Effect of cyclosporin A eyedrops on tear secretion in rabbit.
We investigated the tear secretion-stimulating effect of cyclosporin A (CyA) eyedrops in rabbits using Schirmer's method. The following findings were obtained: (1) CyA induced tear secretion in a concentration-dependent manner. CvA in 0.1% concentration showed the strongest effect in accelerating lacrimation, and this effect persisted from 3 to 8 hours after instillation. (2) CyA-induced lacrimation was inhibited by atropine sulfate, a muscarinic blocker. (3) CyA-induced lacrimation was also inhibited in a concentration-dependent manner by (D-Pro2, D-Trp7,9)-Substance P, which is a tachykinin-receptor-selective antagonist. (4) CyA-induced lacrimation was also inhibited by capsaicin, which is a stimulator that releases and depletes neurotransmitters from sensory nerve endings. We conclude from these pharmacological studies that, in the rabbit, CyA-induced tear secretion is mediated by both cholinergic and tachykinergic nerves.
Department of Ophthalmology, Juntendo University School of Medicine, Tokyo, Japan.
H
H
Toshida
K
K
Nakayasu
A
A
Kanai
D000818:Animals; D001285:Atropine / Q000008:administration & dosage / Q000494:pharmacology; D002211:Capsaicin / Q000008:administration & dosage / Q000494:pharmacology; D016572:Cyclosporine / Q000008:administration & dosage / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005260:Female; D005500:Follow-Up Studies; D017950:Ganglia, Sensory / Q000187:drug effects; D007166:Immunosuppressive Agents / Q000008:administration & dosage / Q000494:pharmacology*; D007765:Lacrimal Apparatus / Q000187:drug effects* / Q000294:innervation / Q000378:metabolism; D008297:Male; D018727:Muscarinic Antagonists / Q000008:administration & dosage / Q000494:pharmacology; D009883:Ophthalmic Solutions; D010275:Parasympathetic Nervous System / Q000187:drug effects; D011817:Rabbits; D018039:Receptors, Tachykinin / Q000037:antagonists & inhibitors; D013373:Substance P / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000494:pharmacology; D013666:Tears / Q000378:metabolism*
D007166:Immunosuppressive Agents; D018727:Muscarinic Antagonists; D009883:Ophthalmic Solutions; D018039:Receptors, Tachykinin; D013373:Substance P; D001285:Atropine; C032132:substance P, prolyl(2)-tryptophan(7,9)-; D016572:Cyclosporine; D002211:Capsaicin