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

Abstract

Abstract:Objective: 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. Material and methods: 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%O 2 -5%CO 2 . At the end of the resting period the preparations were contracted with carbachol (10 -9 -3x10 -4 M), 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 (10M) was applied in the presence of cilostazol (10 -6 M), IBMX (10 -6 M) and rolipram (10 -6 M), respectively. Results: The sensitivity of carbachol was signifi cantly lower during cooling, and higher during warming. Cooling to 28 and warming to 41 °C, after treatment with IBMX, cilostazol or rolipram, signifi cantly decreased the sensitivity to carbachol (p<0.05). Conclusion: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

Moderate hypothermia and responses to calcium channel blockers – Role of the nitric oxide

“…In this work, we studied the effects of moderate hypothermia on calcium channel blockersinduced vasodilatation of calf cardiac vein, paying special attention to the role of nitric oxide in these responses. The calf cardiac vein is an easily accessible smooth muscle preparation and there is limited information (12,19,20) about the effects of temperature in non-cutaneous vessels. Moreover, the effects of hypothermia were generally studied with contractile agents.…”