in order to determine whether the gonadal and hypophyseal modes of regulation recently reported for the microsomal enzymes of hepatic steroid metabolism are also valid for cytoplasmic enzymes , three enzymes whose activities exhibit sex differences ( male : female activity ratio shown in brackets ) , 5beta-reductase ( 1.7:1 ) , 20alpha-hydroxysteroid dehydrogenase ( 5 : 1 ) and 17beta-hydroxysteroid dehydrogenase ( 4:1 ) , as well as one enzyme whose activity shows no sex difference , 3beta-hydroxy-delta5-steroid dehydrogenase , were investigated after various interferences with the endocrine balance ( gonadectomy , hypophysectomy , combination of both operations , administration of testosterone or oestradiol ) .
C0014136
endocrine
C0020632
hypophysectomy