The occurrence of precocious puberty in children with primary hypothyroidism is a well recognized but poorly understood phenomenon. Several mechanisms have been proposed, but exceptions can be raised for each hypothesis (Lindsay et al, Am J Dis Child 134, 588, 1980). In 9/12 off-therapy primary hypothyroid children and adolescents (aged 1-16 yrs, 9 prepubertal and 3 pubertal) i.v. TRH (5μg/kg) injection elicited an evident increase of serum LH between 15 and 30 min, which exhausted within 90 min. Mean (± SEM) LH serum levels at 15 (2.22±0.45 ng/ml) and 30 min (2.22±0.43) were significantly (p7 ng/ml)was also recorded in 3/12 hypothyroids. On the contrary FSH serum levels were not substantially modified by TRH bolus, either in the patient or in the control group. An overlap in the pituitary hormonal feed-back mechanism had been hypothesized to explain the occurrence of precocious puberty in primary thyroid failure (Van Wyk and Grumbach, J Pediatr 57, 416, 1960). The nonspecific LH-releasing effect of TRH in our patients especially evident in the pubertal ones supports such hypothesis.
展开▼
机译：原发性甲状腺功能减退的儿童中性早熟的发生是公认的但知之甚少的现象。已经提出了几种机制，但是可以为每种假设提出例外（Lindsay等，Am J Dis Child 134，588，1980）。在9/12的非治疗性原发性甲状腺功能减退儿童和青少年中（年龄1-16岁，青春期前9例，青春期3例）。 TRH（5μg/ kg）注射引起15至30分钟之间的血清LH明显增加，并在90分钟内耗尽。在3/12甲状腺功能减退的甲状腺中也记录了平均（±SEM）LH血清水平在15（2.22±0.45 ng / ml）和30分钟（2.22±0.43）时显着（p7 ng / ml）。相反，无论是在患者还是在对照组中，TRH推注均未使FSH血清水平得到实质性改变。垂体激素反馈机制的重叠被认为可以解释原发性甲状腺功能衰竭时性早熟的发生（Van Wyk and Grumbach，J Pediatr 57，416，1960）。 TRH对我们患者的非特异性LH释放作用尤其在青春期患者中得到证实，支持了这一假说。
展开▼
