Supranodose vagotomy eliminates anandamide-evoked cardiorespiratory depression in anaesthetized rats

The contribution of VR1 and CB1 receptors and the role of the afferent vagal pathway in modelling of cardio-respiratory effects of anandamide in rats

“…The dose of intravenous anandamide (1 mg kg − 1 ) evoked apnoea and the decrease of V T during renewed post-apnoeic breathing in intact rats in accordance to the previous study (Kopczyńska and Szereda-Przestaszewska, 2006).…”

“…The differences between these results and those of and Lin and Lee (2002) have been explained partly in the previous paper (Kopczyńska and Szereda-Przestaszewska, 2006). In Lin and Lee's experiments there was no apnoea after the perineural pretreatment of the vagus by capsaicin.…”

“…Prior to the use, dilutions were made with saline in order to minimize the effect of the solvent and to obtain the final 9.6% concentration of ethanol, containing the proper dose of the drug. The doseresponse curve of the respiratory variables to intravenously injected anandamide was determined with three different doses of anandamide (0.3, 0.6 and 1 mg kg − 1 ) in intact rats in preliminary experiments in the previous work (Kopczyńska and Szereda-Przestaszewska, 2006).…”

“…The reflex responses to anandamide challenge into the right atrium are nearly abolished by perineural pretreatment of both cervical vagi (Lin and Lee, 2002). Post-anandamide effects are eliminated by supranodose vagotomy, but they are not eliminated by midcervical vagotomy while the drug is injected into the femoral vein (Kopczyńska and Szereda-Przestaszewska, 2006) or intra-arterially (Smith et al, 2001).…”

“…Basing on the fact that 1) the post-anandamide effects were not abolished by midcervical vagotomy (Kopczyńska and Przestaszewska, 2006) which suggests that this drug would preferentially stimulate extrapulmonary, presumably laryngeal afferents and 2) respiratory effects of anandamide may be mediated by VR1 or/and by CB1 receptors, the present experiments have been designed to explain 1) the afferent laryngeal and cervical vagal pathway of the cardio-respiratory effects induced by anandamide administration into the femoral vein and 2) the contribution of VR1 and CB1 receptors in the post-anandamide cardio-respiratory response.…”