A Note on the Hyperpnoic Action of Ammonium Chloride in Cats

Abstract

As is readily seen by examining the above small table, the results with the intact cats and the bilaterally splanchnicotomized fell into the same line with those of Morita; that is, the normal cats respond against the subcutaneous injection of ammonium chloride with an increase in the rate of breathing, remarkable or moderate; a definite acceleration was unperceived in a few individuals only. On the other hand, the double splanchnicotomy was capable of abolishing this reaction to a great extent, namely in over half of the cases an unmistakable increase in the respiration rhythm failed to occur. The events caused by the salt in the cats, whose suprarenal body on one side was removed and the splanchnic nerves on the other divided, did not differ very materially from those with the bilaterally splanchnicotomized, but plainly differed from those with the unilaterally splanchnicotomized but not suprarenalectomized ones. In relation to the hyperpnoic action of ammonium chloride the suprarenalectomy appears, thus, to have a similar bearing as to the splanchnicotomy, though it may be somewhat inferior. I practised great care not to interfere with the splanchnic fibres which do not destinate in the suprarenal gland, but it is a matter of great difficulty to speak with confidence of the integrity of all or nearly all of such fibres. We are acquainted with the facts, which indicate that the removal of the suprarenal gland may run a risk of damaging the splanchnic nerves in an unexpected manner. The reports, for example, that the change in the blood pressure curve caused by sensory stimulation or stimulation of the peripheral end of the splanchnic nerve disappears after the extirpation of both the suprarenal glands, were annihilated by subsequent researches. The failure of the change was really caused by injury of the splanchnic nerves and not by the removal of the glands themselves. On perusal of the literature it may be justifiable to assume that the rôle of the suprarenal gland in the hyperpnoic action of ammonium chloride cannot be explained by the oversecretion of epinephrine. It is open to further investigation.