Effect of dopamine on diuresis and its role in forming a renal CR
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Four female mongrel dogs were used. Three had both ureters transplanted to the surface of the abdomen and one had a unilateral nephrectomy on the left and the right ureter transplanted to the abdomen. In dogs with externalized ureters our results with dopamine show changes in cardiac rate and renal secretion. The method used was 1) injection of dopamine, 2) measurement of subsequent changes in renal secretions (unconditional reflex), 3) and heart rate (HR). After 40 daily injections im of 2.5 mg/kg in normal saline the possible production of a diuretic CR was tested by injecting normal saline im and a tone was used as a signal. The control for normal saline showed no change in HR nor any of the constituents measured. The dopamine injection resulted in an increase of epinephrine in the urine of 300–600 per cent for 45 minutes; of norepinephrine of 200–500 per cent for 45 minutes; of an increase of 50 per cent in urine volume for 45 or more minutes; of absolute Na secretion of 49 per cent, of K, 20 per cent; of creatinine, 39 per cent (average in 3 dogs for 45 minutes diuresis). When the conditional stimulus (normal saline and tone) was given after several months training with the conditional signal and the injection of dopamine, there was no significant CR change to the HR nor any of the above components of urine. The conclusion is that in spite of the great increase of urine volume and composition of above substances there was no significant increase to the signals for the im injection of dopamine,i.e., no conditioning to dopamine.
KeywordsDopamine Normal Saline Conditional Stimulus Urine Volume Sodium Excretion
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- Bliss, E. L.: Metabolism of norepinephrine, serotonin and dopamine in rat brain with stress.J. Pharmacol. Exp. Ther.,164:1, 122, 1968.Google Scholar
- Goldstein, A., Aronor, L., and Kaiman, S.: Principles of Drug Action: The Basis of Pharmacology. New York, Hoeber, 1968.Google Scholar
- Hawk, P. B., Oser, B. L., and Summerson, W. H.: Practical Physiological Chemistry. Philadelphia, The Blakiston Co., 1947; pp. 839–842.Google Scholar
- Livingston, A.: Inability to condition a peripheral activating drug.Pav. J. Biol. Sci.,9:35–45, 1974.Google Scholar
- McNay, J. L., McDonald, R. H., and Goldberg, L. L: Direct renal vasodilatation produced by dopamine in the dog.Circ. Res., XVI, 1965.Google Scholar