Mitsuma T, Hirooka Y, Kayama K, Tomari Y, Nogimori T
Fourth Department of Internal Medicine, Aichi Medical University, Japan.
Endocr Regul. 1994 Sep;28(3):125-31.
The effects of hypophysectomy on thyrotropin releasing hormone (TRH), TRH-glycine (TRH-Gly) and pre-pro-TRH (178-199) concentrations in the rat hypothalamus, cerebrum, cerebellum, brain stem, stomach and retina were studied 7 days after the operation. The hypophysectomized rats were administered a single i.p. injection of T4 (500 micrograms/kg), T3 (100 micrograms/kg) or bovine TSH (1.25 IU/kg), and 5 rats of each subgroup were decapitated at 4 hours later. After hypophysectomy, TRH-Gly and pre-pro-TRH (178-199) concentrations in the hypothalamus increased significantly and TRH concentrations decreased after hypophysectomy. After the injection of T4, T3, TRH or TSH TRH-Gly and pre-pro-TRH (178-199) concentration in the hypothalamus of hypophysectomized rats decreased significantly, while that of TRH significantly increased. No changes in TRH, TRH-Gly and pre-pro-TRH (178-199) concentration in other tissues were observed after hypophysectomy or hormone treatment. The findings suggest that hypophysectomy stimulated TRH synthesis and release in the hypothalamus, that TRH, TSH, T3 and T4 regulate hypothalamic TRH levels, and that pro-TRH synthesis in the tissues except the hypothalamus may not be regulated by thyroid hormone.
研究了垂体切除术后7天，大鼠下丘脑、大脑、小脑、脑干、胃和视网膜中促甲状腺激素释放激素（TRH）、TRH-甘氨酸（TRH-Gly）和前-前-TRH（178-199）的浓度变化。对垂体切除的大鼠腹腔注射一次T4（500微克/千克）、T3（100微克/千克）或牛促甲状腺激素（1.25国际单位/千克），每个亚组的5只大鼠在4小时后断头处死。垂体切除术后，下丘脑TRH-Gly和前-前-TRH（178-199）浓度显著升高，TRH浓度降低。注射T4、T3、TRH或促甲状腺激素后，垂体切除大鼠下丘脑TRH-Gly和前-前-TRH（178-199）浓度显著降低，而TRH浓度显著升高。垂体切除或激素处理后，其他组织中TRH、TRH-Gly和前-前-TRH（178-199）浓度未见变化。这些结果表明，垂体切除刺激下丘脑TRH的合成和释放，TRH、促甲状腺激素、T3和T4调节下丘脑TRH水平，且除下丘脑外的组织中前-TRH的合成可能不受甲状腺激素调节。
