Cardiac function and responsiveness to beta-adrenoceptor agonists in rats with obstructive jaundice

Abstract

The function and role of the heart and the contribution of cardiac beta-adrenoceptors in the pathogenesis of circulatory failure in obstructive jaundice were studied in the 3-day bile duct-ligated (BDL) rat using three different techniques to measure cardiac function and beta-adrenoceptor activity, number, and affinity. The techniques were the pithed rat preparation, the isolated working heart preparation, and a competitive radioligand binding assay for beta-adrenoceptors. The results of these experiments were compared with those obtained in 3-day bile duct-manipulated (sham operated; SO) rats. Impaired indexes of basal cardiac contractility were observed in the BDL pithed rats and isolated working hearts. In these two preparations, responsiveness to norepinephrine and the beta-adrenoceptor agonists, isoproterenol and dobutamine, was unaffected by bile duct ligation. The affinity and number of cardiac beta-adrenoceptors in membranes from the hearts of SO and BDL rats were not significantly different from each other. These experiments have established for the first time that the 3-day BDL rat has a cardiac myopathy associated with intact responsiveness to beta-adrenoceptor agonists, a normal unchanged affinity and number of cardiac beta-adrenoceptors.

Down‐regulation of vascular α1‐adrenoceptors does not account for the loss of vascular responsiveness to catecholamines in experimental cholestasis

“…This is the first report of unchanged vascular al-adrenoceptors affinity and number in a rat model of experimental cholestasis. We have previously reported that BDL of 3 days standing does not cause down-regulation of cardiac P-adrenoceptors (6). Hence, the absence of change in either affinity or number of vascular al-adrenoceptors is consistent with our earlier observations on another adrenoceptor system in other tissues in the 3-day BDL rat.…”

In vivo and ex vivo effects of propofol on myocardial performance in rats with obstructive jaundice

“…Recorded parameters included HR, LVESP, LVEDP, (and ± dP/dt max ). Effects of propofol (12.5, 25, and 50 μmol/L) were tested using a method described by Jacob et al [18]. In rats that underwent 3-day BDL, Jacob [18] showed impaired basal cardiac contractility and reduced left intraventricular pressure using two preparations of pithed rats and isolated functioning hearts.…”

“…Effects of propofol (12.5, 25, and 50 μmol/L) were tested using a method described by Jacob et al [18]. In rats that underwent 3-day BDL, Jacob [18] showed impaired basal cardiac contractility and reduced left intraventricular pressure using two preparations of pithed rats and isolated functioning hearts. When the aortic flow and left ventricular pressure were stabilized, data were acquired for 30 consecutive seconds prior to drug testing.…”

Plasma BNP level combined with surgical Apgar score to predict operative major cardiac adverse events in malignant obstructive jaundice patients

“…Since Green et al described the cardiac injury of OJ firstly in 1986,23 studies afterwards have continuously confirmed that cardiac disfunction is one of the common complications in patients with OJ 24. Experimental studies indicated that effects of bile duct ligation on myocytes including decrease of contraction rates and amplitude leads to cardiac disfunction potentially 25. It is quite necessary to predict and intervene of MACE in the early stage of OJ operations.…”