Subacute toxicity of alpha-ergocryptine in Sprague-Dawley rats. 2: metabolic and hormonal changes

The present study describes the metabolic changes observed in a dietary sub acute toxicity experiment with the ergot alkaloid alpha-ergocryptine in Spr ague-Dawley rats. The observed effects on metabolic and hormonal parameters were described separately from the general toxicological effects, in, view of the important role of dopamine agonists in metabolism (e.g. ergot alkal oids in fescue toxicosis), The rats were fed 0, 4, 20, 100 or 500 mg ergocr yptine/kg diet for 28-32 days (equal to 0, 0.36, 1.7, 8.9 and 60 mg ergocry ptine/kg body weight/day for females and 0, 0.34, 1. 1, 6.6 and 44 mg ergoc ryptine/kg body weight/day for males). Total cholesterol and high-density l ipoprotein (HDL)-cholesterol were decreased dose dependently in females but the ratio HDL-cholesteral/total cholesterol was only decreased at 20 mg/kg body weight, Triglycerides and glucose concentrations were decreased in th e highest dose groups of both sexes. Serum urea concentrations were increas ed in the 20, 100 and 500 mg/kg dose groups. Insulin, glucagon and liver gl ycogen were increased in the highest dose group at the end of the study, wh en the animals were allowed to eat prior to blood sampling and necropsy. Pr olactin, T4 and FT4 were decreased in the 20, 100 and 500 mg/kg dose groups of both sexes. Follicle-stimulating hormone (FSH) was decreased in the 20, 100 and 500 mg/kg female dose groups and luteinizing hormone (LH) was incr eased in the 20, 100 and 500 mg/kg male dose groups. It is postulated that the observed effects on food intake, metabolism (lipid and carbohydrate) an d hormonal parameters are due to an interaction of ergocryptine with centra l dopaminergic activities, which comprise a major functional component of a central regulatory system for metabolism. (C) 2000 Elsevier Science Ltd. A ll rights reserved.