Temporal Distribution of Serum Levels of LH and FSH in Adult Male Golden Hamsters Exposed to Long or Short Days

Abstract

Serum levels of LH and FSH were measured at 4-h intervals over a 24-h time period in adult male hamsters either maintained on photostimulatory long days (LD 14:10) or exposed to a nonstimulatory photoperiod (LD 6:18) for 60 days. Regardless of the time of day animals were sacrificed, serum gonadotropin levels were always high in hamsters maintained on LD 14:10 than in animals maintained on LD 6:18.