Abstract: 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.

Key words: sex abnormality, pig, testosterone, estrogen, receptor