The role of phosphodiesterase activity on the temperature-dependent responses of calf cardiac vein

Abstract

To evaluate the role of phosphodiesterase (PDE) activity in the cooling (to 28 °C) and warming (41 °C)-induced effects of carbachol on calf cardiac vein. 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 (10-9-3x10-4M), at 37 °C. 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 PDE activity in the cooling-and warming-induced vascular response, carbachol (10-9-3x10-4M) was applied in the presence of cilostazol (10-6 M), IBMX (10-6 M) and rolipram (10-6 M), respectively. The sensitivity of carbachol was significantly lower during cooling, and higher during warming. Cooling to 28 and warming to 41 °C, after treatment with IBMX, cilostazol or rolipram, significantly decreased the sensitivity to carbachol (p<0.05). The results of the present study suggest that PDE activity plays an essential role in cooling-and warming-induced changes of calf cardiac vein treated with carbachol (Tab. 1, Fig. 2, Ref. 34). Text in PDF www.elis.sk.