Pituitary adenylate cyclase-activating polypeptide- and VIP-induced activation of adenylate cyclase in the porcine non-pigmented ciliary epithelium: effects of antagonists.
Vasoactive intestinal polypeptide (VIP) and two pituitary adenylate cyclase-activating polypeptides (PACAP-38 and PACAP-27) were investigated for their ability to activate the adenylate cyclase system in membrane preparations from the porcine non-pigmented ciliary epithelium (NPE). The NPE was dissociated from the adjacent pigmented ciliary epithelium of the iris-ciliary body (ICB) by incubation in low Ca2+ Ringer's solution. All three peptides caused a dose-dependent increase in cAMP formation in the NPE and the remaining part of the ICB. A VIP antagonist had a small effect on the dose-response curve for VIP, while the two PACAP fragments, PACAP(6-38) and PACAP(6-3 1), caused a rightward shift of the concentration response curves for PACAP-38, PACAP-27 and VIP. The results of the present study indicate that the non-pigmented ciliary epithelium of the porcine eye contain receptors for PACAP- and VIP-coupled to adenylate cyclase activation.
Samuelsson-Almén
M
M
Department of Physiology, University of Uppsala, Sweden.
Nilsson
S F
SF
D000262:Adenylyl Cyclases / Q000378:metabolism*; D000818:Animals; D002924:Ciliary Body / Q000187:drug effects / Q000201:enzymology*; D000242:Cyclic AMP / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004848:Epithelium / Q000187:drug effects / Q000201:enzymology; D007150:Immunohistochemistry; D066298:In Vitro Techniques; D009479:Neuropeptides / Q000145:classification / Q000494:pharmacology*; D010858:Pigmentation; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide; D013552:Swine; D014660:Vasoactive Intestinal Peptide / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D014665:Vasodilator Agents / Q000145:classification / Q000494:pharmacology*
D009479:Neuropeptides; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide; D014665:Vasodilator Agents; D014660:Vasoactive Intestinal Peptide; D000242:Cyclic AMP; D000262:Adenylyl Cyclases