Biomaterial Database

The role of calcium in the regulation of melatonin biosynthesis in the retina. 1992

J B Zawilska

Department of Pharmacodynamics, Medical University, Lódź, Poland.

Vertebrate retina rhythmically produces melatonin, a hormone involved in the regulation of several intraocular processes cued by environmental lighting conditions. Calcium ions play an important role in the induction process of serotonin N-acetyltransferase (NAT), a key regulatory enzyme in melatonin biosynthetic pathway. The physiological, i.e. nocturnal, increase of NAT activity in the retina depends on transmembrane transport of Ca2+ through the L-type of voltage-sensitive calcium channels. It is suggested that Ca2+ may regulate NAT activity indirectly, by affecting the intracellular cyclic AMP content, which is, in turn, critical in the regulation of melatonin biosynthesis. The mode and mechanisms of Ca2+ action on processes governing melatonin formation in the retina are discussed.

UI	MeSH Term	Description	Entries
D008550	Melatonin	A biogenic amine that is found in animals and plants. In mammals, melatonin is produced by the PINEAL GLAND. Its secretion increases in darkness and decreases during exposure to light. Melatonin is implicated in the regulation of SLEEP, mood, and REPRODUCTION. Melatonin is also an effective antioxidant.
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
D002118	Calcium	A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.	Coagulation Factor IV,Factor IV,Blood Coagulation Factor IV,Calcium-40,Calcium 40,Factor IV, Coagulation
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
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