Effects of fasting and refeeding on vasoactive intestinal peptide binding to rat blood mononuclear cells

The effect of acute and chronic starvation on vasoactive intestinal peptide (VIP) binding to rat blood mononuclear cells was studied. A short-term (1 day) fasting period did not induce significant changes in VIP binding. Longer periods of fasting (3 and 5 days) elicited an increase in VIP binding. This increase was due to an increase in affinity of both the high and the low affinity binding sites rather than to changes in binding capacity. Refeeding of fasted animals resulted in a decrease in VIP binding, reaching similar values to those of the control groups.