Effects of H-7 on the iris and ciliary muscle in monkeys.

PubMed ID: 9715688

Author(s): Tian B, Millar C, Kaufman PL, Bershadsky A, Becker E, Geiger B. Effects of H-7 on the iris and ciliary muscle in monkeys. Arch Ophthalmol. 1998 Aug;116(8):1070-7. PMID 9715688

Journal: Archives Of Ophthalmology (Chicago, Ill. : 1960), Volume 116, Issue 8, Aug 1998

OBJECTIVES To determine the effects of H-7 on (1) iris and ciliary muscles (CMs) in living monkeys; (2) isolated monkey CM strips; (3) actomyosin contractility in cultured Swiss 3T3 cells.

METHODS (1) Pupillary diameter (calipers) and accommodation (refractometer) in living monkeys were measured after topical, intracameral, or intravitreal administration of H-7 followed by systemic pilocarpine hydrochloride. (2) Pilocarpine-induced contraction of isolated monkey CM strips following administration of H-7 was measured in a perfusion chamber. (3) Actomyosin contractility in Swiss 3T3 cells cultured on thin silicone rubber film was determined by measuring cell-induced film wrinkles before and after administration of H-7.

RESULTS Topical H-7 prevented anesthesia-induced miosis but did not affect resting refraction. Intracameral or intravitreal H-7 dilated the pupil and inhibited miotic but not accommodative responses to pilocarpine. H-7 inhibited pilocarpine-induced contraction of isolated monkey CM strips and reduced Swiss 3T3 cell contraction.

CONCLUSIONS H-7 inhibits actin-based contractility in non-muscle cells and in monkey iris sphincter and CM. Under our in vivo experimental conditions, the effect on the iris predominates over that on the CM.