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11.
Reproduction stops among the majority of prairie voles (Microtus ochrogaster) during the winter. Short day lengths suppress male reproductive function dramatically in the laboratory, but photoperiod exerts only subtle effects on female reproductive function. Thus, the regulation of seasonal breeding in this species remains partially unspecified. In contrast to commonly studied rodents, female prairie voles do not undergo spontaneous estrous cycles; rather, they are induced into estrus by exposure to chemosignals expressed in conspecific male urine. In the present study, the hypothesis was tested that seasonal breeding among female prairie voles in the field reflects photoperiod-mediated changes in the responsiveness of the chemosensory system to male urine. Responsiveness was assessed by localizing the product of the c-fos immediate early gene with an immunocytochemical procedure. Female prairie voles were maintained in either long (LD 16:8) or short (LD 8:16) photoperiods from birth until adulthood, and exposed to either male urine or skim milk. Immunocytochemistry forfos protein revealed an increased number of immunoreactive cells within the accessory olfactory system of female prairie voles, including the accessory olfactory bulbs, granule cell layer, as well as the medial and cortical divisions of the amygdala 1 h after exposure to a single drop of urine as compared to individuals exposed to skim milk. The number of immunoreactivefos cells induced in females by conspecific male urine was also affected by photoperiod; short day females displayed fewer immunoreactivefos neurons in the accessory olfactory system as compared to long-day animal. Taken together, these results indicate that similar mechanisms underlie the responses of different rodent species to the chemosignals of conspecifics and that the pattern offos expression observed in the present study has functional significance for the regulation of reproduction in prairie voles.  相似文献   
12.
Summary Ninety-one percent (n=182) of the female members of South Australian representative squads in 14 sports volunteered to act as subjects. Twenty-seven percent of them had represented Australia. The underwater weighing method together with the measurement of residual volume (RV) by helium dilution were used to determine body density (BD); the percent body fat (% BF) was then computed according to Siri.A stepwise multiple regression analysis yielded a correlation coefficient (R) of 0.863 between the criterion (BD) and the best weighted sum of predictors (anthropometric variables): BD (g·cm–3)=1.14075–0.04959 (log10 triceps, subscapular, supraspinale and calf skinfolds in mm)+0.00044 (age in decimal years)–0.000612 (waist girth in cm)+0.000284 (height in cm)–0.000505 (gluteal girth in cm)+0.000331 (breast girth in cm).Only those predictors which resulted in a statistically significant increase inR (p0.05) were included. The standard error of estimate of 0.00597 g · cm–3 was equivalent to 2.7% BF at the mean. This equation was shown to be largely population specific. There was a range of 7.6–35.8% of BF and the overall mean of 18.5% was significantly lower (p<0.001) than that of 23.4% obtained on a moderately active reference sample of similar age (n=135). If group sizes of only one or two are regarded as too small for meaningful comparison, then the lowest mean of 13.5% was achieved by the long-distance runners (n=14). The highest averages were registered by the heavyweight rowers (24.2%;n=7) and soccer players (22.0%;n=11). The overall average for games players (n=107) was 19.4%.This study was supported by a grant from the National Health and Medical Research Council of Australia  相似文献   
13.
The effects of intracerebral implants of steroid hormones on scent marking in the female gerbil (Meriones unguiculatus) were studied in two experiments. In Experiment 1 various steroids were implanted alone or in combination into the preoptic and anterior hypothalamic area of ovariectomized females. Unilateral implants of testosterone + estrogen, estrogen, estrogen + progesterone, testosterone and testosterone + progesterone stimulated a significant level of marking when compared to controls. Experiment 2 utilized bilateral implants of estrogen dissolved in paraffin in order to explore the distribution hormone sensitive areas in the brain which might be important in the regulation of scent marking in the female gerbil. Pellets of estrogen-paraffin were implanted stereotaxically into either the anterior hypothalamus, preoptic area, septum, hippocampus, thalamus, amygdala or anterior olfactory nucleus of ovariectomized females. Total dosage of hormone implanted was 8.2–8.4 μg. A significant level of marking resulted in animals receiving implants into the anterior hypothalamus, preoptic area and septum when compared to controls. Marking appeared at about the same rate in each of these groups; however, the level of marking attained differed. By the last trial, anterior hypothalamic implanted animals were marking significantly more often than animals in either the preoptic or septum groups. Although there was no evidence of ieakage from the brain, the data suggested that some rapid diffusion of hormone, largely restricted to the brain, was taking place or that the three areas were differentially responsive to the hormone. The data do indicate that some localization of function does exist with respect to regulation of scent marking in the female.  相似文献   
14.
目的初步研究敲除Fm r1基因对动物生殖功能的影响。方法6~8周龄雌性Fm r1基因敲除小鼠24只,分为对照组、春季超排组和冬季超排组,每组8只,进行超排,用放射免疫分析法测定超排前后血清雌二醇(E2)、孕酮(P)、促黄体生成素(LH)和促卵泡生成素(FSH)含量,以及不同季节的超排卵数,并进行统计学处理和分析。结果超排后小鼠血清中P和LH含量明显增加[(24.43±13.33)比(1.60±0.46);(173.86±112.09)比(0.36±0.23),P<0.01]。与冬季(11.44±5.93)比较,春季(37.25±13.91)的超排卵数明显增加(P<0.01)。结论雌性Fm r1基因敲除小鼠的生殖系统功能没有明显异常。与正常小鼠一样,Frm 1基因敲除小鼠机体内P和LH的分泌随动物的生理发育时期而变化。其超排效果随季节而有显著不同。  相似文献   
15.
目的 探讨在押女性毒品犯人格的基本特征、类型特征及其影响因素。方法 以252名在押女性毒品犯为被试,对CPI的测验数据进行t检验、Z检验和F检验。结果 ①女性毒品犯不仅与常模团体相比较具有显著特征.而且与男性毒品犯相比较也存在特殊性;②女性毒品犯在4种人格类型上的分布不平衡.较多地在Delta型;③民族、地域、年龄及关押时间对女性毒品犯的人格特征的变异均有一定影响.但减刑次数未见反映出被试人格积极改变的效果。结论 女性毒品犯广泛而明显的消极性人格特征,并与民族、地域、年龄及关押时间有关。  相似文献   
16.
Previous literature presents discordant results on the relationship between physiological and subjective sexual arousal in women. In this study, the use of hierarchical linear modeling (HLM) revealed a significant concordance between continuous measures of physiological and subjective sexual arousal as assessed during exposure to erotic stimuli in a laboratory setting. We propose that past studies that have found little or no association between the two measures may have been in part limited by the methodology and statistical analyses employed.  相似文献   
17.
目的探讨不孕不育及自发流产与染色体核型异常的关系,指导临床对这些疾病的诊断。方法采集922例生殖异常患者外周静脉血,进行淋巴细胞培养,常规方法收获细胞,低渗、固定、制片、经G显带处理、镜检,进行观察研究。结果922例患者共检出异常核型66例,总检出率7.16%。其中,易位21例,倒位21例,克氏综合征18例,X-三体综合征2例,Turner综合征伴X染色体缺失1例,Y染色体缺失1例,环状21号染色体1例,额外标记染色体1例,及常见染色体多态性大Y染色体63例,发生率13.35%。结论染色体异常是导致不孕不育及自发流产的重要原因之一,对生殖异常患者进行染色体检查可为临床诊断和优生优育提供依据。  相似文献   
18.
目的探讨柳州地区籍女性新生儿黄疸儿G6PD基因突变类型与其临床表现特点之间的关系.方法采用基因芯片技术检测了7例柳州地区籍女性新生儿黄疸儿的G6PD基因突变类型,并对其临床表现特点进行分析.结果 (1)7例女患儿G6PD基因突变共检出4种类型,包括G1388A、A95G、G1376T及G392T,其中5例为杂合子.(2)G6PD酶学检查5例表现为中间型,且临床黄疸症状较轻,治疗效果好.结论柳州地区籍女性新生儿黄疸儿的G6PD基因突变类型多见G1388A、A95G、G1376T突变,以杂合子改变占多数.  相似文献   
19.
Dieting and stress are important in the etiology and maintenance of eating disorders, and dieting strongly predicts stress-induced overeating in humans. We hypothesized that caloric restriction and stress interact in a unique manner to promote binge eating. To test this hypothesis, a group of young female rats were cycled through a restriction period (4 days of 66% of control food intake) followed by 6 days of free feeding prior to being stressed by acute foot shock. After three of these cycles, the food intake of rats exposed only to restriction (R), or only to stress (S), did not differ from controls. However, R+S rats that were restricted and refed, despite normal body weight and food intake after free feeding, engaged in a powerful bout of hyperphagia when stressed (Experiment 1). The R + S effect was replicated in an older group of rats (Experiment 2). The hyperphagia was characteristically binge-like, it constituted a 40% selective increase in highly palatable (HP) food (P < .001) over a discrete period of time (within 24 h post-stress), and reflected feeding for reward (higher HP:chow ratio) over metabolic need as occurred after restriction (higher chow:HP ratio). Subsequent experiments revealed that binge eating did not occur if only chow was available (Experiment 3) or if restriction-refeeding (R-R) did not proximally precede stress (Experiment 4). Experiment 5 revealed that a history of R-R cycles followed by only one stress episode was sufficient to increase intake to 53% above controls as early as 2 h after stress (P < .001). This animal model of binge eating should facilitate investigations into the neurochemical changes induced by dieting and environmental stress to produce disordered eating and provide a preclinical tool to test preventive strategies and treatments more relevant to bulimia nervosa, multiple cases of binge eating disorder (BED) and binge-purge type anorexia nervosa.  相似文献   
20.
Effects of aging on estrous cycles and LH release in response to luteinizing hormone releasing hormone (LHRH), castration, and estradiol benzoate were studied in the female golden hamster (Mesocricetus auratus). About 80% to 90% of female golden hamsters still cycled regularly when reaching 19–22 months of age. However, some animals showed age-induced irregularity of the estrous cycle which included an interruption of complete absence of estrous vaginal discharge. Young female hamsters (3–5 months) had significantly (p<0.01) higher basal LH concentration than old animals (19–22 months) in the morning of each stage of estrous cycle. LHRH elicited about 20–30 fold increase in serum LH concentrations in both young and old hamsters. No significant difference in LH release was observed between young and old hamsters in response to LHRH. In acyclic hamsters, the peak of LH release in response to LHRH was delayed. LHRH-induced LH release was greater in the morning of proestrus than during diestrus in both young and old hamsters. LH increase was significantly greater in the young than in old hamsters on the 13th and 15th day after castration. However, positive feedback stimulation of LH release by estradiol benzoate was the same in both young and old hamsters. These results indicate that in the female hamster, LH response to acute stimuli such as LHRH and estrogens is the same in the young as in the old animal and that circulating basal LH concentration may decrease or its degradation or clearance may increase during the aging process in female golden hamsters. Irregularity of estrous cycles in aging hamsters may be related to delayed responsiveness of pituitary LH to LHRH stimulation.  相似文献   
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