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

: 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.