To compare the cardiotoxicity induced by ropivacaine and bupivacaine and to investigate the mechanism of cardiotoxicity, 24 mature New Zealand rabbits were divided randomly into control group (group C), ropivacaine group (group R) and bupivacaine group (group B). Hearts were drawn out rapidly from the anesthetized animals and cardiac perfusion was performed immediately. Ropivacaine 500 ng/ml (group R) or bupivacaine 500 ng/ml (group B) was added to the perfusion solution. Ventricular myocardial ATP, ADP and AMP were measured with high performance liquid chromatogram. The ability of myocardial mitochondria oxidation to pyruvate or palmitoylcarnitine was detected with Clark electrode. Our results showed that myocardial ATP and ADP decreased significantly (P<0.05) in group R and most significantly (P<0.01) in group B as compared with group C. Myocardial ATP and ADP decreased most significantly (P<0.01) in group B as compared with group R. The changes of myocardial AMP revealed significant difference among three groups. The changes of pyruvate oxidation exibited no significant difference among the three groups. Palmitoylcarnitine oxidation decreased markedly (P<0.05) in group R and most significantly (P<0.01) in group B as compared with group C. The present study indicated that the inhibition of lipid substrate oxidation may be responsible for the cardiotoxicity induced by bupivacaine and ropivacaine. The cardiotoxicity induced by ropivacaine is far more less than bupivacaine.

To study the expression of beta-human chorionic gonadotropin (βhCG) genes in renal cell carcinomas (RCC) and benign renal disease tissues, nested reverse transcription-polymerase chain reaction (RT-PCR) and restriction endonuclease analysis were employed to detect the expression of βhCG genes in 44 cases of RCC tissues and 24 cases of benign renal disease tissues. It was found that 52% RCC samples revealed positive for βhCG mRNA expression. Positive rate in advanced stage and poorly differentiated RCC was higher, but there was no significant difference. The positive rate of βhCG mRNA expression was 54% in 24 cases of benign renal tissues, including 3 cases out of 6 polycystic kidneys, 7 cases out of 13 renal atrophies, 2 cases out of 2 oncocytomas and 1 case out of 2 pyonephrotic kidneys. β7 was most frequently transcribed subtype gene independent on the histology. These findings suggested βhCG gene transcription is not only involved in RCC but also in benign renal diseases.