猪性别畸形的发病机理

对一例雄性假两性畸形家猪进行了细胞遗传学、病理学和性激素及其受体的研究,应用放射免疫分析法测定了患猪60—80日龄时血浆睾酮和孕酮水平,以及静脉注射LH(200iu)后血浆睾酮浓度变化,还测定了性皮肤及子宫内膜的胞浆和胞核的二氢睾酮受体(DHTR)和雌二醇受体(ER),结果表明:在90日龄时性别畸形猪血浆中睾酮水平比雄猪低约50%,但在180日龄时接近雄猪水平,达92%,性畸形猪血中未测到孕酮,性皮肤组织的胞浆和胞核内DHTR含量均比雌雄对照猪低.胞浆中DHTR浓度为雄性对照动物的22.2%,为雌性对照的64%,胞核内分别为65%和56%,性畸形猪子宫组织中雌二醇受体(ER)较正常雌猪显著为低.本文讨论了该性别畸形猪的雌性性染色体与其睾丸发育的关系.其性皮肤中DHTR的浓度明显低下,是本病例具有雄性性腺,但未有雄性性器官发育的根本原因.

THE PATHOGENESIS OF SEX ABNORMALITY IN PIGS

The characteristics of cytogenetics, histopathology and sex steroids and the receptors of a male pseudohermaph rodite pig were studied. The levels of testosterone and estrogen in plasma during 60-80 days of age and the change in testosterone concentration in plasma after administration of LH ( 200iu ) were determined with RIA. And the dihydrotestosterone-receptor ( DHTR ) and estrogen-receptor ( ER ) in cytosol and nucleus of sex skin and the undeveloped uterus were also assayed. The results .showed that the testosterone level in plasma of the intersex pig was about 50% lower than that of the normal male group at the age of 90 days. At the age of 180 days,however, the Tlevel increased to 92% that of the normal male group. No significant concentration of progesterone was detected. The result of receptor assay showed that the DHTR concentration in cytosol and nucleus of sex skin of the intersex pig were lower significantly than those of both the normal male and female groups. In cytosol it was 22.2% the amount in the normal male group and 62% the amount in the normal female group, in the nucleeu it was 65% and 56% respectively. Compared with the uterus of the normal female group, significant variation of estrogen-recep-tor(ER ) concentration in undeveloped uterus of the intersex pig was found.The relationship between the presence of female sex chromosome complement and the development of testis is discussed. And the endocrinological results suggested that the low concentration of DHTR in sex skin is responsible for-the failure of masculinization of the genital tract in the intersex Pig.