Nazian S J
Department of Physiology & Biophysics, College of Medicine, University of South Florida, Tampa 33612, USA.
J Androl. 2001 May-Jun;22(3):491-6.
Although leptin has been implicated as an important factor in triggering the onset of puberty in females, much less is known about the role of this adipose tissue hormone in the sexual maturation of males. Previous work in the rat has suggested that the peripubertal rise in testosterone precedes an increase in leptin secretion, and it has been suggested that the testosterone rise induces the leptin increase. These studies examined some of the interactions between leptin secretion and the peripubertal testosterone rise in male rats. Serum leptin concentrations were significantly elevated in young adult male rats compared with immature rats. Cultured epididymal fat pads obtained from adult animals secreted significantly more leptin than did those obtained from immature rats. Castration of immature rats with or without testosterone replacement for 1 week did not result in a significant change in either the serum leptin concentrations or the ability of the epididymal fat pad to secrete leptin. Exposure of epididymal fat to 5 ng/mL of testosterone in vitro resulted in a significantly enhanced secretion of leptin into the media compared with plain media controls. These results confirmed that there is an increase in serum leptin concentrations with sexual maturation in the male rat. They also suggest that this increase is due to an enhanced ability of adipose tissue to secrete leptin. Within a normal physiologic range, testosterone may play a role in inducing this increased ability to secrete leptin.
尽管瘦素被认为是触发女性青春期开始的一个重要因素，但对于这种脂肪组织激素在男性性成熟过程中的作用却知之甚少。此前在大鼠身上进行的研究表明，青春期前睾酮水平的升高先于瘦素分泌的增加，并且有人提出睾酮水平的升高会诱导瘦素增加。这些研究探讨了雄性大鼠瘦素分泌与青春期前睾酮水平升高之间的一些相互作用。与未成熟大鼠相比，年轻成年雄性大鼠的血清瘦素浓度显著升高。从成年动物获取的附睾脂肪垫培养物分泌的瘦素明显多于从未成熟大鼠获取的脂肪垫培养物。对未成熟大鼠进行去势手术，无论是否进行为期1周的睾酮替代，血清瘦素浓度或附睾脂肪垫分泌瘦素的能力均未发生显著变化。与普通培养基对照相比，体外将附睾脂肪暴露于5 ng/mL睾酮中会导致瘦素向培养基中的分泌显著增加。这些结果证实，雄性大鼠随着性成熟血清瘦素浓度会升高。它们还表明，这种升高是由于脂肪组织分泌瘦素的能力增强所致。在正常生理范围内，睾酮可能在诱导这种分泌瘦素能力增强方面发挥作用。
