Cardiotoxicity of anticancer drugs with special reference to lipid peroxidation

65 CARDIOTOXICITY OF ANTICANCER DRUGS WITH SPECIAL REFERENCE TO LIPID PEROXIDATION. M.Yasumi, H.Okamori, S.Yoneda, I.Kimura, M.Maeda, K.Nakamura, A.Kusaba, A.Kizu, and H.Ijichi. 2nd Dept. of Int. Med. Kyoto Pref. Univ. of Med., Kyoto, Japan Role of'lipid peroxidation in cellular damage has been gradually recognized. In this paper, cardiotoxicity of anticancer drugs was evaluated in aspects of lipid peroxidation, which was measured with TBA reactions using butanol-pyridine extraction. The results were as follows : 1) TBA values of rat myocardium were elevated in rat subjected to administration of anticancer drugs. ( adriamycin,aclacinomycinA, etc ) 2) These elevations were suppressed by prior administration of alphatocopherol. 3) While concentration of alpha-tocopherol employed was indifferent from viability of L1210 cells. it was suggested that these drugs From these results, may be important in view point of lipid peroxidation with reference to pathogenesis of cardiotoxicity induced by these drugs.

ESTIMATED AFFINITY OF THE CHRONOTROPIC BETA-ADRENERGIC RECEPTOR OF HUMAN HEART, WITH SPECIAL REFERENCE TO THE HYPERTHYROIDISM. S.Hirakawa, H.Ito, N.Tonai, K.Ksmubara, S.Minatoguchi, M.Osamura. 2nd Dept. of Med., Gifu Univ. School of Med., Gifu, Japan We have made a report at this cbngress(2nd Meeting) that the patients with neurocirculatory asthenia(NCA) responded to a slow intravenous injection of isoproterenol (ISO) with a marked increase in heart rate(HR). The dose of IS0 administered were;0.5,1,2 and 3ug over one minute. The relationship between the effect(AHR) and dose was determined. Plotting the inverse of response against the inverse of IS0 "concentration", Lineweaver-Burk's plot was obtained. From this, the dissociation constant for drugreceptor complex(K) was calculated. l/K is affinity. In NCA the affinity was 0.397+0.023xI04ml/ug, i.e., about 3 times as large as the affinity in Vnormay' subjects (0.19 9+0.03xI04ml/ug). This study was recently extended to examine the patients with hyperthyroidism. The value of affinity did not differ between hyperthyroid patients and "normal" subjects. This result is in good agreement with a report on experimental hyperthyroid animals.