Strain differences in pubertal development of male rats’ penile reflexes

Abstract

The penile reflexes in outbrcd Wistar, SD and inbred Fischer strain male rats aged from 23 to 62 days were observed for 15 min following sheath retraction. Plasma Luteinizing hormone (LH) and testosterone levels were measured at 23, 37, 51
and 70 days of age by RIA. All Wistar and SD rats displayed erection: cups and flips before plasma LH and testosterone levels peaked at 51 days of age, whereas in Fischer strain males, erections, flips, but not cups began to be seen around peak levels of these hormones at 51 days of age. The pubertal development of penile reflexes in Fischer strain males was slower than that in Wistar and SD Stocks. The present study is the first to clarify the strain differences in pubertal development of male rats‘ penile reflexes.