Characterization of the mechanism of acute ocular irritation to YAG laser capsulotomy in rabbits: effects of substance P antagonists, Met-enkephalin, tetracaine and tetrodotoxin.
This study was undertaken to characterize the mechanism of ocular irritation to YAG laser capsulotomy in rabbits. The blocking agents were administered intravitreally. (D-Arg1,D-Pro2,D-Trp7,9)-SP, a substance P antagonist, tended to reduce miosis but had no effect on intraocular pressure (IOP). It had less effect on miosis than (D-Arg1,D-Pro2,D-Trp7,9,Leu11)-SP another SP antagonist. Met-enkephalin and tetracaine had no effect on miosis or the increase in IOP after YAG laser capsulotomy, whereas tetrodotoxin reduced miosis, but had no clear-cut effect on IOP, or the increase in aqueous humor protein concentration. This indicates an involvement of sensory neurons with release of SP or a closely related peptide in the miotic component part while the increase in IOP and the barrier breakdown probably are dependent mainly on a release of prostaglandins.
Oksala
O
O
Research Department of Pharmaceutical Company Oy Star Ab, Tampere, Finland.
Stjernschantz
J
J
von Dickhoff
K
K
D000818:Animals; D004744:Enkephalin, Methionine / Q000494:pharmacology; D005136:Eye Proteins / Q000378:metabolism; D005260:Female; D007429:Intraocular Pressure / Q000187:drug effects; D053685:Laser Therapy / Q000009:adverse effects*; D007903:Lens Capsule, Crystalline / Q000187:drug effects / Q000601:surgery*; D007908:Lens, Crystalline / Q000601:surgery*; D008297:Male; D015877:Miosis / Q000188:drug therapy / Q000209:etiology; D009431:Neural Conduction / Q000187:drug effects; D011817:Rabbits; D011994:Recombinant Proteins; D013373:Substance P / Q000031:analogs & derivatives / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D013748:Tetracaine / Q000494:pharmacology; D013779:Tetrodotoxin / Q000494:pharmacology; D013997:Time Factors
D005136:Eye Proteins; D011994:Recombinant Proteins; D013748:Tetracaine; D013373:Substance P; D013779:Tetrodotoxin; D004744:Enkephalin, Methionine; C050702:substance P, Arg(1)-Pro(2)-Trp(7,9)-Leu(11)-; C062159:substance P, Arg(1)-Pro(2)-Trp(7,9)-