Effect of latanoprost on regional blood flow and capillary permeability in the monkey eye.

Abstract

To evaluate the effects of latanoprost on regional blood flow and capillary permeability in the monkey eye. Anesthetized cynomolgus monkeys were unilaterally treated with a single dose containing 6 pg of latanoprost; or 10 microg of PhXA34 (13,14-dihydro-15R, S-17-phenyl-18,19,20-trinor-prostaglandin F2alpha [PGF2alpha]-isopropyl ester), which contains about 50% latanoprost. Regional blood flow in the eye was measured with radioactively labeled microspheres; capillary permeability was measured by determining the extravascular plasma-equivalent albumin space using 125I-albumin, 131I-albumin, and 51Cr-labeled erythrocytes. Latanoprost or PhXA34 had no or only a slight effect on the regional blood flow when measured 1, 2 1/2, 3, 4 1/2, and 6 hours after dose administration, with the exception of the anterior sclera, in which a moderate increase in blood flow was detected. No effect on capillary permeability to albumin was detected when studied 30 minutes to 2 1/2 hours and 5 to 6 hours after dose administration. Latanoprost, a selective prostaglandin F receptor agonist, exerted no or only slight vascular effects for up to 6 hours after dose administration in the monkey eye, with the exception of the anterior sclera, in which a moderate increase in blood flow was detected. Naturally occurring prostaglandins may cause marked microcirculatory changes in the eye that could be of clinical concern. Latanoprost, a selective prostaglandin F receptor agonist, seems to be devoid of such effects.