 mg/kg/d rimantadine produced weight losses of 1.69 and 0.69 (p < 0.05 vs. vehicle and individual agent), respectively, whereas the combination of 3.0 mg/kg/d peramivir with 10 and 30 mg/kg/d rimantadine did not show any weight loss (p < 0.05 vs. vehicle and individual agent). The three-dimensional analysis of the weight loss for the majority of the drug combinations of peramivir and rimantadine tested demonstrated synergistic antiviral effects.     

Preweaning behaviors,developmental landmarks,and acrylamide and glycidamide levels after pre- and postnatal acrylamide treatment in rats

At high levels of exposure, acrylamide monomer (AA) is a known neurotoxicant (LoPachin, 2004 [23]). The effects of lower levels of exposure, such as those experienced via a typical human diet, have not been widely investigated. Data at these levels are particularly relevant given the widespread human exposure through carbohydrate-containing foods cooked at high temperatures. Additionally, daily AA intake is estimated to be higher for infants and children. Earlier, we described behavioral alterations in preweaning rats resulting from developmental AA treatment (0.5–10.0 mg/kg/day) (Garey et al., 2005 [14]). In the present study, the effects of lower doses were measured as well as serum AA and glycidimide (GA) levels in dams, fetuses, and young pups. Pregnant Fischer 344 dams (n = 48–58/treatment group) were gavaged with 0.0, 0.1, 0.3, 1.0, or 5.0 mg AA/kg/day beginning on gestational day 6 and ending on the day of parturition. Beginning on postnatal day 1 (PND 1) and continuing through PND 21, all pups/litter were gavaged with the same dose as their dam. There were no AA treatment effects on offspring fur development, pinnae detachment, or eye opening. Offspring body weight was somewhat decreased by 5.0 mg/kg/day, particularly in males. However, righting reflex (PNDs 4–7), slant board (i.e., negative geotaxis) (PNDs 8–10), forelimb hang (PNDs 12–16), and rotarod behavior (PNDs 21–22) were not significantly altered by AA treatment. Male and female offspring of the 5.0 mg/kg/day group were 30–49% less active in the open field at PNDs 19–20 (p < 0.05). Serum AA levels of GD20 dams and their fetuses were comparable, indicating the ability of AA to cross the placental barrier. AA levels of pups were not affected by age (PND 1 and 22) or sex. In all rats, serum AA and GA levels exhibited a dose–response relationship. These data extend those of our previous study (Garey et al., 2005 [14]) and demonstrate that overt preweaning neurobehavioral effects are apparent in rats exposed to acrylamide pre- and postnatally, but only at the highest doses tested.