Leptin Adversely Affects The Transition of Histone-to-Protamine during Spermatogenesis in Sprague-Dawley Rats

Abstract

The aim of this study was to examine the effect of leptin on the histone to protamine ratio in adult rat sperm. Twelve-week old Sprague-Dawley rats were randomized into control and leptin-treated groups with 6 rats per group.  Leptin-treated group received intra-peritoneal injections (i.p.) of leptin daily for 42 days (60 µg/kg body weight).  Control rats received 0.1 ml of 0.9 % saline i.p. for 42 days.  Upon completion of the treatment sperm count, morphology and histone-to-protamine ratio measurements were performed.  Gene expressions of HAT, HDAC1, HDAC2, H2B, H2A, H1, PRM1, PRM2, TNP1 and TNP2 were analyzed using microarray analyses.  Data were analyzed using ANOVA.   The results showed that, sperm count was significantly lower among leptin-treated rats compared to control one, whereas the fraction of sperm with abnormal morphology, the histone-to-protamine ratio and the expressions of HAT, HDAC1, HDAC2, H2B, H2A, H1, PRM1 were significantly higher in leptin treated rats.  As a conclusion, exogenous leptin administration adversely affects sperm count and morphology, which might be related to alteration in the histone-to-protamine transition during spermatogenesis.