ROCK ACTIVITY ON THE TEMPERATURE-DEPENDENT RESPONSES OF CALF CARDIAC VEIN
B. Ramya Sree
Department of Biotechnology, Sree Vidyanikethan Engineering College, Tirupati
Jyothi M. Joy
Department of Pharmacognosy, Sree Vidyanikethan College of Pharmacy, Tirupati
At present very little is known about the role of Rho-kinase (ROCK) activity in the effects of temperature on vascular reactivity. To evaluate the role of ROCK activity in the cooling (28 ˚C)- and warming (41˚C)-induced effects on vascular reactivity, isolated calf cardiac vein rings were studied. Rings obtained from calf hearts were suspended in organ baths containing 25 ml of Krebs-Henseleit solution, maintained at 37 ˚C, continuously gassed with 95% O2-5% CO2. At the end of the resting period, the preparations were contracted with carbachol (10-6 M), serotonin (5-HT, 10-6 M), U46619 (10-7 M), PGF2α (10-6 M), or endothelin-1 (ET-1, 10-8 M) at 37˚C in different preparations. The same protocol was repeated at 28 ˚C and 41˚C after the preparations were allowed to equilibrate at this temperature for 60 min. In order to analyze the role of ROCK activity in the cooling- and warming-induced vascular response, each contractile agent was applied in the presence of fasudil (10-6 M) or Y-27632 (10-6 M). Carbachol, 5-HT, U46619, PGF2α and ET-1 produced reproducible contractions. Cooling decreased the contractions to carbachol, 5-HT, U46619, PGF2α and ET-1 and warming enhanced significantly. Treatment with fasudil and Y-27632 at both 28 and 41˚C decreased the responses to carbachol, 5-HT, U46619, PGF2α and ET-1. The results of this study suggests a role for ROCK signalling in the temperature-induced changes of calf cardiac vein.
6 , 2 , 2016
98 - 102