Effects of FSH administration during the neonatal period on adult sperm production in boars.

摘要

This study was designed to test the effects of neonatal FSH administration on sertoli cell mitosis and adult sperm production in boars. The treatment groups received 100mug/kg body weight of FSH (I.M.) every other day from either day 4-22 (early) or day 22-40 (late) after birth. Volumes of FSH were corrected weekly for increases in body weight. Four boars from each treatment group were castrated on days 21, 42, 98 and 330. The testes were evaluated for GATA-4 and PCNA activities and germ cell development. Blood samples were collected weekly through 9 weeks of age and then monthly after 59 weeks of age and evaluated for testosterone, estrogen, FSH, LH and IGF-1 concentrations. Four boars from each treatment group remained intact and were used for weekly semen collection until 77 weeks of age. Volume, concentration and total numbers of spermatozoa were recorded weekly and motility, mobility, and morphology analysis were performed monthly. All data was analyzed using SAS and proc GLM or proc Mixed, where appropriate. Boars in the early treatment group had an higher testosterone concentrations at 77 weeks of age compared to the late treated boars and the control boars (p&le0.0001). There were no differences among treatment groups in the mass of the seminiferous tubules (p=0.4055) or the number of sertoli cells per organ (p=0.7010). Only boars in the FSH treated groups had sertoli cells undergoing proliferation at day 98. The sperm concentration per ejaculate was higher for the early treatment group compared to controls or the late treatment group (p=0.06). The early treatment group also had increased numbers of primary spermatocytes as adults (p=0.0005). There were no effects of treatment on estimates of semen quality. Overall these results indicate that neonatal FSH treatment increased the length of time over which sertoli cell proliferation occurs during sexual maturation which resulted in an increase in the production of spermatozoa in adults.