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Abstract #6673 Published in IGR 4-1

Pharmacological effects of latanoprost prostaglandin E2, and F on isolated rabbit ciliary artery

Ishikawa H; Yoshitoma T; Mashimo K; Nakanishi M; Shimizu K
Graefe's Archive for Clinical and Experimental Ophthalmology 2002; 240: 120-125


BACKGROUND: Latanoprost is a prostaglandin (PG)F analogue widely recognized in the treatment of glaucoma. To investigate the action of this drug on the ocular circulation, the authors studied its effects on isolated rabbit ciliary artery. The data obtained on this drug are compared with the data from PGE2 and PGF. METHODS: Under the microscope, ciliary artery specimens were prepared from rabbit eyes and mounted in a myograph system. The effects of latanoprost, PGE2, and PGF on the isolated rabbit ciliary artery were investigated in vitro using isometric tension recording methods. RESULTS: Exogenously applied PGF, but not latanoprost, evoked contraction in the rabbit ciliary artery. After precontraction with excess-[K]0 solution, latanoprost evoked relaxation dose-dependently. Latanoprost, at a concentration of 100 μm, induced maximum relaxation, which was not blocked by 10 μm L-nitro-L-arginine methylester (L-NAME), 1 μm 8-37 calcitonin gene-related peptide (CGRP), or 10 μm indomethacin. Moreover, latanoprost induced relaxation even in preparations without endothelium. The maximum relaxation obtained with PGE2 was somewhat less than 50% of that with latanoprost. CONCLUSIONS: These results indicate that latanoprost and PGE2 relaxed rabbit ciliary artery to different degrees. The relaxation provoked by latanaprost was not dependent on endothelium and was not caused by intrinsic PG, CGRP, or nitric oxide. The mechanism of this relaxation is not yet clear.

Dr. H. Ishikawa, Department of Ophthalmology, Kitasato University, 1-15-1 Kitasato, Sagamihara, Kanagawa 228, Japan. hitoshi@cx.airnet.ne.jp


Classification:

5 Experimental glaucoma; animal models
6.11 Bloodflow measurements (Part of: 6 Clinical examination methods)
11.4 Prostaglandins (Part of: 11 Medical treatment)



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