Low dose 4-MBC effect on neuroendocrine regulation of reproductive axis in adult male rats

4-Methylbenzylidene camphor (4-MBC) is an ultraviolet absorbent. The objective of this paper was to evaluate the effect of 4-MBC low-dose exposure on the neuroendocrine reproductive regulation in male rats. Wistar male adult rats were injected sc. with 4-MBC during 5 days with a dose of 2 and 10 mg/kg or during 2 days with a dose of 2 and 20 mg/kg. In all rats serum prolactin, LH and FSH concentration were assayed. The hypothalamus of rats injected during 2 days were also dissected to study GnRH release. Rats that received 2 and 10 mg/kg of 4-MBC during 5 days showed a decrease in the LH and FSH serum concentration. In rats injected during 2 days, serum LH decreased with 2 and 20 mg/kg and FSH decreased with 2 mg/kg of 4-MBC. In vitro hypothalamic GnRH release also decreased in these animals. These results show that low doses of 4-MBC inhibit the reproductive axis in adult male rats.