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Vasoactive Intestinal Peptide (VIP) Inhibits Substrate Adherence Capacity of Rat Peritoneal Macrophages by a Mechanism That Involves cAMP

1993; Taylor & Francis; Volume: 1; Issue: 3 Linguagem: Inglês

10.3109/15419069309097255

2573-0029

Juan J. Segura‐Egea, Juan M. Guerrero, Miguel Angel López-González, Juan R. Calvo,

Diabetes Treatment and Management

In this study, vasoactive intestinal peptide (VIP) is shown to inhibit substrate adherence capacity of rat peritoneal macrophages. The inhibitory response occurred in the 0.1-1, 000 nM range of VIP concentrations and it was a time-dependent process. At 15 min, half maximal inhibition (ICw) was obtained at 0.37 ± 0.26 nM and maximal inhibition (53.8%) at 10−6 M VIP. The inhibitory effect of VIP was correlated with the stimulation by this peptide of cyclic AMP (cAMP) production in rat peritoneal macrophages. Moreover, agents that inhibited VIP-stimulated cAMP production, such as the VIP-antagonist [4-Cl-D-Phe6 Leu17]-VIP and somatostatin, also decreased the inhibitory effect of VIP on substrate adherence capacity of macrophages. On the contrary, the phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine (IBMX) and the lipid-soluble derivative of cAMP N6 2′-O-dibutyryl cAMP (Bu-cAMP) inhibited the adherence of macrophages to substrate and potentiated the inhibitory action of VIP. These results demonstrate that VIP inhibits substrate adherence capacity of rat peritoneal macrophages by a mechanism that involves cAMP, and show, for the first time, an action of VIP on the function of peritoneal macrophages.