title: Melatonin potentiates tear secretion induced by diadenosine tetraphosphate in the rabbit.
abstract: Diadenosine tetraphosphate (Ap(4)A, 0.03 nmol) applied topically to the cornea of New Zealand white rabbits, evoked an increase in tear secretion of 9.7 +/- 2.60% (N=7). Melatonin (1 nmol) had no significant effect. Application of Ap(4)A in combination with melatonin, evoked a significantly greater increase in tear secretion of 34.2 +/- 5.8% (N=11). This potentiating effect of melatonin was blocked by pretreating the cornea with a topical application of the melatonin receptor antagonist, luzindole (240 nmol). Melatonin combined with Ap(4)A may be useful for treating dry eye conditions.
authors.affiliation: Institute of Medicine, Universiti Brunei Darussalam, Jalan Tungku Link, Gadong BE 1410, Brunei Darussalam. choyle@im.ubd.edu.bn
authors.forename: Charles H V
authors.initials: CH
authors.lastname: Hoyle
authors.forename: Assumpta
authors.initials: A
authors.lastname: Peral
authors.forename: Jesús
authors.initials: J
authors.lastname: Pintor
mesh_terms: D000818:Animals; D015226:Dinucleoside Phosphates / Q000008:administration & dosage / Q000494:pharmacology*; D004357:Drug Synergism; D008297:Male; D008550:Melatonin / Q000008:administration & dosage / Q000494:pharmacology*; D011817:Rabbits; D013666:Tears / Q000378:metabolism*; D014363:Tryptamines / Q000494:pharmacology
chemical_list: D015226:Dinucleoside Phosphates; D014363:Tryptamines; C057154:luzindole; C020733:diadenosine tetraphosphate; D008550:Melatonin