Some Biochemical and Histological Changes during Experimentally Induced Hyperprolactinemia in Male Rabbits

Abstract

SummaryDetermination of the effect of prolactin administration on glucose, non-esterified fatty acids, insulin, and liver glycogen concentrations in male rabbit was the aim of the present investigation. Over-secretion of prolactin has been found to be one of the most important causes of male infertility in humans [l, 2] and animals [3,4]. Very little however has been published about the effects of prolactin on carbohydrate metabolism. However, it was reported that lipid abnormalities were most common in infertile men [5]. It was suggested that non-esterified fatty acid (NEFA) level exerts a direct action at the testicular function in man [6]. It was therefore of interest to study the metabolic effect of prolactin on the levels of glucose, NEFA, and insulin in serum and glycogen concentration in liver. This necessiated the establishment of the effect of prolactin administration on the liver and testis and to find to what extent prolactin was responsible for the hepatic and testicular functions in male rabbits.

Hyperglycemic Effect of Prolactin in Anterior Pituitary Transplanted Rats.

“…A similar trend in maintaining a higher prolactin concentration after 90 days of transplantation has been suggested (Tresgueres et al, 1981;Esquifino et al, 1984) and hyperprolactinemia with pituitary transplantation can be maintained for 15 months (Esquifino et al, 1984). However, hyperprolactinaemia was not found to modify serum insulin at basal or at different durations of study, as reported earlier (Adler and Sokol, 1982;Yousef et al, 1988).…”

“…Landgraf et al, (1977) called prolactin a 'diabetogenic' hormone and a considerable number of reports suggest an anti-insulin effect exerted by prolactin especially on carbohydrate metabolism in various species (Sinkoff and debodo, 1953;debodo and Altszuler, 1958;Manns and Boda, 1965;McGarry and Beck, 1972;Rathgeb et al, 1971;Yousef et al, 1988). In most of the studies, acute hyperprolactinemia was maintained by the administration of ovine prolactin for different durations (Manns and Boda, 1965;Rathgeb et al, 1971;Yousef et al, 1988).…”