Alterations of the hormones follitropin and lutropin in the blood of young mice dosed with lindane

Abstract

Abstract Background The gonadotropins lutropin and follitropin stimulate steroid synthesis in the gonads during gonadal maturation by promoting oogenesis and spermatogenesis. Endocrine disruptors such as lindane (γHCH) can alter the reproductive stage so and could alter puberty by interfering with lutropin and follitropin signaling. γHCH was classified by World Health Organization as “moderately restricted”, and in 2009 it is production and agricultural use was prohibited, under the Stockholm Convention, however, its use as a pharmaceutical treatment against lice and scabies is still allowed (and mainly, for use by the health sector). This study aimed to examine the effects of single-dose exposure to γHCH in young mice (Mus musculus) on lutropin and follitropin concentration, and to correlate gonadal maturity status and phenotypic characteristics. Methods Young γHCH-treated mice (16 females and 16 males) received a single dose of 25, 10, 5, or 0 µg/ml γHCH per gram of body weight, ocular route. Once secondary sexual characteristics were observed, the gonads were dissected and examined using histological techniques and the ovarian follicles were classified as dependent and independent of gonadotropins; the testicles were classified as inactive, early and late spermatogenesis; and the blood was processed with the lutropin and follitropin ELISA kit. Results The results indicate significant differences in the concentration of lutropin and follitropin between males and females (Fisher p < 0.05). The lutropin and follitropin levels showed a tendency to decrease in females, whereas, in males they tended to increase as the dose of γHCH increased. In females, it was observed that at the follitropin and lutropin decreased 42.3% and 83.7%, respectively at dose of 25 µg/ml; while in males, follitropin increased 51.9% at the dose of 25 µg/ml, and at the dose of 10 µg/ml lutropin increased by 242.5%. Contrary to that, gonadal maturity increased in females and decreased in males with increasing γHCH dose, disagreeing with the idea that gonadotropins coincide with the onset of puberty and gonadal maturity. Conclusions The results allow us to infer that exposure to γHCH could promote non-monotonic responses; however, this does not seem to alter puberty in the doses and conditions of the present experiment.

Keywords

• Puberty
• Early puberty
• Mus musculus
• Endocrine disrupting chemical
• Gonadotropins