The results detailed in this thesis suggest that the more or less transient hypertension of acute renal damage can be prevented or terminated by renal denervation. These results appear to be at variance with those of Page and Collins, but there is a hypothesis that admits of both sets of observations. Certain personal clinical investigations that are still in the initial stave have led one to realise more fully that arteriolar tonus is maintained by two factors, - (a) the autonomic constrictor impulses, and (b) the intrinsic tonus of the plain muscle of the arteriolar wall. Of these two factors the latter is far the most important, and it may well be that when the kidney is damaged and when there arises the necessity to raise the arterial blood pressure by a generalised arteriolar hypertonicity the first mechanism that operates is a rapid phasic nervous vasoconstriction, the operation of which can be prevented by renal denervation. Such a possibility is also indicated by Pickering's (1936 b) observations in acute nephritics. On the other hand if the renal damage is progressive and becomes chronic then a more sustained hypertension is mediated by an increase of the intrinsic tonus of the plain muscle of the arteriolar wall. Such is independent of nervous influence and hence is not susceptible to renal denervation (Page and Collins).
The results, therefore, described in this thesis are applicable only to the initial compara- :tively transient hypertension of acute renal damage damage. It is hoped in time to test the validity of this hypothesis by producing experimentally a chronic renal hypertension by means of a severe advanced glomerulo-nerhritis, and by observing the effects of renal denervation in such a hypertension. Dogs are probably more suitable for the production of such a chronic hypertension, and at present goats are being subjected to a series of injections of dog kidney emulsion in order to obtain a serum which will produce the necessary glomerulo-nephritis.
The research described is to be regarded merely as the first stare in the investigation of renal hypertension. Given continued opportunity it is confidently anticipated that in the course of a few years additional light will be shed on the problem of renal hypertension.