Plasma Calcium, Phosphate and Magnesium Levels of the Freshwater Male Stinging Catfish, Heteropneustes fossilis in Response to Hypophysectomy and Replacement Therapy with Prolactin

Abstract

Hypophysectomy was performed on freshwater male stinging catfish, Heteropneustes fossilis. Prolactin (0.1 mg/100 g bw/day) was administered to the hypophysectomized fish for 10 days. The plasma calcium, phosphate and magnesium levels were determined on day 1, 3, 5 and 10. Hypophysectomy provoked hypocalcemia and hypophosphatemia whereas the plasma magnesium levels were not significantly altered. Administration of prolactin to hypophyesctomized fish elevated the levels of these electrolytes. These results indicate that prolactin may be involved in the regulation of calcium, phosphate and magnesium in fish.