{'fraction_non_alphanumeric': 0.0472193074501574, 'fraction_numerical': 0.023084994753410283, 'mean_word_length': 4.6117647058823525, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Induction by verapamil of a rapid increase in ATP consumption in multidrug‐resistant tumor cells

A marked increase in cellular ATP consumption was induced by verapamil in the multidrug‐resistant (MDR) cell line 2780ad, but not in the drug‐sensitive parental cell line A2780. A group of structurally unrelated drugs in concentrations known to reverse MDR, but not the verapamil analog tiapamil, a weak modulator of MDR, had similar effects. This effect was saturated at verapamil concentrations of about 1 μM.These data demonstrate that verapamil concentrations in MDR cells are maintained at a low level at the expense of ATP hydrolysis, and provide a first indication of the amount of metabolic energy used in this process.— Broxterman, H. J.; Pinedo, H. M.; Kuiper, C. M.; Kaptein, L. C. M.; Schuurhuis, G. J.; Lankelma, j. Induction by verapamil of a rapid increase in ATP consumption in multidrug‐resistant tumor cells. FASEB J. 2: 2278‐2282; 1988.