Catecholamines stimulate testicular steroidogenesis in vitro in the Siberian hamster, Phodopus sungorus.
Catecholamines stimulate testicular steroidogenesis in vitro in the Siberian hamster, Phodopus sungorus.
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儿茶酚胺在西伯利亚仓鼠（Phodopus sungorus）的体外刺激睾丸类固醇生成。
DOI：
10.1095/biolreprod48.4.883
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发表时间：
1993
影响因子：
3.6
通讯作者：
Began,T
中科院分区：
文献类型：
--
作者：
Mayerhofer,A;Bartke,A;Began,T
我们已经研究了直接影响的儿茶酚胺对睾丸睾酮生产的季节性繁殖的物种，西伯利亚仓鼠，Photopus sungorus。将来自性腺活跃的长光周期（LD）暴露和性腺退化的短光周期（SD）暴露的动物的睾丸实质与去甲肾上腺素、肾上腺素、β肾上腺素受体激动剂异丙肾上腺素或α肾上腺素受体激动剂苯肾上腺素孵育6小时（均为10 μ M），以及各种浓度的去甲肾上腺素（10 nM-10 μ M）和10 M去甲肾上腺素（含或不含hCG）（0.7、3.1和12.5 mIU/ml）。此外，在含有10 IM去甲肾上腺素的孵育物中检测α-肾上腺素受体拮抗剂哌唑嗪和β-肾上腺素受体拮抗剂普萘洛尔（50 RM）的作用。在LD和SD西伯利亚仓鼠睾丸的孵育中，去甲肾上腺素是最有效的刺激睾酮的产生，其次是肾上腺素和苯肾上腺素，而异丙肾上腺素未能增加睾酮的积累。去甲肾上腺素的刺激作用是剂量依赖性的，并防止与哌唑嗪共孵育，但不受普萘洛尔共孵育。与各种剂量的hCG组合，去甲肾上腺素未能刺激睾酮产生高于单独使用hCG获得的水平。这些数据表明，睾丸受体介导的行动，儿茶酚胺睾丸类固醇激素在Photopus sungorus是α 1-亚型，结果按照先前的研究在金黄地鼠。然而，本研究的结果是显着不同的结果，在金黄地鼠的睾丸类固醇生成的响应性，儿茶酚胺的光周期的影响。因此，在金黄地鼠，季节性光周期相关的性腺活动的过渡到静止是伴随着收购的反应睾丸类固醇生成的儿茶酚胺。相比之下，睾丸的LD暴露和SD暴露的睾丸的Photopus同样能够响应儿茶酚胺能刺激。然而，这种儿茶酚胺作用在LD动物中可能仅具有次要的重要性，其中hCG对睾酮产生具有非常强的刺激作用，其增加超过基础水平70-90倍，而儿茶酚胺的作用小一个数量级。相比之下，在SD动物睾丸的孵育中，hCG的刺激作用（约为基础值的5-10倍）与去甲肾上腺素的作用（4倍基础产量）在相同的范围内。因此，SD睾丸中儿茶酚胺能刺激的相对影响远大于LD睾丸。睾丸中的儿茶酚胺能输入可能被视为LH释放生理抑制期间LH的备用系统。此外，无论睾丸的功能状态，儿茶酚胺可能参与调节睾酮的产生在西伯利亚仓鼠施加一个恒定的“微调”的影响睾丸间质细胞，这可能是直接或间接通过旁分泌相互作用与支持细胞或其他睾丸细胞类型。
We have examined direct effects of catecholamines on testicular testosterone production in a seasonally breeding species, the Siberian hamster, Phodopus sungorus. Testicular parenchyma from gonadally active long photoperiod (LD)-exposed and gonadally regressed short photoperiod (SD)-exposed animals was incubated for 6 h with norepinephrine, epinephrine, betaadrenoreceptor agonist isoproterenol, or alpha-adrenoreceptor agonist phenylephrine (all at 10} IM), as well as with various concentrations of norepinephrine (10 nM-10 iLM), and 10 M norepinephrine with or without hCG (0.7, 3.1, and 12.5 mIU/ml). In addition, effects of alpha-adrenoreceptor antagonist prazosin and beta-adrenoreceptor antagonist propranolol (50 RM) were tested in the incubations containing 10 IM norepinephrine. In the incubations of testes from both LD and SD Siberian hamsters, norepinephrine was most effective in stimulating testosterone production, followed by epinephrine and phenylephrine, while isoproterenol failed to increase testosterone accumulation. The stimulatory effects of norepinephrine were dose-dependent and were prevented by coincubation with prazosin, but not affected by coincubation with propranolol. In combination with various doses of hCG, norepinephrine failed to stimulate testosterone production above the levels obtained with hCG alone. These data indicate that the testicular receptors mediating the action of catecholamines on testicular steroidogenesis in Phodopus sungorus are of the alpha 1-subtype, a result in accordance with a previous study in the golden hamster. However, the results of the present study are strikingly different from the findings obtained in the golden hamster in terms of the effects of photoperiod on the responsiveness of testicular steroidogenesis to catecholamines. Thus, in the golden hamster, the seasonal photoperiod-related transition from gonadal activity to quiescence is accompanied by an acquisition of responsiveness of testicular steroidogenesis to catecholamines. In contrast, the testes of both LD-exposed and SD-exposed testes of Phodopus are equally able to respond to catecholaminergic stimuli. However, this catecholamine effect may be of only minor importance in the LD animal, in which hCG has a very strong stimulatory action on testosterone production with increases 70-90-fold over basal levels, while the effects of catecholamines are an order of magnitude smaller. In contrast, in the incubations of testes from SD animals, the stimulatory action of hCG (approximately 5-10 times basal values) was in the same range as the effect of norepinephrine (4 times basal production). Thus, the relative impact of catecholaminergic stimuli in the SD testis is by far greater than in the LD testis. Perhaps catecholaminergic input in the testis could be viewed as a back-up system for LH during the time of physiological suppression of LH release. Moreover, regardless of the functional state of the testis, catecholamines may participate in the regulation of testosterone production in the Siberian hamster by exerting a constant" fine-tuning" effect on testicular Leydig cells, which could be either direct or indirect via paracrine interactions with Sertoli cells or other testicular cell types.