VIP interaction with intestinal epithelial cells and liver plasma membranes from hepatectomized rats.

Specific binding of VIP and VIP-stimulated cyclic AMP accumulation were studied in jejuno-ileal (villous and crypt) and colonic epithelial cells three days after partial (70%) hepatectomy in the rat. The binding capacity (but not the affinity) of VIP receptors, and the efficiency (but not the potency) of VIP on cyclic AMP stimulation increased after hepatectomy (as compared to sham-operated rats). On the other hand, the affinity (but not the binding capacity) of VIP receptors in plasma membranes of the regenerating liver was decreased as compared to the control condition. The possibility that these findings may be related to an involvement of VIP in hepatic growth regulation deserves further investigation.