Siddiqui R A, McCutcheon S N, Mackenzie D D, Blair H T, Ormsby J E, Gluckman P D, Breier B H
Department of Animal Science, Massey University, Palmerston, New Zealand.
Acta Endocrinol (Copenh). 1989 Nov;121(5):686-90. doi: 10.1530/acta.0.1210686.
A study was undertaken to investigate the role of testosterone in regulating growth and circulating levels of insulin-like growth factor-I in male mice from lines divergently selected on the basis of plasma IGF-I. Controls of each lines were sham-operated at 10 days of age and treated with peanut oil from day 14 to day 70. A second group, which was castrated at 10 days and treated with testosterone enanthate (0.5 micrograms.(g body weight)-1.day-1) from day 14 to 70, did not differ from controls in body weight but had higher plasma IGF-I concentrations. Delaying testosterone therapy until day 42 in a third group retarded growth, with body weights being significantly lower than those of other two groups from days 35 to 56. However, plasma IGF-I levels in this group were not different from those of controls. Effects of line and treatment were additive. It is concluded that the greater pubertal growth of high-line compared to low-line males is not due to greater stimulation of circulating IGF-I by testosterone. Furthermore, testosterone does not appear to influence pubertal growth by acting on circulating levels of IGF-I.
一项研究旨在调查睾酮在调节基于血浆胰岛素样生长因子-I（IGF-I）进行差异选择品系的雄性小鼠生长及循环中IGF-I水平方面的作用。每个品系的对照组在10日龄时进行假手术，并从14日龄至70日龄用花生油处理。第二组在10日龄时进行去势，并从14日龄至70日龄用庚酸睾酮（0.5微克·（克体重）-1·天-1）处理，其体重与对照组无差异，但血浆IGF-I浓度较高。第三组将睾酮治疗推迟至42日龄，这延迟了生长，从35日龄至56日龄其体重显著低于其他两组。然而，该组的血浆IGF-I水平与对照组无差异。品系和处理的效应是相加的。得出的结论是，与低品系雄性相比，高品系雄性青春期生长更快并非由于睾酮对循环中IGF-I的更大刺激。此外，睾酮似乎并非通过作用于循环中的IGF-I水平来影响青春期生长。
