Objective: To explore the effects and mechanisms of Dendrobium nobile Lindl.
alkaloids (DNLA) on myocardial lipid metabolism during
ischemia-reperfusion in dogs undergoing
cardiopulmonary bypass (CPB). Methods: Twenty-four healthy hybrid dogs, half male and half female, were randomly divided into
sham group, model group,
solvent control group and treatment group (DNLA, 6 mg/kg) (n=6), all of which were established with CPB. Except for the
sham group, the aorta of the other groups was occluded for 60 min and then reopened. The uptake rate of
free fatty acids, the concentration of long-chain
acyl coenzyme A (LCACoA),
mRNA and
protein expression of
fatty acid translocase
enzyme/CD36 (FAT/CD36) in myocardial tissue and the cardiac function indexes were measured at 4 time points: before
cardiopulmonary bypass (T1), 15 min (T2), 60 min (T3), and 90 min (T4) after reperfusion in each group. Results: Before CPB, there were no statistically significant differences in the uptake rate of
free fatty acids, the concentration of LCACoA and
mRNA expression of FAT/CD36 in myocardial tissue in each group (P>0.05). After the opening of the aorta, the above indexes in model group [(35.8±4.7)%, (8.55±1.51) nmol/g, 3.23±0.68] and treatment group [(27.4±2.7)%, (6.10±1.38) nmol/g, 2.20±0.56] were higher than those in
sham group [(19.6±3.9)%, (4.16±0.81)nmol/g, 1.19±0.52], which were the highest at T2, and then gradually decreased (all P<0.05). Compared with the model group, the increase of above indicators in the treatment group was significantly lower at T2 (all P<0.05). Before CPB, there was no statistically significant differences in cardiac function indexes [left ventricular systolic pressure (LVSP), left ventricular end-diastolic pressure (LVEDP) and±dp/dtmax] among the groups (P>0.05). After the aorta was opened, the above indexes in model group [(76.5±9.1) mmHg, (31.1±2.9) mmHg, (1.2±0.4) mmHg/ms, (-0.9±0.1) mmHg/ms] and treatment group [(92.9±8.7) mmHg, (25.3±3.6) mmHg, (1.8±0.4) mmHg/ms, (-1.3±0.1) mmHg/ms] were lower than those in
sham group [(165.5±12.9) mmHg, (6.5±0.5) mmHg, (3.3±0.6) mmHg/ms, (-2.9±0.3) mmHg/ms] (all P<0.05), but the impairment degree of cardiac function indicators in treatment group was significantly lower than that those in model group (all P<0.05). Conclusion: During CPB in dogs, DNLA can inhibit the abnormal expression of FAT/CD36, decrease the uptake of
free fatty acids, and reduce the abnormal accumulation of LCACoA in myocardium,thereby alleviating the myocardial injury after
ischemia-reperfusion.