Wang Cheng, Medan Mohamed S, Shimizu Keiko, Kojima Chihiro, Itoh Mariko, Watanabe Gen, Taya Kazuyoshi
Laboratory of Veterinary Physiology, Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Tokyo, Japan.
Endocrine. 2005 Jun;27(1):75-81. doi: 10.1385/ENDO:27:1:075.
Leptin is one of the most important factors linking nutrition and reproduction. In the present study, plasma concentrations of leptin during pregnancy and early lactation in the Japanese monkey were determined. Plasma concentrations of gonadotropins, immunoreactive (ir-)inhibin, and steroid hormones were also measured. Plasma concentrations of leptin significantly increased during the second quarter of pregnancy and progressively elevated throughout pregnancy. During the fourth quarter of pregnancy, leptin levels reached up to 89 and 64 times of those during prepregancy and first quarter of pregnancy periods, respectively. After parturition, the circulating leptin level abruptly decreased. During the first 10 d of lactation, its average level decreased to the levels of the second quarter of pregnancy. Plasma irinhibin and estradiol-17beta were elevated throughout the pregnancy and decreased after parturition, and both of them were positively correlated with leptin levels during the whole pregnancy and early lactation. Plasma concentrations of progesterone significantly increased during the first quarter of pregnancy and kept at a higher level compared with prepregnancy and sharply decreased after parturition. Placental homogenates contain a large amount of leptin protein. These results suggest that placenta secretes a large amount of leptin and may be another source of leptin during pregnancy in Japanese monkeys. In addition, high correlations among leptin, irinhibin, and estradiol-17beta during these stages suggest that these hormones may have important regulating roles on leptin secretion during pregnancy in the Japanese monkey.
瘦素是连接营养与生殖的最重要因素之一。在本研究中，测定了日本猴孕期和早期哺乳期血浆中瘦素的浓度。还测量了促性腺激素、免疫反应性（ir-）抑制素和类固醇激素的血浆浓度。孕期第二个季度血浆瘦素浓度显著增加，并在整个孕期逐渐升高。在孕期第四个季度，瘦素水平分别达到孕前和孕期第一个季度的89倍和64倍。分娩后，循环瘦素水平急剧下降。在哺乳的前10天，其平均水平降至孕期第二个季度的水平。整个孕期血浆ir抑制素和雌二醇-17β升高，分娩后下降，且二者在整个孕期和早期哺乳期均与瘦素水平呈正相关。孕期第一个季度血浆孕酮浓度显著增加，与孕前相比保持在较高水平，分娩后急剧下降。胎盘匀浆含有大量瘦素蛋白。这些结果表明，胎盘分泌大量瘦素，可能是日本猴孕期瘦素的另一个来源。此外，这些阶段瘦素、ir抑制素和雌二醇-17β之间的高度相关性表明，这些激素可能对日本猴孕期瘦素分泌具有重要调节作用。
