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Abstract #15518 Published in IGR 1-3
Quantitative autoradiographic visualization and pharmacology of FP-prostaglandin receptors in human eyes using the novel phosphor-imaging technology
Davis TL; Sharif NAJournal of Ocular Pharmacology and Therapeutics 1999; 15: 323-336
Quantitative autoradiographic visualization of FP prostaglandin receptors was determined in postmortem human eye sections using (3H)PGF2α and the novel phosphor-imaging technology coupled with computerized image analysis. Densitometric analysis of digital images obtained after a 19-day screen-exposure revealed FP receptors to be highly concentrated in the longitudinal ciliary muscle (12,741 digital light units (DLU/mm2)), iris sphincter muscle (19,261 DLU/mm2) and retina (9544 DLU/mm2), with lesser amounts (1558-3776 DLU/mm2) in five other ocular structures (n=3-4 donors). The highest percentage specific binding was in the iris sphincter and longitudinal ciliary muscle (78-73%) and lowest in the lens (12%). Binding of (3H)PGF2α to the longitudinal ciliary and iris sphincter muscles and retina was concentration-dependently and potently displaced by known FP-receptor-selective compounds such as cloprostenol (Ki = 13-37 nM), fluprostenol (Ki = 56-98 nM), PHXA85 (Ki = 181-206 nM) and latanoprost (isopropyl ester of PHXA85; Ki = 0.43-4.5 μm) (from up to four donor eyes). These quantitative phosphor-imaging autoradiography data provide further evidence for the presence of FP receptors in human longitudinal ciliary muscle, one of the tissues involved in the intraocular pressure lowering effects of FP-class prostaglandins. The quantitative localization of FP receptors in the human iris, iris sphincter muscle, and retina represent interesting new observations.
Dr. T.L. Davis, Molecular Pharmacology Unit, Alcon Laboratories, Inc., Fort Worth, TX 76134; USA
Classification:
11.4 Prostaglandins (Part of: 11 Medical treatment)
