Intestinal Peptide

VIP is an amidated 28 amino acid peptide that was originally discovered in extracts of pig duodenum. Both VIP and its receptor have since been found in a wide variety of tissues, including those of the digestive system, the 

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Vasoactive Intestinal Peptide and Pituitary Adenylate Cyclase Activating Peptide. Vasoactive intestinal peptide (VIP)... 

USP (Sandostatiu) flutamide (Rulexin) [13311-84-7] C11H11F3N2O3 276.21 (66) tumors vasoactive intestinal peptide-secretory tumors metastatic prostatic stools vomit-ing abdomiaal pain pain on iujection diarrhea... 

Pituitary Adenylyl Cyclase-activating Polypeptide (PACAP) is a 38-amino acid peptide (PACAP-38), which is widely expressed in the central nervous system. PACAP is most abundant in the hypothalamus. It is also found in the gastrointestinal tract, the adrenal gland and in testis. Its central nervous system functions are ill-defined. In the periphery, PACAP has been shown to stimulate catecholamine secretion from the adrenal medulla and to regulate secretion from the pancreas. Three G-protein coupled receptors have been shown to respond to PACAP, PAQ (PACAP type I) specifically binds PACAP, VPACi and VPAC2 also bind vasoactive intestinal peptide (VDP). Activation of PACAP receptors results in a Gs-mediated activation of adenylyl cyclase. 

ATP with acetylcholine and vasoactive intestinal peptide in some parasympathetic nerves... 

Vasoactive Intestinal Peptide(VIP) is a 28-amino acid peptide, which has a variety of actions as a neuroendocrine hormone and a putative neurotransmitter. It... 

Brenneman DE, Westbrook GL, Fitzgerald SP, Ennist DL, Elkins KL, Ruff MR, Pert CB (1988) Neuronal cell killing by the envelope protein of HIV and its prevention by vasoactive intestinal peptide. Nature 335(6191) 639-642... 

Borchard, G. LueBen, H.L. deBoer, A. G. Verhoef, J. C. Lehr, C.-M. Junginger, H.E., The potential of mucoadhesive polymers in enhancing intestinal peptide drug absorption. Ill Effects of chitosan-glutamate and carbomer on epithelial tight junctions in vitro, j. Control. Rel. 39, 131-138 (1996). 

This was the original hypothesis put forward by Lee (1970) and expanded by Ogilvie et al. (1973). Secretory products of N. brasiliensis do indeed decrease the amplitude of contractions of segments of uninfected rat intestine maintained in an organ bath, but a role for AChE in this phenomenon was discounted due to the heat stability of the parasite factor, and the inability to duplicate the effect with AChE from the electric eel (Foster et al., 1994). Subsequent investigations demonstrated that the suppression of contraction could be duplicated by a 30-50 kDa fraction of secreted products, which contained a protein of 30 kDa that was immunologically cross-reactive with mammalian vasoactive intestinal peptide (VIP). Moreover, an antibody to porcine VIP significantly reduced the inhibitory effect of parasite-secreted products on contraction in vitro (Foster and Lee, 1996). 

Shepard, I. L. Jenkins, D. C. Duckworth, J. R. Sportsman et al. Association of intestinal peptide transport with a protein related to the cadherin superfamily, Science 1994, 264, 430-433... 

Guo, A., Hu, P., Balimane, P., Leibach, F. H., Sinko, P. J., Interactions of a nonpeptidic drug, valacyclovir, with the human intestinal peptide transporter (hPePTl) expressed in a mammalian cell line,... 

Wenzel, U., Gebert, I., Weintraut, H., Weber, W.-M., Clauss, W., Daniel, H., Transport characteristics of differently charged cephalosporin antibiotics in oocytes expressing the cloned intestinal peptide transporter PepTl and in human intestinal Caco-2 cells, J. Pharmacol. Exp. Ther. 1996, 277, 831-839. 

E. E., Tukker, J. J., Mapping the binding site of the small intestinal peptide carrier (PepTl) using comparative molecular field analysis, Receptors Channels 1998, 6, 189-200. 

Another type of intestinal peptide transporter, hPTl, which is significantly different in sequence from PEPT1, was identified using a functionally inhibitory monoclonal antibody [99]. This transporter is widely expressed in the human GI tract and facilitates the oral absorption of pdactam antibiotics and ACE inhibitors from the intestine [18, 99]. Interestingly, we recently reported that hPTl gene expression is approximately 4-fold higher than PEPT1 in the human duodenum [4] (Fig. 11.1). 

Yang, C. Y., A. H. Dantzig, and C. Pidgeon. Intestinal peptide transport systems and oral drug availability. Pharm. Res. 1999, 16, 1331-1343. 

Chen, H., et al. Molecular cloning and functional expression of a chicken intestinal peptide transporter (cPepTl) in Xenopus oocytes and Chinese hamster ovary cells. J. Nutr. 2002, 132, 387-393. 

Doring, F., S. Theis, and H. Daniel. Expression and functional characterization of the mammalian intestinal peptide transporter PepTl in the methylotropic yeast Pichia pastoris. Biochem. Biophys. Res. Commun. 1997, 232, 656-662. 

Wenzel, U., D. T. Thwaites, and H. Daniel. Stereoselective uptake of beta-lactam antibiotics by the intestinal peptide transporter. Br. ]. Pharmacol. 1995, 116, 3021-3027. 

Temple, C. S., et al. Peptide mimics as substrates for the intestinal peptide transporter. J. Biol. Chem. 1998, 273, 20-22. 

Walker, D., et al. Substrate upregula-tion of the human small intestinal peptide transporter, hPepTl. J. Physiol. 1998, 507, 697-706. 

Molecular determinants of recognition for the intestinal peptide carrier, J. Pharm. Sci. 1997, 86, 596-602. 

Swaan, P. W., Stenhouwer, M. C., Tukker, J., Molecular mechanism for the relative binding affinity to the intestinal peptide carrier. Comparison of three ACE-inhibitors enalapril, enalaprilat, and lisinopril, Biochim. Biophys. Acta 1995, 3236, 31-38. 

Danzig, A. H., Oral absorption of (S-lactams by intestinal peptide transport proteins, Adv. Drug Ddiv. Rev. 1997,... 

Friedrichsen, G. M., Nielsen, C. U., Steffansen, B., Begtrup, M., Model prodrugs designed for the intestinal peptide transporter. A synthetic approach for coupling of hydroxy-containing compounds to dipeptides, Eur. J. Pharm. Sci. 2001, 14, 13-19. 

Bai, J. P. F., pGlu-L-Dopa-Pro a tripeptider prodrug targeting the intestinal peptide transporter for absorption and tissue enzymes for conversation, Pharm. Res. 1995, 12, 1101-1104. 

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