Abstract

The acute toxic effects of orthochlorobenzylidene malononitrile (CS) on the rat testis were analyzed in terms of body weight, serum testosterone and histopathology of testis. The animal experiments were designed by intra-peritoneal injections of CS at 25 and 50% of lethal dose at 50% (LD₅₀) for 10 days. In three groups of 10 each Charles Foster rats, olive oil (0.5 ml), 10 and 20 mg/kg (in 0.5 ml olive oil) intra-peritoneal (ip) was daily administered, respectively (Groups A, B, and C) for 10 days. The rats were sacrificed on the 11^th day by cervical dislocation and blood and testes were collected for analysis. The results showed loss in body weight in Group C (20 mg/kg CS). A decline in testes weight of Groups B and C was noted. There is degeneration of testis and high cholesterol with low serum testosterone which suggested block of testosterone biosynthesis at Leydig cells in Group C. Group B showed partial testicular degeneration and no significant changes in serum testosterone levels. The low serum testosterone in Group C shows inhibition of spermatogenesis. This study is a first report on the acute toxicity of CS for rat testis by low testosterone level leading to inhibition of spermatogenesis.

Key words: Orthochlorobenzilidene malononitrile (CS), rat, testis.