Abstract
In the present study, we have examined the effect of guanine nucleotides on VIP binding to rat peritoneal macrophage membranes. Both guanosine 5′-triphosphate (GTP) and its nonhydrolizable analog guanosine 5′-β, Y-imidotriphosphate [Gpp(NH)p] inhibited, in a dose-dependent manner, the VIP binding to its specific binding sites. Half-maximal inhibition (IC 50) was observed at 5.4 ± 0.5 μM GTP. The inhibitory effect of GTP was due to an increase of the dissociation rate of peptide bound to membranes. The specificity of the binding inhibition was assessed from the lack of action of the other nucleotides tested. These results directly suggest the coupling of VIP binding sites with guanine nucleotide binding proteins in rat peritoneal macrophage membranes.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
