Neuroendocrine and reproductive effects of contemporary-use pesticides

Work in our laboratory has focused on the hypothesis that certain environmental contaminants will interfere with reproductive function because they disrupt the neuroendocrine regulation of gonadal function. In this article, we review the evidence that certain classes of contemporary-use pesticides alter gonadotropin secretion through a disruption of hypothalamic mechanisms. Specifically, we discuss the effect of formamidine and dithiocarbamate pesticides on the noradrenergic control of pituitary hormone secretion, ovarian function, and pregnancy in the rat. This is followed by a review of studies evaluating the effect of a chlorotriazine herbicide, atrazine, on the hormonal control of ovulation and lactation. We also discuss the physiological consequences of these endocrine alterations in the female, how toxicant-induced endocrine alterations may differ in physiological outcome in the male and female, and the fact that the reproductive risk assessment of some pesticides that act on the central nervous system (CNS) may be influenced by the development of tolerance.