Biomaterial Database

Vasoactive intestinal peptide and intraocular pressure: adenylate cyclase activation and binding sites for vasoactive intestinal peptide in membranes of ocular ciliary processes. 1987

T W Mittag, and A Tormay, and S M Podos

Vasoactive intestinal peptide (VIP)-responsive adenylate cyclase and VIP binding sites were investigated in membranes prepared from ciliary processes dissected from albino rabbit eyes. High-affinity binding sites for VIP (Kd, 0.95 nM; 607 fmol/mg of protein), in addition to beta adrenergic sites labeled by dihydroalprenolol (Kd, 0.48 nM; 123 fmol/mg of protein), were present. Activation of adenylate cyclase by VIP had a Ka of 65 nM, and the maximal response was 3.3-fold greater than that for I-isoproterenol (Ka, 102 nM). A peptide fragment of VIP (sequence 10-28) was inactive in all assays and did not inhibit VIP-stimulated adenylate cyclase at 10 microM. Responses to VIP and isoproterenol in combination were additive at lower doses but less than additive at maximal doses. Responses to VIP in combination with a low dose of forskolin (0.1 microM) were potentiated at all dose levels, whether assays were done in presence of MgCl2 or MnCl2. VIP- and forskolin-activated adenylate cyclase was associated with the nonpigmented epithelial cell fraction and not with pigmented epithelial cells separated on Percoll density gradients after dissociation of cells from processes by collagenase digestion. Intravitreous injection of 10 nmol of VIP into the rabbit eye caused a maximal reduction in intraocular pressure at 40 to 50 hr lasting beyond 72 hr. VIP-responsive and beta adrenergic-responsive adenylate cyclase are present on the same cell type (nonpigmented epithelial cells) and appear to share components of the adenylate cyclase system in the same membrane. VIP may participate in the physiologic regulation of aqueous humor secretion at the level of the epithelial cell membrane.

UI	MeSH Term	Description	Entries
D007429	Intraocular Pressure	The pressure of the fluids in the eye.	Ocular Tension,Intraocular Pressures,Ocular Tensions,Pressure, Intraocular,Pressures, Intraocular,Tension, Ocular,Tensions, Ocular
D007545	Isoproterenol	Isopropyl analog of EPINEPHRINE; beta-sympathomimetic that acts on the heart, bronchi, skeletal muscle, alimentary tract, etc. It is used mainly as bronchodilator and heart stimulant.	Isoprenaline,Isopropylarterenol,4-(1-Hydroxy-2-((1-methylethyl)amino)ethyl)-1,2-benzenediol,Euspiran,Isadrin,Isadrine,Isopropyl Noradrenaline,Isopropylnoradrenaline,Isopropylnorepinephrine,Isoproterenol Hydrochloride,Isoproterenol Sulfate,Isuprel,Izadrin,Norisodrine,Novodrin,Hydrochloride, Isoproterenol,Noradrenaline, Isopropyl,Sulfate, Isoproterenol
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008566	Membranes	Thin layers of tissue which cover parts of the body, separate adjacent cavities, or connect adjacent structures.	Membrane Tissue,Membrane,Membrane Tissues,Tissue, Membrane,Tissues, Membrane
D011817	Rabbits	A burrowing plant-eating mammal with hind limbs that are longer than its fore limbs. It belongs to the family Leporidae of the order Lagomorpha, and in contrast to hares, possesses 22 instead of 24 pairs of chromosomes.	Belgian Hare,New Zealand Rabbit,New Zealand Rabbits,New Zealand White Rabbit,Rabbit,Rabbit, Domestic,Chinchilla Rabbits,NZW Rabbits,New Zealand White Rabbits,Oryctolagus cuniculus,Chinchilla Rabbit,Domestic Rabbit,Domestic Rabbits,Hare, Belgian,NZW Rabbit,Rabbit, Chinchilla,Rabbit, NZW,Rabbit, New Zealand,Rabbits, Chinchilla,Rabbits, Domestic,Rabbits, NZW,Rabbits, New Zealand,Zealand Rabbit, New,Zealand Rabbits, New,cuniculus, Oryctolagus
D011964	Receptors, Gastrointestinal Hormone	Cell surface proteins that bind gastrointestinal hormones with high affinity and trigger intracellular changes influencing the behavior of cells. Most gastrointestinal hormones also act as neurotransmitters so these receptors are also present in the central and peripheral nervous systems.	Gastrointestinal Hormone Receptors,Intestinal Hormone Receptors,Receptors, Gastrointestinal Peptides,Gastrointestinal Hormone Receptor,Intestinal Hormone Receptor,Receptors, Gastrointestinal Hormones,Receptors, Intestinal Hormone,Gastrointestinal Hormones Receptors,Gastrointestinal Peptides Receptors,Hormone Receptor, Gastrointestinal,Hormone Receptor, Intestinal,Hormone Receptors, Gastrointestinal,Hormone Receptors, Intestinal,Hormones Receptors, Gastrointestinal,Peptides Receptors, Gastrointestinal,Receptor, Gastrointestinal Hormone,Receptor, Intestinal Hormone
D002924	Ciliary Body	A ring of tissue extending from the scleral spur to the ora serrata of the RETINA. It consists of the uveal portion and the epithelial portion. The ciliary muscle is in the uveal portion and the ciliary processes are in the epithelial portion.	Corpus Ciliare,Corpus Ciliaris,Bodies, Ciliary,Body, Ciliary,Ciliare, Corpus,Ciliares, Corpus,Ciliari, Corpus,Ciliaris, Corpus,Ciliary Bodies,Corpus Ciliares,Corpus Ciliari
D004305	Dose-Response Relationship, Drug	The relationship between the dose of an administered drug and the response of the organism to the drug.	Dose Response Relationship, Drug,Dose-Response Relationships, Drug,Drug Dose-Response Relationship,Drug Dose-Response Relationships,Relationship, Drug Dose-Response,Relationships, Drug Dose-Response
D004789	Enzyme Activation	Conversion of an inactive form of an enzyme to one possessing metabolic activity. It includes 1, activation by ions (activators); 2, activation by cofactors (coenzymes); and 3, conversion of an enzyme precursor (proenzyme or zymogen) to an active enzyme.	Activation, Enzyme,Activations, Enzyme,Enzyme Activations
D000262	Adenylyl Cyclases	Enzymes of the lyase class that catalyze the formation of CYCLIC AMP and pyrophosphate from ATP.	Adenyl Cyclase,Adenylate Cyclase,3',5'-cyclic AMP Synthetase,Adenylyl Cyclase,3',5' cyclic AMP Synthetase,AMP Synthetase, 3',5'-cyclic,Cyclase, Adenyl,Cyclase, Adenylate,Cyclase, Adenylyl,Cyclases, Adenylyl,Synthetase, 3',5'-cyclic AMP