Variations in serum LH and FSH during the post natal period of guinea pigs

: LH and FSH are measured by radio-immunoassays in sera of young male guinea Pigs and of females, whose ages range from some hours to 23 days. The curves for the two gonadotropins are not superimposable and are not the same in the two sexes. High concentrations of LH are observed in 8 to 9 day old males; in females, high concentrations of FSH are observed just after the birth and from the 7th to the 10th as well. These facts suggest a dual control of FSH and LH secretion in the guinea pig.