The acquisition of resistance to anticancer agents used in chemotherapy is the main cause of treatment failure in malignant disorders, provoking tumours to become resistant during treatment, although they initially respond to it. The main multidrug resistance (MDR) mechanism in tumour cells is the expression of P-gly-coprotein (P-gly), that acts as an ATP-dependent active efflux pump of chemotherapeutic agents. Furthermore, an increased detoxification of compounds mediated by high levels of glutathione (GSH) and glutathione S-transferase (GST), has been found in resistant cells.
View Article and Find Full Text PDFThe most important mechanism in drug resistance is the multidrug resistance (MDR) phenomenon. It is possible to select MDR cells by in vitro exposure to cytotoxic agents. The resistance is due to the hyperexpression of the P-glycoprotein (P-Gp) that take drugs out from the cells.
View Article and Find Full Text PDFThe aim of this study is to investigate the effect of He-Ne continuous laser (12.6 mW, 632.8 nm), at low energy densities, on cell cycle synchronization of monolayer growing human colon adenocarcinoma cell line.
View Article and Find Full Text PDFRev Esp Cardiol
March 1989
210 patients with mild-moderate high blood pressure have been studied. These patients were followed up for 4-6 weeks. Fifty patients were treated with 50 mg hydrochlorothiazide + 5 mg amiloride daily; 40 with 160 mg oxprenolol daily; 22 with 30-40 mg nifedipine daily; 38 with 240 mg verapamil daily and 60 with 50-100 mg captopril daily.
View Article and Find Full Text PDFIn isolated segments of ileum excised from bilaterally adrenalectomized and nephrectomized rats, 10(-12) M angiotensin or 10(-3) M noradrenaline added to serosal medium stimulated both fluid transfer and NaCl transport. The alpha adrenergic antagonist phentolamine blocked the stimulation of fluid transfer induced by angiotensin. These results are consistent with the hypothesis that noradrenaline may mediate the increase of intestinal fluid absorption induced by angiotensin in the rat.
View Article and Find Full Text PDFIn segments of isolated proximal colon from bilaterally adrenalectomized and nephrectomized rats 10(-12) g angiotensin/ml added to the serosal medium stimulated fluid transfer and sodium transport whose increase was accompanied by a decrease in transepithelial potential difference and short circuit current. Transepithelial electrical resistance remained unchanged. Replacement of chloride by sulphate in the bathing medium blocked the response to angiotensin.
View Article and Find Full Text PDF