BimatoprostS1407

Bimatoprost mildly stimulates the rate of aqueous humor flow during the day (13%) and at night (14%), its ocular hypotensive action is due primarily to a 26% reduction in the tonographic resistance to outflow. Bimatoprost enhances the pressure-sensitive outflow pathway. ^[1] Bimatoprost displaces [³H]prostaglandin F(2alpha) from FP receptors with K(i) of 6.31 μM. Bimatoprost rapidly mobilizes intracellular Ca(2+) via cloned human FP receptors expressed in human embryonic kidney cells and via native FP receptors in 3T3 mouse fibroblasts with EC(50) of 2.94 μM and 2.2 μM. ^[2] Bimatoprost up-regulates Cyr61 mRNA expression in the cat iris. Bimatoprost-induced up-regulation of Cyr61 mRNA expression is not because of the activation of the prostaglandin FP receptor but a different receptor. ^[3] Bimatoprost consistently evokes responses in different cells within the same tissue preparation, whereas prostaglandin F(2 alpha) and 17-phenyl prostaglandin F(2 alpha) elicites signaling responses in the same cells. Bimatoprost selectively stimulates intracellular calcium signaling in different cat iris sphincter cells. ^[4]