Deneysel Septik Şok Modelinde Endotelin ve Nitrik Oksit’in Kalp Kasi Fonksiyonlarına Etkisi

Abstract

In this study, we investigated changes of cardiac muscle functions in both hyperdynamic and hypodynamic septic shock periods and possible roles of NO and endothelin. Atrium beat rate did not change in hyperdynamic period and increased in hypodynamic period (p<0,001). While atrium beat rate is expected to increase in hypodynamic period; bosentan and L-NAME decreased it (p<0,001, p<0,05 respectively). Bosentan and L-NAME shifted response of atrium beat rate to isoproterenol to the left and potency of isoproterenol increased in both periods, and shifted response of atrium beat rate to carbachol to the left in only hypodynamic period and increased the potency of carbachol. Atrium contraction significantly decreased in both periods (p<0,001). While bosentan partially restored atrium contraction in both hyperdynamic (p<0,01) and hypodynamic period (p<0,001), L-NAME partially restored atrium contraction in only hypodynamic period (p<0,001). Bosentan increased response of atrium contraction to isoproterenol in hypodynamic period (p<0,05). Bosentan and L-NAME shifted response of atrium contraction to carbachol to the left in hypodynamic period so increased potency of carbachol. Papillary muscle contraction did not change in both periods. Bosentan and L-NAME increased papillary muscle contraction in hyperdynamic period (p<0,01, p<0,001 respectively), insomuch that the value obtained from the increase of L-NAME’s effect was greater than the control group (p<0,05). In addition L-NAME increased papillary muscle contraction in hypodynamic period (p<0,01). The response of papillary muscle contraction to isoproterenol in hypodynamic period was increased (p<0,05) and when these dose-response curves are considered as a whole, bosentan increased isoproterenol response. L-NAME increased response of papillary muscle contraction to carbachol in both periods (p<0,05). These results show that NO and endothelin might play a role in positive inotropic and negative chronotropic effects for atrium in septic shock. Bosentan and L-NAME might increase potency of isoproterenol and carbachol for atrium beat rate and atrium contraction and only L-NAME might increase potency of carbachol for papillary muscle contraction in both periods via upregulation of adrenergic and cholinergic receptors and/or through post receptor factors.