Pharmacological effects and lung-binding characteristics of a novel VIP analogue, [R15, 20, 21, L17]-VIP-GRR (IK312532).
ABSTRACT A novel VIP derivative, [R15, 20, 21, L17]-VIP-GRR (IK312532), relaxed potently the carbachol-induced contraction of guinea-pig isolated trachea with longer duration than that induced by VIP. IK312532 competed with [125I]VIP for the binding sites in the rat lung in a concentration-dependent manner. There was considerable decrease in specific [125I]VIP binding in each lobe of right and left lung 0.5 h after the intratracheal administration of IK312532 (50 microg/rat) as dry powder inhaler (DPI). Rosenthal analysis revealed that the administration of IK312532 (50 and 100 microg/rat)-DPI brought about a significant decrease of maximal number of binding sites (Bmax) for specific [125I]VIP binding in anterior and posterior lobes of rat right lung, suggesting a significant occupancy of lung VIP receptors. This effect by IK312532 in the posterior lobe of the right lung was dose-dependent and lasted until at least 2 h after the intratracheal administration. Furthermore, the antigen-evoked infiltration of granulocytes in the rat bronchiolar mucosa was markedly suppressed by the intratracheal administration of IK312532 (50 microg/rat)-DPI. In conclusion, the present study has shown that IK312532 exhibits long-lasting relaxation of tracheal smooth muscles and that the intratracheal administration of this peptide exerts a significant occupancy of lung VIP receptors as well as a suppression of the antigen-evoked infiltration of granulocytes in the bronchiolar mucosa. Thus, the formulation of IK312532 as DPI may be a pharmacologically useful drug delivery system for the therapy of pulmonary diseases such as asthma.
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ABSTRACT: Vasoactive intestinal peptide (VIP) was found to inhibit ovalbumin-induced histamine release from guinea-pig minced lung. Maximum inhibition occurred with a 10-20 min time of preincubation with VIP. Spontaneous histamine release was not altered by VIP. With 2 x 10(-6) M VIP, the dose-response curve to ovalbumin was shifted about 3-fold to the right, but the maximum histamine release was unaltered. Respiratory tract infection with parainfluenza 3 virus did not influence the inhibitory effect of VIP on histamine release.European Journal of Pharmacology 03/1983; 88(2-3):247-50. · 2.59 Impact Factor
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ABSTRACT: Vasoactive intestinal polypeptide (VIP) has a variety of physiological effects. Pharmacological evidence suggesting that VIP acts via multiple receptors has been confirmed by the cloning of two VIP receptors (VIP1 and VIP2) with very different amino acid sequences. At both the VIP1 and the VIP2 receptor VIP, PHI, PACAP38, and PACAP27 have similar potency to each other. Only the VIP1 receptor is activated by secretin. The messenger RNAs (mRNAs) for the two receptors have completely different distributions as mapped by in situ hybridization histochemistry. VIP1 receptor mRNA is predominantly found in the lung, small intestine, thymus, and within the brain in the cerebral cortex and hippocampus. VIP2 receptor mRNA is present in a number of areas where VIP acts but VIP1 receptor mRNA is not present, including the stomach and testes. In the CNS VIP2 receptor mRNA is exclusively present in areas associated with neuroendocrine function, including several hypothalamic nuclei. In the periphery, it is also present in the pituitary and in pancreatic islets.Endocrinology 01/1995; 135(6):2662-80. · 4.72 Impact Factor
- American Journal of Respiratory and Critical Care Medicine 06/2000; 161(5):1720-45. · 11.04 Impact Factor