PROLACTIN TREATMENT INCREASES GLUT2 BUT NOT THE G-PROTEIN SUBUNIT CONTENT IN CELL-MEMBRANES FROM CULTURED NEONATAL RAT ISLETS

Neonatal rat islets exhibit a reduced secretory response to glucose, c ompared to adult rat islets. The maturation of the secretory response is stimulated by prolactin (PRL). We show here by immunoblot analysis that PRL increases the beta-cell/liver glucose transporter GLUT2 in me mbrane fractions from cultured neonatal rat islets. This increase (+ 8 6%) may explain, at least in part, the development of a mature glucose response. G proteins modulate insulin secretion from pancreatic beta- cells. We show here by immunoblot analysis that, in contrast to the ef fect on GLUT2, PRL treatment does not modify the G protein subunits al pha i2, alpha i3, alpha o, alpha s, alpha q and beta 35 and beta 36, i n cultured neonatal islets.