Effects of Bretylium, Reserpine, Guanethidine and Sympathetic Denervation on the Noradrenaline Content of the Rat Submaxillary Gland

After sympathetic denervation the noradrenaline content of the rat submaxillary gland decreased slowly during the first 8 hours and disappeared completely in 24 hours. Reserpine and guanethidine caused depletion of noradrenaline from denervated as well as innervated glands. In the case of reserpine the denervated gland was slightly less depleted (p < 0.05). The noradrenaline depletion produced by treatment with these two drugs and by sympathetic denervation was significantly reduced by simultaneous injection of bretylium. In addition bretylium had a releasing effect, not as striking as that of rescrpine and guanethidine, but highly significant. The implications of these results are discussed.