Objectives: To determine the effects of the serine-threonine kinase inhibitor H-7 on (1) cell junctions and the attached actin-based cytoskeleton in cultured bovine aortic endothelial cells, and (2) outflow facility in living monkeys.
Methods: Bovine aortic endothelial cells were cultured by standard techniques. The architecture and distribution of actin filaments, vinculin, and beta-catenin in bovine aortic endothelial cells were studied by immunolabeling before and after exposure to H-7 at various concentrations and durations. Outflow facility (perfusion) and intraocular pressure (Goldmann tonometer) were determined before and after the intracameral or topical administration of H-7 or a vehicle.
Results: In bovine aortic endothelial cells, exposure to H-7 produced a reversible time- and concentration-dependent disruption of actin microfilaments and an alteration in the organization of cell-cell and cell-matrix adhesions. In monkeys, intracameral and topical administration of H-7 dose dependently and reversibly doubled facility, and topical H-7 reduced intraocular pressures.
Conclusion: H-7 increases outflow facility in monkeys, probably by inhibiting cell contractility, cytoskeletal support, and cell-cell adhesions in the trabecular meshwork.