Amatruda J M, Hochstein M, Hsu T H, Lockwood D H
Int J Obes. 1982;6(2):183-9.
Previous studies have indicated dysfunction of the hypothalamic-hypophyseal axis in obesity. We have studied 12 obese males to further characterize the extent of this dysfunction. The hypothalamic-hypophyseal-gonadal axis is normal as determined by the testicular response to human chorionic gonadotropin (hCG), the pituitary response to 200 micrograms gonadotropin-releasing hormone (GnRH), and the hypothalamic-pituitary-testicular response to clomiphene. Although L-dopa suppresses prolactin normally, the ability of thyrotropin releasing hormone (TRH) to stimulate the release of prolactin and thyroid stimulating hormone (TSH) is blunted. These latter responses are inversely related to the degree of obesity. The response to chlorpromazine, a hypothalamic stimulus for prolactin secretion, is also blunted, and to a greater extent than the prolactin response to TRH. These data indicate that exogenous obesity in males is associated with more extensive hypothalamic and pituitary dysfunction than previously realized. The abnormalities with regard to prolactin and TSH release become progressively worse when body weight exceeds 200 percent of ideal. In addition, when evaluating pituitary function with regard to gonadotropin release, obese males may have an abnormal response to 100 micrograms GnRH but respond normally to 200 micrograms.
先前的研究表明肥胖症患者存在下丘脑 - 垂体轴功能障碍。我们对12名肥胖男性进行了研究，以进一步明确这种功能障碍的程度。通过睾丸对人绒毛膜促性腺激素（hCG）的反应、垂体对200微克促性腺激素释放激素（GnRH）的反应以及下丘脑 - 垂体 - 睾丸对克罗米芬的反应来判断，下丘脑 - 垂体 - 性腺轴是正常的。虽然左旋多巴能正常抑制催乳素，但促甲状腺激素释放激素（TRH）刺激催乳素和促甲状腺激素（TSH）释放的能力减弱。后一种反应与肥胖程度呈负相关。对氯丙嗪（一种下丘脑催乳素分泌刺激物）的反应也减弱，且比催乳素对TRH的反应减弱程度更大。这些数据表明，男性外源性肥胖与比之前认识到的更广泛的下丘脑和垂体功能障碍有关。当体重超过理想体重的200%时，催乳素和TSH释放方面的异常会逐渐加重。此外，在评估垂体促性腺激素释放功能时，肥胖男性对100微克GnRH可能有异常反应，但对200微克GnRH反应正常。
