Biomaterial Database

Characterization of ocular receptors for pituitary adenylate cyclase activating polypeptide (PACAP) and their coupling to adenylate cyclase. 1994

S F Nilsson, and P De Neef, and P Robberecht, and J Christophe

Department of Biochemistry and Nutrition, Université Libre de Bruxelles, Belgium.

Pituitary adenylate cyclase activating polypeptide (PACAP), a recently discovered neuropeptide, has large structural homology with vasoactive intestinal polypeptide (VIP). Two molecular forms exist, one with 27 (PACAP-27) and one with 38 (PACAP-38) amino acids. PACAP-27 is identical to the N-terminal of PACAP-38. Two major types of PACAP receptors have been identified; selective PACAP receptors, which bind PACAP with a much higher affinity than VIP, and non-selective VIP/PACAP receptors, which bind PACAP and VIP with equally high affinity. In the present investigation, PACAP receptors in different parts of the albino rabbit eye, and their coupling to adenylate cyclase were characterized. Crude tissue homogenates from iris, ciliary body, retina and choroid were used. Competition binding curves were established for VIP, PACAP-27 and PACAP-38, with [125I]VIP or [125I-Acetyl-His1]PACAP-27 as tracer. The effects on adenylate cyclase activity were determined by plotting dose-response curves (10(-10)-10(-6) M) for VIP, PACAP-27 and PACAP-38. The anterior uvea had mainly (approximately 80%) non-selective VIP/PACAP receptors, but a small amount of selective PACAP receptors was detected. In the retina, the selective PACAP receptor predominated (approximately 85%), while the choroid (including the retinal pigment epithelium) had approximately 60% selective PACAP receptors. PACAP-27 and PACAP-38 stimulated the formation of cAMP with the same efficacy: 6.9-fold in the ciliary body, 3.6-fold in the iris, 5.1-fold in the retina and 2.3-fold in the choroid.(ABSTRACT TRUNCATED AT 250 WORDS)

UI	MeSH Term	Description	Entries
D007457	Iodine Radioisotopes	Unstable isotopes of iodine that decay or disintegrate emitting radiation. I atoms with atomic weights 117-139, except I 127, are radioactive iodine isotopes.	Radioisotopes, Iodine
D007498	Iris	The most anterior portion of the uveal layer, separating the anterior chamber from the posterior. It consists of two layers - the stroma and the pigmented epithelium. Color of the iris depends on the amount of melanin in the stroma on reflection from the pigmented epithelium.
D009479	Neuropeptides	Peptides released by NEURONS as intercellular messengers. Many neuropeptides are also hormones released by non-neuronal cells.	Neuropeptide
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
D011979	Receptors, Pituitary Hormone	Cell surface proteins that bind pituitary hormones with high affinity and trigger intracellular changes influencing the behavior of cells. Since many pituitary hormones are also released by neurons as neurotransmitters, these receptors are also found in the nervous system.	Pituitary Hormone Receptors,Receptors, Pituitary Hormones,Pituitary Hormones Receptors
D012160	Retina	The ten-layered nervous tissue membrane of the eye. It is continuous with the OPTIC NERVE and receives images of external objects and transmits visual impulses to the brain. Its outer surface is in contact with the CHOROID and the inner surface with the VITREOUS BODY. The outer-most layer is pigmented, whereas the inner nine layers are transparent.	Ora Serrata
D002829	Choroid	The thin, highly vascular membrane covering most of the posterior of the eye between the RETINA and SCLERA.	Choriocapillaris,Haller Layer,Haller's Layer,Sattler Layer,Sattler's Layer,Choroids
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
D005123	Eye	The organ of sight constituting a pair of globular organs made up of a three-layered roughly spherical structure specialized for receiving and responding to light.	Eyes
D000242	Cyclic AMP	An adenine nucleotide containing one phosphate group which is esterified to both the 3'- and 5'-positions of the sugar moiety. It is a second messenger and a key intracellular regulator, functioning as a mediator of activity for a number of hormones, including epinephrine, glucagon, and ACTH.	Adenosine Cyclic 3',5'-Monophosphate,Adenosine Cyclic 3,5 Monophosphate,Adenosine Cyclic Monophosphate,Adenosine Cyclic-3',5'-Monophosphate,Cyclic AMP, (R)-Isomer,Cyclic AMP, Disodium Salt,Cyclic AMP, Monoammonium Salt,Cyclic AMP, Monopotassium Salt,Cyclic AMP, Monosodium Salt,Cyclic AMP, Sodium Salt,3',5'-Monophosphate, Adenosine Cyclic,AMP, Cyclic,Adenosine Cyclic 3',5' Monophosphate,Cyclic 3',5'-Monophosphate, Adenosine,Cyclic Monophosphate, Adenosine,Cyclic-3',5'-Monophosphate, Adenosine,Monophosphate, Adenosine Cyclic