EFFECTS OF HYPOPHYSECTOMY AND UROPHYSECTOMY ON WATER AND SODIUM TRANSPORT IN ISOLATED INTESTINE AND GILLS OF JAPANESE EEL (ANGUILLA JAPONICA)

Abstract

Effects of hypophysectomy and/or urophysectomy on the water transport in isolated intestines and on the sodium transport in isolated gills of sea-water adapted eels were examined. When isolated intestine was incubated in Ringer's solution, the net water flux across the intestinal wall of the eels, adapted to sea water, was greater than that of fresh-water eels. This increase in water flux in the intestines of sea-water eels was not observed when the hypophysis or the hypophysis and urophysis were removed together, but urophysectomy alone produced no significant change in the water flux. It is likely, therefore, that the hypophysis is involved in the observed increase in water flux. On the other hand, when isolated gills of the sea-water eels were incubated in sea water, the rate of penetration of sodium from surrounding sea water was smaller than that of the gills of freshwater eels. Hypophysectomy and/or urophysectomy had little effect on this adaptation process of the isolated gills.