Differential expression of HSP70 and ultrastructure of heart and liver tissues of rats treated with adriamycin: protective role of L-carnitine
Strauss, M.; Porras, N.
Investigacion Clinica 48(1): 33-43
2007
ISSN/ISBN: 0535-5133 PMID: 17432542 Document Number: 610973
The anticancer drug adriamycin has been associated with tissue oxidative stress. In this regard, the promotion of anti-stress protein synthesis by L-carnitine has been suggested in chronic adriamycin-induced cardiomyopathy in rats. However, the protective role of L-carnitine in cardiac and hepatic tissues after short-term adriamycin treatment is unknown. HSP70 in the supernatant of homogenized cardiac and hepatic tissues after short-term adriamycin treatment was determined by Western blot analysis with and without L-carnitine protection and compared to the subcellular characteristics of both tissues by transmission electron microscopic analysis. Female Sprague-Dawley rats (n=6; body weight, 40-60 g) were randomized into four groups: control, adriamycin, L-carnitine and L-carnitine-adriamycin. Saline, adriamycin (15 mg/kg body weight) and L-carnitine (20 mg before adriamycin) were given intravenously (0.1 ml) to the corresponding mice groups. HSP70 accumulation in both cardiac and hepatic tissues was different between the control and the adriamycin group. HSP70 was higher in the liver than in the heart in both groups with and without L-carnitine protection. The nuclei of cardiac cells in the adriamycin group showed some alterations in form, including irregular perinuclear cysternae with invaginations of different sizes, which were not observed in the L-carnitine-adriamycin samples. Considering the differential expression of HSP70 between liver and heart, our results may be important for understanding the role of these proteins in the adriamycin-induced distinct levels of organ damage and dysfunction. We suggest that exogenous administration of L-carnitine may enhance the relationship between the cellular energy state and the activation of heat shock response by an unknown mechanism. L-carnitine may enhance HSP70 in a cellular-type manner.