I.—PHYSIOLOGY 153 
regards these cells as the origin of the pressor principle, the excess pro- 
duction of which is primarily responsible for some of the phenomena 
accompanying the condition. Hofbauer in 1918 suggested that the 
toxeemias of pregnancy, and especially eclampsia, might be due to over- 
action of the posterior lobe of the pituitary body, and other observers have 
come to the same conclusion. Cushing is inclined to support this view. 
Numerous records of hypertension associated with basophil adenoma of 
the pituitary have been published by pathologists since their attention 
was drawn to it, though the exact mode of production of the secondary 
lesions is not yet understood. Kraus suggests that cholesteroleamia may 
be a factor. Ashoff believes that the deposition of cholesterol in the 
intima of the arteries is the starting point of atheroma, and that the 
deposition of calcium follows. Moehlig found that in rabbits, receiving 
a diet containing excess of fat, repeated injections of pituitrin produce 
atheroma and other evidences of arteriosclerosis. ‘The phenomena 
associated with Cushing’s syndrome, or pituitary basophilism, are ascribed 
by some to over action of the adrenal cortex, but evidence is accumulating 
in favour of their primary origin from the pituitary body. 
| Magnus and Schafer described a diuretic action of posterior lobe extract 
in 1906. In experimental animals the diuretic effect of an intravenous 
injection is often very pronounced, but it is only temporary, and is suc- 
ceeded by a cessation of urine secretion. Farini and Van der Velden, in 
1913, independently ascertained that extracts of the posterior lobe, injected 
hypodermically, act as antidiuretics, and can be used to control the polyuria 
of diabetes insipidus in man. The work of Starling and Verney upon the 
isolated kidney of the dog showed that pituitrin increases the percentage 
and amount of chlorides in the urine while decreasing the water eliminated. 
Starling and Verney concluded that the pituitary body provides a sub- 
stance which normally regulates the output of water and chlorides by the 
kidneys. Priestly showed that pituitrin inhibits for several hours in man 
the diuresis which normally follows the intake of large quantities of water, 
and this antidiuretic property is now well established. ‘The hormone, if 
it has a separate entity, is found in vasopressin and not in oxytocin. 
Maddock obtained persistent polyuria in dogs by the application of 
silver clips to the stalk of the pituitary, a result which Cushing believes to 
be due to a blockage of the secretion of the posterior lobe which is thereby 
prevented from passing into the blood vessels or directly into the cerebro- 
spinal fluid of the third ventricle. Camus and Roussy (1920), and Bailey 
and Bremer, showed that polyuria might be equally well provoked by 
injury of the tuber cinereum and other parts of the hypothalamus. 
Richter has also proved that polyuria and polydipsia may be induced in 
the rat by puncture of the floor of the third ventricle in situations which 
cause no direct injury to the pituitary body. Eaves and Croll find that in 
the human subject severe lesions of the hypothalamus do not give rise 
to diabetes insipidus, but that relatively mild lesions may do so. The 
injection of pituitrin has been employed successfully in the treatment of 
many cases of diabetes insipidus, but not in all. Lesions of the hypo- 
thalamus are liable to interfere with the normal outlet for the products of 
the lobe by damaging the venous portal system or destroying the nerve 
