OBJECTIVETo investigate the reduction of sperm motility in rats induced by vas-to-epididymis antidromic injection of 30% ethanol and its mechanism.

METHODSForty male adult Sprague-Dawley rats were randomized into 3 groups: bilateral vas injection (n = 15) , sham operation control (n = 15) and normal (n = 10). An aliquot of 0.5 ml of 30% ethanol was injected from vas to epididymis bilaterally. After 1 month, all the rats'vasa and epididymides were ablated for studies of the sperm motility, construction changes of the vas and contents of IL-6, IFN-gamma and carnitine of the epididymis.

RESULTSThere was markedly significant difference in sperm motility in the injection group (P < 0.01). The number of sperms in the bilateral vas injection group was 31, while in the sham operation control and normal groups was 64 and 68, respectively. The contents of IL-6 and IFN-gamma increased, and the carnitine reduced significantly (P < 0.05). However, no significant differences were noted between the control and the normal groups (P > 0.05). The contents of IL-6, IFN-gamma and carnitine in the bilateral vas injection group were 772.7 pg/ml, 350.7 pg/ml and 491.1 mol/L. But the same indexes in the sham operation and normal groups were 308.5 pg/ml, 172. 2 pg/ml and 664. 6 mol/L and 287. 8 pg/ml, 163. 8 pg/ml and 605.5 mol/L.

CONCLUSIONThe antidromic injection of ethanol from vas to epididymis can not only interfere the environment for sperm maturation but also activate the immunologic cells that secrete many cytokines (CK) in the genital system. All the factors can induce the reduction of sperm motility.