Effects of Protein Kinase Inhibitor, HA1077, on Intraocular Pressure and Outflow Facility in Rabbit Eyes

Abstract

To elucidate the roles of protein kinase in regulating the intraocular pressure (IOP) and outflow facility in rabbit eyes. Materials and Methods: A protein kinase inhibitor, 1-(5-isoquinolinesulfonyl)-homopiperazine (HA1077), was used. The IOP and the outflow facility were measured before and after topical, intracameral, or intravitreal administration of HA1077 in rabbits. Western blot analysis was performed to detect the 20-kd light chain of myosin in human trabecular meshwork (TM) cells and bovine ciliary muscle (CM) tissues. The cell morphologic condition and distribution of actin filaments and vinculin in TM cells were studied using cell biology techniques. Carbachol-induced contraction of isolated bovine CM strips following administration of HA1077 was examined in a perfusion chamber. Results: In rabbit eyes, the administration of HA1077 resulted in a significant decrease in IOP in a dosedependent manner. An increased outflow facility was also observed. Western blot analysis revealed the presence of 20-kd light chain of myosin in human TM cells and bovine CM tissues. In cultured human TM cells, exposure to HA1077 disrupted actin bundles and impaired focal adhesion formation. In addition HA1077 showed relaxation of bovine CM strips. Conclusions: Use of HA1077 caused a reduction in IOP and an increase in the outflow facility. The results of in vitro experiments suggest that the IOP-lowering effects of HA1077 may be related to the altered cellular behavior of TM cells and relaxation of CM contraction. The results of these studies suggested that protein kinase inhibitors have the potential to be developed into a treatment modality for glaucoma.

System for Rapid, Precise Modulation of Intraocular Pressure, toward Minimally-Invasive In Vivo Measurement of Intracranial Pressure

“…Outflow facility was measured as 0.085 ± 0.033 μL min -1 mmHg -1 in the first animal and 0.303 ± 0.098 μL min -1 mmHg -1 in the second ( n = 3 injections per animal; see also S4 Dataset ). Again, these measurements were reasonable in light of values reported in mice (0.0125 ± 0.0037 μL min -1 mmHg -1 , [ 30 , 34 ]) and rabbits (0.257 ± 0.055 μL min -1 mmHg -1 , [ 35 – 36 ])…”

System for Rapid, Precise Modulation of Intraocular Pressure, toward Minimally-Invasive In Vivo Measurement of Intracranial Pressure

“…Outflow facility was measured as 0.085 ± 0.033 μL min -1 mmHg -1 in the first animal and 0.303 ± 0.098 μL min -1 mmHg -1 in the second ( n = 3 injections per animal; see also S4 Dataset ). Again, these measurements were reasonable in light of values reported in mice (0.0125 ± 0.0037 μL min -1 mmHg -1 , [ 30 , 34 ]) and rabbits (0.257 ± 0.055 μL min -1 mmHg -1 , [ 35 – 36 ])…”

Effects of K-115 (Ripasudil), a novel ROCK inhibitor, on trabecular meshwork and Schlemm’s canal endothelial cells

“…Significant increases in outflow facility were observed after the instillation of K-115 at a concentration of 0.4%; however, we did not detect a significant effect of K-115 instillation on uveoscleral outflow or aqueous flow rate. These findings corroborate previous studies of other ROCK inhibitors, including Y-27632 and fasudil, in rabbits or monkeys 19 20 36 . These results strongly indicated that the ocular hypotensive effect of K-115 is potentiation of the outflow facility from the conventional outflow route.…”

“…Additionally, these effects were reversible. Similar effects have been reported for Y-27632 and fasudil 19 20 46 . Cytoskeletal changes are thought to induce retraction and rounding of cells and reduce actin bundles in response to ROCK inhibition by K-115 which may lead to reduced compaction of TM tissue and increased aqueous outflow 46 .…”

Effects of Rho Kinase Inhibitors on Intraocular Pressure and Aqueous Humor Dynamics in Nonhuman Primates and Rabbits

“…Significant findings were noted in aqueous flow, outflow facility, and uveoscleral outflow. Consistent with prior animal studies, 10,15,16,36–39 an increase in conventional outflow facility was demonstrated in the hypertensive eyes of NHPs after Rho kinase administration in this study.…”

System for Rapid, Precise Modulation of Intraocular Pressure, toward Minimally-Invasive In Vivo Measurement of Intracranial Pressure

“…Outflow facility was measured as 0.085 ± 0.033 μL min -1 mmHg -1 in the first animal and 0.303 ± 0.098 μL min -1 mmHg -1 in the second ( n = 3 injections per animal; see also S4 Dataset ). Again, these measurements were reasonable in light of values reported in mice (0.0125 ± 0.0037 μL min -1 mmHg -1 , [ 30 , 34 ]) and rabbits (0.257 ± 0.055 μL min -1 mmHg -1 , [ 35 – 36 ])…”

Effects of K-115 (Ripasudil), a novel ROCK inhibitor, on trabecular meshwork and Schlemm’s canal endothelial cells

“…Significant increases in outflow facility were observed after the instillation of K-115 at a concentration of 0.4%; however, we did not detect a significant effect of K-115 instillation on uveoscleral outflow or aqueous flow rate. These findings corroborate previous studies of other ROCK inhibitors, including Y-27632 and fasudil, in rabbits or monkeys 19 20 36 . These results strongly indicated that the ocular hypotensive effect of K-115 is potentiation of the outflow facility from the conventional outflow route.…”

“…Additionally, these effects were reversible. Similar effects have been reported for Y-27632 and fasudil 19 20 46 . Cytoskeletal changes are thought to induce retraction and rounding of cells and reduce actin bundles in response to ROCK inhibition by K-115 which may lead to reduced compaction of TM tissue and increased aqueous outflow 46 .…”

Effects of Rho Kinase Inhibitors on Intraocular Pressure and Aqueous Humor Dynamics in Nonhuman Primates and Rabbits

“…Significant findings were noted in aqueous flow, outflow facility, and uveoscleral outflow. Consistent with prior animal studies, 10,15,16,36–39 an increase in conventional outflow facility was demonstrated in the hypertensive eyes of NHPs after Rho kinase administration in this study.…”

System for Rapid, Precise Modulation of Intraocular Pressure, toward Minimally-Invasive In Vivo Measurement of Intracranial Pressure

“…Outflow facility was measured as 0.085 ± 0.033 μL min -1 mmHg -1 in the first animal and 0.303 ± 0.098 μL min -1 mmHg -1 in the second ( n = 3 injections per animal; see also S4 Dataset ). Again, these measurements were reasonable in light of values reported in mice (0.0125 ± 0.0037 μL min -1 mmHg -1 , [ 30 , 34 ]) and rabbits (0.257 ± 0.055 μL min -1 mmHg -1 , [ 35 – 36 ])…”

Effects of K-115 (Ripasudil), a novel ROCK inhibitor, on trabecular meshwork and Schlemm’s canal endothelial cells

“…Significant increases in outflow facility were observed after the instillation of K-115 at a concentration of 0.4%; however, we did not detect a significant effect of K-115 instillation on uveoscleral outflow or aqueous flow rate. These findings corroborate previous studies of other ROCK inhibitors, including Y-27632 and fasudil, in rabbits or monkeys 19 20 36 . These results strongly indicated that the ocular hypotensive effect of K-115 is potentiation of the outflow facility from the conventional outflow route.…”

“…Additionally, these effects were reversible. Similar effects have been reported for Y-27632 and fasudil 19 20 46 . Cytoskeletal changes are thought to induce retraction and rounding of cells and reduce actin bundles in response to ROCK inhibition by K-115 which may lead to reduced compaction of TM tissue and increased aqueous outflow 46 .…”

Effects of Rho Kinase Inhibitors on Intraocular Pressure and Aqueous Humor Dynamics in Nonhuman Primates and Rabbits

“…Significant findings were noted in aqueous flow, outflow facility, and uveoscleral outflow. Consistent with prior animal studies, 10,15,16,36–39 an increase in conventional outflow facility was demonstrated in the hypertensive eyes of NHPs after Rho kinase administration in this study.…”