Prenatal ACTH and corticosterone: effects on reproduction in male mice

Injections of ACTH or corticosterone into late pregnant mice from Days 14 to 21 did not alter testes weights or feminine copulatory behavior of male offspring in adulthood. However masculine copulatory behavior was significantly reduced. Because ACTH does not cross the placenta, alterations in sexual behavior of male offspring were probably mediated by maternal corticosteroid secretion.     

Effects of prenatal stress on motor performance and anxiety behavior in Swiss mice

Stressor presence during the last weeks of gestation has been associated with behavioral disorders in later life. In this study we support further research on the long term effects of prenatal stress on Swiss mice descendant's behavior. Prenatal stress procedure consisted on restraining the dams under bright light for 45 min, three times per day from the 15th day of pregnancy, until birth. After weaning, offspring's motor performance and spontaneous exploratory behavior were measured by the tight-rope and T-maze tests, respectively. We also evaluated anxiety behavior using elevated plus maze test. We found that maternal stress improves the performance of the animals in the tight rope test and that this effect was sex and age dependent: prenatal stressed males obtained the best scores during the first month of life, while in females the same was achieved at the second month. Spontaneous exploratory behavior analysis revealed that it was elevated in prenatal stressed males and that this effect persisted on time. However, we did not find significant differences on this behavioral response among both females groups. Finally, differences on anxiety behavior were found only in females: prenatally stressed animals showed a higher proportion of entries into the open arms of a plus maze (reduced anxiety) compared to the control group. Our results show that prenatal stress modifies the normal behavior of the progeny: prenatal stressed animals have a better performance in the carried out test. These notably results suggest the existence of an adaptive response to prenatal stress.     

Effects of prenatal stress on sexual partner preference in mice

Three-month old, male Swiss Webster mice were born to either control dams or dams who had been prenatally stressed with light, heat, noise and handling during the last week of gestation. As adults, male offspring were tested on sexual partner preference and sexual behavior (mounting, intromissions and lordosis) with a sexually experienced male stimulus animal and a stimulus estrous female. In comparison to males born to control dams, prenatally stressed males showed a sexual partner preference for the sexually active male as demonstrated by a negative partner preference score, more and longer visits to the male's compartment, fewer and shorter visits to the female's compartment and longer latencies to and lower frequencies of mounts and intromissions of females. In addition, stressed males showed a greater frequency of lordosis and a higher lordosis quotient than did control males. This study is the first to investigate the effects of prenatal stress alone, without hormonal manipulation, on sexual partner preference using both a partner preference paradigm and measures of sexual behavior such as mounting, intromissions and lordosis. These findings support the suggestion that prenatal stress alone is enough to significantly affect sexual partner preference in male mice.     

Effects of male odor during infancy on the maturation, behavior, and reproduction of female mice

Infant female mice who were exposed to the odor of adult male mice of the same strain in the presence or absence of the mother were compared with mice who were not exposed with respect to maturation, open-field behavior, and reproductive success. Exposure lasted 4 hr daily during days 4–18 post-partum. No significant differences were found between the groups in their rates of growth or the age of ear, eye, and vaginal opening. However, the exposed groups displayed first estrus significantly earlier than non-exposed groups: the group exposed in the presence of the mothers showing the earliest first estrus of all 4 groups.     

不同光照制对雄性小鼠生殖影响的研究

目的 探讨不同光照制对雄性小鼠生殖的影响。方法 取昆明种雄性小鼠作短期持续光照、持续黑暗、反相光照3种光照制处理。观察小鼠睾丸、附睾重量及光镜下睾丸、附睾组织学变化、精子数量、精子活动度、精子畸形率。结果 各组小鼠睾丸、附睾重量无显著性差异,而且各实验组光镜下睾丸、附睾组织学均未见异常。与对照组相比,黑暗小鼠和反相光照组小鼠精子数量明显降低,此外,反相光照组小鼠精子畸形率显著增加。结论 异常光照周期可能影响雄性小鼠生殖能力。     

Variation in infanticide and parental behavior in male mice due to prior intrauterine proximity to female fetuses: Elimination by prenatal stress

When sexually-naive male mice are placed together with newborn young, some males will commit infanticide (kill the young) while others will behave parentally (retrieve the young to a nest and keep them warm). The intrauterine position of male mouse fetuses, which is recorded at Cesarean delivery, has previously been found to influence the titers of estradiol that male fetuses are exposed to in utero. In adulthood, most male mice that developed in utero between male fetuses (2 M males) behaved parentally toward young, while most males that developed in utero between female fetuses (0 M males) committed infanticide. When 0 M and 2 M males were castrated at birth and tested with young in adulthood, few males committed infanticide. But, when these same males were tested with young after 25 days of treatment with testosterone, more 0 M than 2 M males committed infanticide and more 2 M than 0 M males behaved parentally. In contrast to the above findings, more 2 M than 0 M males that were castrated when 28 days old behaved parentally without treatment with testosterone; few of the non-parental males committed infanticide, but, instead, ignored the young. Finally, stressing pregnant mice by placing them under bright lights during the last third of pregnancy eliminated the effect of developing next to female fetuses in the male offspring, and all prenatally-stressed males resembled 2 M males in their behavior toward young: most prenatally-stressed males were parental rather than infanticidal when tested with young. The significance of these findings to models of hormonal effects on sexual differentiation is discussed.     

Effects of prenatal stress on avoidance acquisition, open-field performance and lordotic behavior in male rats.

Prenatal stress enhanced lordotic behavior potentials in male rats but did not feminize patterns of active avoidance acquisition or open-field performance. These results suggest that prenatal stress selectively feminizes some but not all behavior patterns shown to differentiate under the influence of perinatal gonadal hormones. In the rat, the critical period for the differentiation of active avoidance behavior appears to span prenatal and early neonatal ontogeny.     

Behavioral and neurobiological effects of prenatal stress exposure in male and female APPswe/PS1dE9 mice

Epidemiological evidence implies a role for chronic stress and stress-related disorders in the etiopathogenesis of sporadic Alzheimer's disease (AD). Although chronic stress exposure during various stages of life has been shown to exacerbate AD-related cognitive deficits and neuropathology in AD mouse models, the role of stress exposure during the prenatal period on AD development and progression remained to be investigated. The present study therefore explored the effects of prenatal maternal stress (PMS) in both male and female APPswe/PS1dE9 mouse offspring in terms of cognition, affect, and AD-related neuropathology. As prenatal perturbations are likely to mediate their effects via alterations in epigenetic regulation, changes in hippocampal DNA methyltransferase 3a, 5-methylcytosine and 5-hydroxymethylcytosine levels were assessed as underlying mechanisms. Repetitive restraint stress during the first week of gestation exerted a sex-dependent effect, with male PMS mice showing spatial memory deficits and a blunted hypothalamus-pituitary-adrenal axis response, while female PMS mice showed improved spatial memory performance, increased depressive-like behavior, as well as a decrease in hippocampal plaque load. In addition, sex differences were observed among APPswe/PS1dE9 mice, independent of PMS (i.e., female mice showed impaired spatial memory performance, higher hippocampal plaque load, altered amyloid precursor protein processing in the CA3 and lower DNA methyltransferase 3a immunoreactivity in the dentate gyrus when compared with male mice of the same age). In conclusion, PMS exposure impacts on the behavioral phenotype and neuropathology of APPswe/PS1dE9 mice. Moreover, given the remarkable sex differences observed, one should not overlook the impact of sex-specific responses to environmental exposures when investigating gene-environment interactions in AD.     

Effects of ether stress on prolactin and corticosterone levels in prenatally-stressed male rats as adults

The effect of a potent prenatal stressor on adult levels of prolactin and corticosterone was investigated in male rats. It was found that prenatal stress had no effect on initial levels of either of these two hormones. Ether stress levels of prolactin were significantly lower in prenatally-stressed animals compared to prenatally-nonstressed subjects, whereas corticosterone levels in response to ether stress were only marginally affected in prenatally-stressed animals reared by prepartally-stressed mothers. It is suggested that alterations in endocrine function in the adult animal may result from prenatal stress effects on the development of neural mechanisms that regulate the hormonal response to ether stress.     

Effects of prenatal stress on formalin-induced acute and persistent pain in adult male rats

Behavioral responses of 90-day-old male offspring from female Wistar rats exposed to restraint stress during the last week of pregnancy were studied in the formalin test. Specific biphasic behavioral response characterized acute (phase 1) and persistent tonic pain (phase 2). The intensity of nociceptive responses (evaluated by the number of flexions+ shakings and by the duration of paw licking) in prenatally stressed rats changed only during phase 2. During interphase, facilitation of the flexion+shakings pattern (but not the licking pattern) in response to nociceptive stimulation was seen. The response intensity during phase 1 and the duration of both phases remained unchanged. Our findings suggest that prenatal stress modulates nociceptive sensitivity in 90-day-old offspring: it affects the duration of tonic (inflammatory), but not of acute pain. It is concluded that different mechanisms are responsible for the effects of prenatal stress on acute and persistent pain in the formalin test.     

孕期应激对子代雌鼠成年后钙结合蛋白Parvalbumin和Calretinin表达的影响

目的　探讨孕期应激对子代雌鼠成年后钙结合蛋白阳性神经元表达的影响。 方法　6只SD孕鼠随机分为孕期应激组（PS组）和对照组（CON组）。PS组孕鼠在妊娠晚期接受限制性应激,CON组不给予孕期应激。子代成年后,PS组和CON组雌性子代随机分别又分为PS-S组,PS-NS组,CON-S组和CON-NS组（n均=6）。PS-S组和CON-S组动物先后接受限制性应激和冰水应激。动物在接受应激后均给与水和酒精喂养,用Western blot检测海马钙结合蛋白Parvalbumin（PV）和Calretinin（CR）蛋白的表达,进一步结合共聚焦免疫荧光组织化学方法检测PV和CR在海马CA1、CA3区和齿状回（dentate gyrus,DG）的表达。 结果　与CON-NS组相比,海马区PV和CR的蛋白表达在CON-S,PS-NS和PS-S组下降,以PS-S组表达最低。PV在海马CA1、CA3区和DG的免疫荧光结果与PV的蛋白表达呈一致性,免疫阳性细胞明显减少;而CR的表达除了在海马CA1区的PS-NS组略有升高外,在其余各组的表达均较减少。与CON-NS组相比,PV和CR在其它各组的蛋白表达和免疫阳性细胞计数差异有统计学意义,其中以PS-S组的表达降低最为有统计学意义（P<0.05）。 结论　孕期应激可影响子代雌鼠成年后海马结构钙结合蛋白PV和CR的表达。     

产前应激对子代的影响及潜在作用机制

Inappropriate diet and stress in maternal pregnancy may affect the development of the offspring. Brain dysfunction and some chronic diseases such as obesity and diabetes in offspring are associated with the factors during maternal pregnancy. Many researches focused on how prenatal stress affected cognitive function and behavior of the offspring and how nutritional modulation might prevent the pathogenesis of such diseases. Here we summarize the effects of prenatal stress on the offspring and the potential mechanism, like hypothalamus-pituitary-adrenal axis(HPA), oxidative stress, apoptosis and inflammation, and the prevention of nutrient to offspring dysfunction by prenatal stress, based on our previous work and some existing references.     

Low temperatures during early development influence subsequent maternal and reproductive function in adult female mice

Challenging conditions early in development can have enduring effects into adulthood. The effects of low temperatures were examined on subsequent sex-specific morphology (anogenital distance [AGD]), maternal care, and reproductive performance in adult female mice. Dams (F0) were maintained either in (1) standard laboratory room temperatures (21 +/- 2 degrees C) or (2) low temperatures (10 +/- 2 degrees C) throughout gestation. Their progeny (F1) either remained in the temperature condition in which they were conceived or were switched to the other temperature condition at 2 days of age until weaning. Reproductive performance and maternal behaviors were assessed in adulthood. F0 dams that were maintained in low temperatures bore larger litters as compared to F0 animals housed in standard temperatures throughout their pregnancy. In contrast, mean litter size was reduced for all groups of F1 females that experienced low temperatures. Infant mortality was elevated in litters of F1 females that were exposed to low temperatures both before and after birth. Prenatal exposure to low temperatures was associated with reduced responsiveness towards the nursing young and decreased maternal aggression in F1 animals. Prenatally treated F1 females had longer, male-like AGDs on Day 2 following birth compared to animals not subjected to experimental manipulations. Our results indicate that exposure to low temperatures during early development impairs reproductive function and is associated with important fitness costs as evidenced by reduced offspring survival. Our findings also suggest that chronic low temperatures experienced only after birth may have less deleterious effects than exposure to a combination of pre- and postnatal or prenatal treatments alone.     

Oxidative stress and protein glycation in primary hypothyroidism. Male/female difference

Oxidative stress (OS) has recently been documented in hypothyroidism, a disease more prevalent in women. In general, OS is reported to be more prevalent in males. However, the effect of gender on OS and protein glycation in hypothyroidism has not been addressed. Blood samples from 37 recently diagnosed primary hypothyroid patients were collected before initiation of thyroxine therapy. Serum glucose, thyroid and lipid profiles were estimated. Glutathione (GSH), malondialdehyde (MDA), protein carbonylation (PCO) and fructosamine levels were analysed. GSH was found to be lower, whereas MDA, fructosamine and PCO levels were higher in male than in female patients. Level of MDA was significantly correlated with fructosamine, protein carbonyls, cholesterol, low-density and high-density lipoprotein cholesterol, triglyceride and GSH in hypothyroid patients. We found OS to be more prevalent in male hypothyroid patients. The positive association of MDA with fructosamine indicates that enhanced lipid peroxidation could be a plausible contributor for accelerated glycation of protein. Considering the negative influence of OS on health, extra attention should be paid to male hypothyroid patients in spite of the low prevalence of this disease in them.     

中晚期孕期束缚应激对子代下丘脑多巴胺能神经元发育的影响

目的　研究中晚期孕期束缚应激对子代下丘脑多巴胺能神经元发育的影响。 方法　使用怀孕SD大鼠,实验组在孕期第15~21 d进行束缚应激,对照组则不受任何干扰。子代大鼠出生的当天为出生后的第0 天。在子代大鼠出生后的第1天（P1）,第7天（P7）和第30天（P30）,分别测子代大鼠的体重,通过免疫组织化学染色和Western Blotting,观察和比较下丘脑内合成多巴胺的关键酶酪氨酸羟化酶（TH）染色像素密度及TH蛋白水平变化。 结果　与正常对照组相比,中晚期孕期束缚应激子代大鼠在P1体重较低,下丘脑TH染色像素密度和TH蛋白水平上调, 这种异常在P7和P30消失。 结论　孕期应激使子代下丘脑多巴胺神经元早期发育异常, 可能是造成子代神经系统行为学异常的原因之一。     

Ameliorative effect of BDNF on prenatal ethanol and stress exposure-induced behavioral disorders

Brain-derived neurotrophic factor (BDNF) plays critical role in neuronal development, function, survival and plasticity of mature neurons. The present experiments investigated whether BDNF ameliorates the damaging effect of prenatal ethanol and stress exposure on behavior in offspring. Prenatal exposure of ethanol and stress combined during gestation inverted sexual partner preference of male offspring, increased social contacts with juvenile male mouse and stereotypic burying activity in the marble-burying test suggesting predisposition to homosexuality and to obsessive-compulsive disorder. Centrally administered BDNF (300 ng i.c.v.) restored sexual female preference of male adult offspring and decreased marble-burying activity. Ameliorative effect was shown in 7-10 days after BDNF administration. The results provide the first evidence that BDNF improves epigenetic impairment of behavior and may have profound implications in the treatment of neurologic disorders induced by early environmental challenges.     

Effects of mild calorie restriction on reproduction, plasma parameters and hepatic gene expression in mice with altered GH/IGF-I axis

The somatotropic axis, the hypothalamic-pituitary-gonadal axis and the nutritional status are deeply interrelated in mammals. Calorie restriction (CR) prolongs lifespan, but usually at some cost to reproduction. Interestingly, many of the physiological characteristics of animals with interruption in the somatotropic axis are shared by CR animals. The level of CR in most studies is 30-60%. We tested if a milder (20%) CR would promote health benefits without inhibiting reproduction in four types of mice with altered somatotropic axis: Ames dwarfs, GHR-KO, and PEPCK-bGH and MT-bGH transgenics. Fertility was not altered by CR in any of the examined groups. Mild CR did not affect final body weights or relative reproductive organ weights; did not alter plasma levels of glucose, insulin, IGF-I, testosterone, progesterone or estradiol; and did not influence hepatic expression of genes related to longevity. Altered activity of the GH/IGF-I axis in the different mice models studied had a major impact on the parameters analyzed. This preliminary study encourages speculation that mild regimens of CR can produce health and longevity benefits without the "costs" of impaired reproductive potential.     

2268例男性不育患者精液参数和生殖激素水平分析

目的探讨男性不育与精液参数和生殖激素水平关系。方法对2268例男性不育患者进行精液参数和生殖激素检测。结果不育患者精子密度、前向运动率、正常形态精子百分率与对照组相比,差异有统计学意义（P〈0.05）,而精液量和PH没有明显差别（P〉0.05）;不育患者卵泡刺激素（FSH）、黄体生成素（LH）、垂体催乳素（PRL）明显高于正常对照组（P〈0.05）,不育患者血清睾酮（T）明显低于对照组（P〉0.05）,而雌二醇（E2）无显著性变化（P〉0.05）。结论对男性不育患者进行精液质量和生殖激素检测是有必要的,对临床确定病因和内分泌治疗提供重要依据。     

Fidgetin knockdown and knockout influences female reproduction distinctly in mice

Microtubule-severing proteins(MTSPs),are a family of proteins which use adenosine triphosphate to sever microtubules.MTSPs have been shown to play an important role in multiple microtubule-involved cellular processes.One member of this family,fidgetin(FIGN),is also involved in male fertility;however,no studies have explored its roles in female fertility.In this study,we found mouse fidgetin is rich within oocyte zona pellucida(ZP) and is the only MTSP member to do so.Fidgetin also appears to int...     

Aggression-promoting and aggression-eliciting properties of estrogen in male mice

Two experiments assessed the aggression-promoting and aggression-eliciting properties of estradiol benzoate (EB). When given daily to gonadectomized adult male mice, EB induced attack behavior toward stimulus males at a level similar to that observed in intact males or castrate males treated with testosterone propionate (TP). A second experiment showed that significantly fewer gonadectomized/olfactory bulbectomized males given EB were attacked by adult males in comparison to similarly prepared TP-treated or intact/olfactory bulbectomized males. Thus, EB is as effective as TP in promoting aggression but is less effective in eliciting fighting.