Biomaterial Database

Melatonergic involvement in diurnal changes of intraocular pressure in rabbit eyes. 1985

G C Chiou, and T Aimoto, and L Y Chiou

Endogenous biochemical regulation of diurnal changes in intraocular pressure was investigated in rabbits. Various biochemical parameters in eye tissues, particularly the iris and ciliary body, were studied at peak (21:00 hr) and trough (09:00 hr) points of IOP. No statistical difference in choline acetyltransferase activity, adrenergic transmitter levels and dopamine concentration could be detected at these points. On the other hand, serotonin N-acetyltransferase activity was significantly higher at 21:00 hr (2.84 +/- 0.14 nmoles/mg protein/hr) than at 09:00 hr (2.18 +/- 0.16 nmoles/mg protein/hr) indicating that melatonin might be involved in the diurnal changes in IOP. Intracameral injections of various agents into rabbit eyes revealed that melatonin but not serotonin nor N-acetylserotonin raised IOP markedly, indicating that melatonin but not its precursors is involved in IOP regulation. Topical application of melatonin did not affect the IOP presumably because it does not cross the cornea effectively.

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
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.
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
D002795	Choline O-Acetyltransferase	An enzyme that catalyzes the formation of acetylcholine from acetyl-CoA and choline. EC 2.3.1.6.	Choline Acetylase,Choline Acetyltransferase,Acetylase, Choline,Acetyltransferase, Choline,Choline O Acetyltransferase,O-Acetyltransferase, Choline
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
D000123	Acetyltransferases	Enzymes catalyzing the transfer of an acetyl group, usually from acetyl coenzyme A, to another compound. EC 2.3.1.	Acetyltransferase
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
D012701	Serotonin	A biochemical messenger and regulator, synthesized from the essential amino acid L-TRYPTOPHAN. In humans it is found primarily in the central nervous system, gastrointestinal tract, and blood platelets. Serotonin mediates several important physiological functions including neurotransmission, gastrointestinal motility, hemostasis, and cardiovascular integrity. Multiple receptor families (RECEPTORS, SEROTONIN) explain the broad physiological actions and distribution of this biochemical mediator.	5-HT,5-Hydroxytryptamine,3-(2-Aminoethyl)-1H-indol-5-ol,Enteramine,Hippophaine,Hydroxytryptamine,5 Hydroxytryptamine