ACUTE EFFECTS OF GALLIUM CHLORIDE ON VENTRICULAR-FUNCTION AND METABOLISM OF THE LANGENDORFF PERFUSED RAT-HEART

The effects of two concentrations of GaCl3 (1.79 mu M and 7.17 mu M) w ere studied on isolated perfused paced rat hearts. All hearts were sub mitted to an equilibration period of 20 minutes under normal condition s of oxygenation (95% O-2, 5% CO2) and with 11 mM glucose in Krebs-Hen seleit buffer. At the end of the perfusion (80 min) tissue Ga contents were 98.0 +/- 13.8 and 200.2 +/- 28.5 nM/g of wet weight for the lowe r and the higher Ga concentrations respectively. Left ventricular deve loped pressure (LVdp) as well as +LVdp/dt and -LVdp/dt were similar in control and Ga-treated groups during the 60 minutes following the equ ilibration period. At the same time mean coronary flow and oxygen cons umption were lower (p < 0.05) in hearts perfused with 7.17 mu M Ga tha n in the control group. Lactate production did not differ in the contr ol and Ga-treated groups. Mean creatine kinase release was lower (p < 0.05) in the 7.17 mu M Ga-treated group than in the 1.79 mu M Ga-treat ed and control groups. Intratissular malondialdehyde as well as glycog en and ATP concentrations did not differ in all groups at the end of t he experiment. Gallium chloride partially prevented the unavoidable oe dema resulting from using saline Krebs-Henseleit solution. In conclusi on, acute GaCl3 administration improves the functionality of the Lange ndorff-heart model.