KIDNEY-EXPLANTATION EXPERIMENTS 



IN RELATION TO ARTERIAL 



HYPERTENSION 



AFTER various experiences -with Minkowski's method of explanting the un- 

 /l. cinate process of the pancreas under the skin,'- this method was first ex- 

 tended to the spleen about 1916. The purpose then was to provide a simple 

 means, without laparotomy, of injecting various substances, particvdarly sugar, 

 into the portal circulation. This could be accomplished by injecting into the 

 splenic parenchyma by needle puncture; or by a small skin incision the injec- 

 tion could be made into a branch of the splenic vein. This method was dis- 

 cussed at the time with Dr. H. M. Evans, and though the experiments were 

 broken off because of adverse conditions it seems possible that the method mav 

 still be found useful for some purposes. 



Explantations of the spleen and kidney were used for otlier purposes in 

 Morristown from 1922 onward. Loesch, Witts and Zimmermann^'^ in their 

 studies of splenic physiology found that the normal volume changes of the 

 organ were hindered by adhesions to the subcutaneous tissue, and, after the 

 return of Dr. Witts to England, Barcroft and Stephens'^ overcame this difficulty 

 by the remarkable device of placing the naked spleen outside the skin and 

 demonstrating that it can survive and function thus indefinitely. Explantations 

 of the kidney were mentioned in several publications" "'^ and also in unpub- 

 lished statements at medical meetings, particularly at the congress on kidney 

 diseases in Minneapolis in 1930. According to the papers published bv Rhoads, 

 Van Slykc, and other writers," '"" they apparently derived suggestions only 

 from the Barcroft and Stephens work," which was by an altogether different 

 method, and knew nothing of the above-mentioned explantations at Morris- 

 town and at the Rockefeller Institute Hospital, of which the "Rhoads method" 

 was a precise copy. Previous reminders'" " of these facts have passed unnoticed. 



In this renal-vascular research, now resumed after long suppression, kidney 

 explantation is being employed for some of the purposes for which it was 

 originally devised. The present paper will correlate the former work with that 

 now in progress, by giving a synopsis, in the nature of a preliminary communi- 

 cation, of results to be described in a series of forthcoming papers. The topic 

 may be divided into: (1) diet in relation to blood pressure and kidney size; (2) 

 production of acute and chronic hypertension; (3) pathology of the kidneys. 



1. Diet in Relation to Blood Pressure and Kidney Size 



Both femoral and brachial blood pressures are determined by a newly reported 

 auscultatory method" suitable for frequent readings without disturbance. The 

 three dimensions of explanted kidneys can be measured with calipers ^vithin 

 limits of error which are appreciable but still not sufficient to confuse the 



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