The mechanism of the depressor action of dog's urine with some observations on the antagonistic action of adrenalin

Summary

The intravenous injections of dog's urine into the dog causes an abrupt but transient lowering of blood pressure, varying from 20 to 90 mm. Hg (usually 40 to 70), not accompanied by disturbance of heart action and with little respiratory disturbance. Section of the spinal cord, vagi, cervical sympathetic and splanchnic nerves and destruction of cœliac ganglia and solar plexus individually or collectively does not abolish the depressor action. Physiological and pharmacological experiments based on Dixon's studies of the action of apocodeine show that when the nerve endings are so paralyzed by apocodeine that adrenalin causes little or no reaction, the urine also has no effect. Likewise, in normal animals, and in those with central vaso-motor influence eliminated, the action of urine is antagonistic to that of adrenalin and barium and during the increased pressure due to electrical stimulation of the nerves of the splanchnic area, the urine causes a fall in pressure.