Biomaterial Database

Enkephalin, neurotensin and somatostatin increase cAMP levels in the chicken retina. 1998

S I Firth, and M K Boelen, and I G Morgan

La Trobe University, Bendigo, Victoria, Australia. s.firth@bendigo.latrobe.edu.au

OBJECTIVE Enkephalin, neurotensin and somatostatin are released at high rates in the dark and at low rates in the light n the chicken retina. The present study examines the effects of these peptide transmitters on retinal cAMP METHODS: Chicken retinas were incubated in vitro with various drugs for 10min. Cyclic AMP was extracted with acidified ethanol and retinal levels of cAMP were measured using a radioassay kit. CONCLUSIONS These peptides increased cAMP levels in the chicken retina in vitro, which is surprising as their receptors are generally thought to be negatively coupled to adenylate cyclase. The paradoxical increase in retinal cAMP may be due to unique types of peptide receptors that are positively coupled to adenylate cyclase. A more plausible explanation is that these peptides act indirectly and change the rate of release of another transmitter, whose receptor is coupled to adenylate cyclase.

UI	MeSH Term	Description	Entries
D009496	Neurotensin	A biologically active tridecapeptide isolated from the hypothalamus. It has been shown to induce hypotension in the rat, to stimulate contraction of guinea pig ileum and rat uterus, and to cause relaxation of rat duodenum. There is also evidence that it acts as both a peripheral and a central nervous system neurotransmitter.
D009924	Organ Culture Techniques	A technique for maintenance or growth of animal organs in vitro. It refers to three-dimensional cultures of undisaggregated tissue retaining some or all of the histological features of the tissue in vivo. (Freshney, Culture of Animal Cells, 3d ed, p1)	Organ Culture,Culture Technique, Organ,Culture Techniques, Organ,Organ Culture Technique,Organ Cultures
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
D002645	Chickens	Common name for the species Gallus gallus, the domestic fowl, in the family Phasianidae, order GALLIFORMES. It is descended from the red jungle fowl of SOUTHEAST ASIA.	Gallus gallus,Gallus domesticus,Gallus gallus domesticus,Chicken
D004745	Enkephalins	One of the three major families of endogenous opioid peptides. The enkephalins are pentapeptides that are widespread in the central and peripheral nervous systems and in the adrenal medulla.	Enkephalin
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
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D013004	Somatostatin	A 14-amino acid peptide named for its ability to inhibit pituitary GROWTH HORMONE release, also called somatotropin release-inhibiting factor. It is expressed in the central and peripheral nervous systems, the gut, and other organs. SRIF can also inhibit the release of THYROID-STIMULATING HORMONE; PROLACTIN; INSULIN; and GLUCAGON besides acting as a neurotransmitter and neuromodulator. In a number of species including humans, there is an additional form of somatostatin, SRIF-28 with a 14-amino acid extension at the N-terminal.	Cyclic Somatostatin,Somatostatin-14,Somatotropin Release-Inhibiting Hormone,SRIH-14,Somatofalk,Somatostatin, Cyclic,Somatotropin Release-Inhibiting Factor,Stilamin,Somatostatin 14,Somatotropin Release Inhibiting Factor,Somatotropin Release Inhibiting Hormone