Correlation between pituitary sialic acid and FSH concentrations during development, and after castration and testosterone treatment in the male rat

Abstract

The content and concentration of sialic acid (N-s Acetylneuraminic acid) and follicle stimulating hormone (FSH) in male rats have been estimated in the anterior pituitary gland during development (from ages 1 to 6 months), at different intervals after castration, and after castration followed by either testosterone propionate (TP) or diethylstilbestrol (DES) treatment. The concentration of sialic acid in the pituitary gland of young male rats is approximately 270 ± 10 μmoles per 100 g. This concentration rises to a peak value at the age of 60 days with a slight fall thereafter. In the adult castrated rats the concentration reaches a maximum of 324.24 μmoles at 21 days after surgery and is followed by an insignificant fall for up to 80 days. Although castration has been found to raise the pituitary sialic acid significantly, it remains unchanged after 200 μg or 2 mg of TP administered subcutaneously daily for 7 days to rats that have been castrated for 21 days. Administration of DES resulted in highly significant reductions in pituitary sialic acid levels in intact as well as in castrated male rats. Radioimmunoassay measurement of pituitary FSH under similar experimental conditions demonstrated a close correlation between FSH and sialic acid concentrations.