THE UPTAKE OF noradrenALINE BY THE ISOLATED RABBIT'S ATRIUM TREATED WITH RESERPINE

Abstract

After the transmembrane potential and spontaneous contraction of the isolated atrium of rabbit had been abolished by the addition of 10^-5 g/ml of reserpine, the addition of adrenaline or noradrenaline restarted the contraction but only washing of the preparation did not so (1, 2). In contrast to the depletion over ninety per cent of the extractable noradrenaline in the atrium from rabbit which had received 1.0 to 5.0 mg/kg of reserpine 10 to 16 hours before the isolation, the isolated atrium of the intact rabbit which ceased to beat as mentioned above was depleted only about 20 to 30 per cent of the normal content of n9radrenaline (3-5). It has been shown that the circulating noradrenaline is taken up, bound and retained at or near the sympathetic nerve endings of various tissues including the heart (6-8).
In this report, the effect of reserpine on the uptake of noradrenaline by the isolated atrium of rabbit was studied. The uptake of noradrenaline-¹⁴C by the isolated atrium of rabbit from the bath fluid when this substance was added into the bath fluid has been shown by Burn and Burn (9).