system
Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: OBJECTIVE, METHODS, RESULTS. Meshes: Animals, Dose-Response Relationship, Drug, Enzyme Inhibitors, Iris, Muscle Contraction, Muscle, Smooth, Myosin-Light-Chain Phosphatase, Parasympathetic Nervous System, Protein Kinase C, Pupil, Swine, rho-Associated Kinases.
user
Is rho-kinase , but not protein kinase C , involved in generation of the spontaneous tone in the resting phase of the isolated pig iris sphincter muscle? Context: The purpose of the present study was to clarify the role of Rho-kinase and/or protein kinase C in the resting tension of the isolated pig iris sphincter muscle. The motor activity of the isolated pig iris sphincter muscle was measured isometrically. EGTA, a chelator of extracellular Ca(2+), significantly reduced the resting tension. Y27632, a Rho-kinase inhibitor, significantly reduced the resting tension in a concentration-dependent manner. The resting tension diminished by Y27632 was significantly recovered by the addition of calyculin A, a myosin light chain phosphatase (MLCP) inhibitor, in a concentration-dependent manner. GF109203X, a protein kinase C inhibitor, had no effect on the resting tension.
assistant
These results suggest that, in the isolated pig iris sphincter muscle, Rho-kinase plays an important role in the generation of spontaneous tone in the resting phase via the inhibition of MLCP activity. Final Decision: yes