Warming and response to contractile agents in calf cardiac vein: role of the nitric oxide

Abstract

The effects of warming on the response to various contractile agents of calf cardiac vein were studied using 2.5-mm long cylindrical segments. Concentration-response curves for carbachol (10(-9)-3 x 10(-4) m), 5-hydroxytryptamine (5-HT; 10(-8)-3 x 10(-3)), potassium chloride (KCl; 10(-4)-5 x 10(-2) m) and calcium chloride (CaCl2; 10(-4)-10(-2)) were isometrically recorded at 37 and 41 degrees C (warming). During warming the sensitivity, but not the maximal response, of carbachol 5-HT, KCl, and CaCl2 was significantly higher than at 37 degrees C. Warming to 41 degrees C after treatment with NG-nitro-L arginine methyl esther (10(-5) m) did not modify the effect of warming. These results suggest that nitric oxide seems to have no role in the warming-induced responses in calf cardiac vein.

Effects of cooling and warming on 5‐hydroxytryptamine‐ and acetylcholine‐induced contractions of human umbilical vessels: role of nitric oxide

“…In the present study, we also investigated the role of nitric oxide in cooling-and warming-induced responses. In previous studies, we observed similar findings in different tissues such as rabbit aorta [14], calf coronary artery and cardiac vein [15,16]. This suggested that during cooling or warming the response to the vasoconstrictors is not modulated by nitric oxide.…”

“…In addition to agonist-mediated constriction, limited evidence suggests that vascular smooth muscle responsiveness to nitric oxide and related factors can be influenced by temperature [11][12][13]. Recently, we studied the effects of temperature on the contractile response of smooth muscle in various species and vessels, and observed that the contractile responses were temperature-dependent but endothelium seems to have no role in the temperature-induced responses [14][15][16].Thus, despite current research to determine the effects of temperature on vascular reactivity of different animals species, studies with human tissues remain incompleteThe effects of cooling (to 28°C) and warming (to 41°C) on the vasoconstrictions induced by 5-hydroxytryptamine (5-HT) and acetylcholine (ACh) and the role of nitric oxide in these effects were analyzed in human umbilical artery and vein. 5-HT (10 )9 -10 )4 M) and ACh (10 )9 -10 )4 M) induced concentration-dependent contractions at 37, 28 and 41°C.…”

“…In addition to agonist-mediated constriction, limited evidence suggests that vascular smooth muscle responsiveness to nitric oxide and related factors can be influenced by temperature [11][12][13]. Recently, we studied the effects of temperature on the contractile response of smooth muscle in various species and vessels, and observed that the contractile responses were temperature-dependent but endothelium seems to have no role in the temperature-induced responses [14][15][16].…”

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

“…To my knowledge, this is the fi rst study to show the effects of PDE inhibition of calf cardiac vein contracted with carbachol. In different studies it is reported that cooling (to 28 °C) induced subsensitivity (21) and warming (to 41 °C) induced supersensitivity (22,23) to carbachol in calf cardiac vein. In these studies, it has also been observed that endothelial nitric oxide does not play a role in the decreased sensitivity of noncutaneous vessels to contractile agents during cooling.…”

“…Coronary venous system (cardiac veins) collects one-third blood of the coronary circulation and is considered to be an important site for the blood-tissue exchange of water and nutrients, as well as a possible determinant of ventricular distensibility. The temperature utilized in this study; 28 °C, for cooling was considered to be "moderate cooling" and 41 °C, "moderate warming" temperature accordingly to previous studies (21)(22)(23)(24).…”