对氯烯雌酚醚防治雌性大鼠去势后骨丢失的评价

目的：了解氯烯雌酚醚对去势雌性大鼠骨代谢的影响。方法：鼠龄７０天的Ｗｉｓｔａｒ雌鼠４８只，分别予假性手术与注射用油（ＳＶ组）、去势与注射用油（ＯＶ组）、假性手术与氯烯雌酚醚（ＳＥ组）及去势与氯烯雌酚醚（ＯＥ组）等处理，双侧卵巢去势或假性手术后７天，于每晚腹腔注射氯烯雌酚醚或注射用油４ｍｌ／ｋｇ，共４５天。处死大鼠时，测定子宫湿重，同时收集第１２胸椎和左胫骨制成脱钙骨切片，行骨组织形态计量学测定。结果：４组间子宫重量差异均有显著性。骨组织形态计量学显示，（１）ＯＶ与ＳＶ、ＳＥ及ＯＥ组间差异有显著性；（２）ＯＥ、ＳＥ和ＳＶ组间差异无显著性。结论：氯烯雌酚醚能抑制Ｗｉｓｔａｒ雌鼠去势后的骨丢失，减缓去势后的子宫萎缩，对骨骼有雌激素样的保护作用。     

Androgenic control of porphyrin in the harderian glands of the male syrian hamster is modulated by the photoperiod,which suggests that the sexual differences in porphyrin concentrations in this gland are important functionally

Background: The porphyrin concentrations of the Harderian glands of Syrian hamsters show marked sexual differences, with male levels being much lower than those of females. Porphyrinogenesis is inhibited by androgens, so orchidectomy leads to elevated male porphyrin concentrations; however, a number of other procedures (some of which also lower androgen levels) prevent this. We studied the effects of short-day photoperiods and melatonin on Harderian porphyrin concentrations. Methods: Intact, castrated, or pinealectomized hamsters of both sexes were exposed to long-day or short-day photoperiods. Intact or castrated hamsters were given melatonin injections in the morning or the afternoon, or were given beeswax pellets containing melatonin. After a variable period, Harderian glands were dissected and porphyrins were measured. Results: Prolonged short-day exposure (13 weeks) led to increased Harderian porphyrin concentrations and this rise was prevented by pinealectomy. The rise in Harderian porphyrins following short-day exposure was small, compared with that following castration. Short-day photoperiods also prevented the rise in porphyrin levels associated with castration and this effect was prevented by removal of the pineal. Melatonin injections, whether given in the morning or in the afternoon, had no effect on Harderian porphyrin concentration of castrated male hamsters. Continuous release melatonin pellets reduced the postcastrational rise in porphyrin levels in one experiment, while having no effect in another. In female hamster, neither short photoperiods nor melatonin pellets influenced Harderian porphyrin concentrations. Conclusions: These results suggested that a factor from the pineal gland helps maintain the low levels of porphyrin which are characteristic of male Harderian glands, despite the decrease in androgen levels which typically results from exposure to short days. Morning and afternoon injections of melatonin and continuous release melatonin pellets failed to resolve the question of whether this pineal factor is melatonin. Our results demonstrated that low male and high female porphyrin levels are maintained in Syrian hamsters, despite seasonal variations in the hormonal milieu, suggesting that these sexual differences are important for the (still unestablished) function of the Harderian glands in this species. © 1994 Wiley-Liss, Inc.     

Influence of testosterone on pup killing in the rat is modified by prior experience.

The usual response of the adult male rat which is placed together with newborn rat pups for the first time is to kill and eat the pups. In past experiments castration of the male blocked this behavior, and replacement therapy with testosterone propionate (TP) maintained the behavior. In the present experiments this relationship between testosterone and pup-killing behavior was modified by giving the animals prior killing or nonkilling experience. In general, experienced killers continued to kill on a retest after 30 days of testosterone deprivation, and experienced nonkillers tended not to kill on the retest even though they were given daily treatment with testosterone for thirty days prior to retesting.     

Maintained aggressive behavior in gonadectomized male Siamese fighting fish (Betta splendens)

Adult male Betta splendens were gonadectomized and tested twice for aggressive behavior two weeks later. In a mutual viewing test environment, it was found that gonadectomized animals maintained their aggressive behavior on all six indices of aggression at a level equal to controls. Animals that showed some testis regeneration and sham operated fish were also equal to controls. The results are interpreted to mean that adult aggressive behavior in male B. splendens may not be under the control of gonadal hormones. Pituitary gonadotropins, interrenal gland, and critical period hypotheses are given as possible explanations of the maintained aggressiveness following castration.     

Development of olfactory-guided behavior in the golden hamster.

Hamster pups were tested for an odor preference every day from 1-16 days of age with shavings from their home cage and with clean wood shavings. The hamster pups showed a clear preference for their home cage shavings by 8 days of age. They were then tested for preferences with other odor combinations. Tests for preference with other odor pairs indicate that this preference is due to a change in the hamsters rather than a change in the stimulus. In these tests the hamster pups did not demonstrate a preference for their home shavings over shavings in which a nonlactating female had lived. Further tests will have to be done to determine how specific the hamster pup's olfactory preferences are.     

Effects of hormonal replacement with androgens and estrogens on male sexual behavior and plasma levels of these steroids in gonadectomized golden hamsters (Mesocricetus auratus)

Because the endocrine control of sexual behavior in male hamsters remains controversial, this study analyzed the influence of different androgens and estrogens in the regulation of masculine, sexual behavior (MBS). Aromatizable androgens: androstenedione (A) and testosterone (T), a non-aromatizable androgen: 5α-dihydrotestosterone (DHT), as well as estrogens (E₂ and E₁) alone or in combination with DHT, were administered in gonadectomized, sexually experienced males, for 3 weeks. In addition, plasma levels of these steroids were determined. Gonadectomy completely suppressed masculine sexual behavior (MSB) after 4 weeks. Both A and T replacements restored all the sexual behavior parameters in castrated hamsters by the 3rd week of treatment, with A being more potent in restoring all copulatory series and maintaining all MSB parameters, including long intromissions. Castrated males treated with DHT showed little interest in the female and did not display any copulatory behavior. Gonadectomized males treated with estrogens alone showed active anogenital investigation and displayed some mounts, but did not ejaculate. Males treated with estrogens combined with DHT had longer latencies and less number of ejaculations than males treated with aromatizable androgens. Long intromissions were observed only in males treated with T or A. Plasma levels of A were significantly higher than T levels in intact males. In males treated with A both androgens and estrogens were present in plasma. These results support the notion that aromatizable androgens, mainly A, but not non-aromatizable androgens or even estrogens in combination with DHT, play a relevant role in the endocrine regulation of MSB in the golden hamster.     

阉割和睾酮替代对大鼠应激免疫抑制蛋白的影响

目的 :研究阉割和睾酮替代对束缚应激模型大鼠血清中应激免疫抑制蛋白的影响。方法 :成年雄性SD大鼠随机分为正常对照组、假手术组、阉割组、阉割后睾酮替代组。每组 10～ 12只。以上各组随机抽出一半给予束缚应激 ,另一半作为不应激对照。观察各组大鼠血清对ConA诱导的淋巴细胞转化的作用 ,作为反映血清中应激免疫抑制蛋白含量的指标。在离体实验中观察不同浓度的睾酮对淋巴细胞转化的直接作用。结果 :阉割可促进应激大鼠血清中应激免疫抑制蛋白的产生 ,睾酮替代可对抗这一作用。结论 :睾酮可在一定范围内对抗应激免疫抑制蛋白的产生。     

尼尔雌醇作用下去势雌兔骨组织形态计量学改变

目的：评估尼尔雌醇对绝经后骨质疏松症的疗效，并探讨其机理。方法：将３０只雌性新西兰兔随机分成３组（每组１０只）：治疗组［摘除卵巢＋尼尔雌醇（每月２ｍｇ）］、模型组（摘除卵巢）和正常对照组（假手术），６个月后处死取材，并在处死前行四环素标记，ＶＩＤＡＳ图象分析系统下作骨组织形态计量学测定。结果：治疗组的单位体积骨小梁骨量（ＢＶ／ＴＶ）、相对类骨质量（ＯＶ／ＢＶ）、成骨细胞指数（ＯＢＩ）和组织水平的骨形成速率［ＢＦＲ（Ｔ）］明显高于模型组和（或）正常对照组。结论：尼尔雌醇能增加成骨细胞数量，可能是一种成骨细胞募集和（或）增殖的刺激剂。     

十一酸睾酮对雄性家兔髂动脉内膜损伤后的修复作用

目的观察十一酸睾酮对雄兔髂动脉内膜损伤后的修复作用。方法成熟雄性日本大耳白兔25只,随机分成5组,每组5只:假手术组(不切除睾丸和附睾)、模型组、小剂量组(手术后补充睾酮3mg/kg)、中剂量组(手术后补充睾酮6mg/kg)和大剂量组(手术后补充睾酮12mg/kg),后4组均切除双侧睾丸和附睾。所有动物手术后第14d行右侧髂动脉内皮剥脱术。手术后第7、14和第21d肌肉注射十一酸睾酮,假手术组和模型组肌注生理盐水。于不同时间测定血清总睾酮。第28d处死动物,取损伤血管段,应用扫描电镜和HE染色观察髂动脉内膜的修复情况。结果光镜下观察发现,模型组、小剂量组和中剂量组动脉内膜增生严重,大剂量组内膜增厚程度明显减低,接近假手术组。模型组、小剂量组和中剂量组的髂动脉内膜/中膜面积比值分别是1.25±0.10、0.90±0.10和0.74±0.11,明显高于假手术组(0.22±0.05;P<0.01)。大剂量组的髂动脉内膜/中膜面积比值为0.26±0.07,接近于假手术组(P>0.05)。扫描电镜观察发现,假手术组动物髂动脉内皮光滑,整齐连续,模型组几乎未见到有内皮细胞再生,小剂量组内皮有散在覆盖,中剂量组片状覆盖,大剂量组内皮细胞修复明显,排列趋于正常,偶有缺失。在手术后第28d大剂量组血清总睾酮水平接近假手术组,其它组在不同时间点均低于假手术组。结论生理水平的睾酮具有保护雄性家兔血管内皮,抑制动脉损伤后内膜增生的作用。