THE HUMAN PITUITARY BODY

1. The human pituitary body weighs about half a gramme, and on the average is somewhat larger in females than in males. It contains in the mean 76·6 per cent. of water. 2. In the cases of nervous disease (asylum cases) from which our material was obtained, there is in the pituitary body, as a rule, no noteworthy departure from the normal condition. 3. The anatomical description of the mammalian pituitary body, as given by Herring, applies equally well to that of the human subject. The invasion of the posterior lobe by the cells of the pars intermedia is a marked feature. The number and size of the cysts which contain a colloid material is variable; as a rule, these are most numerous in the pars intermedia. 4. Sufficient material is available in a single human pituitary body for the examination of the physiological action of extracts. If one pituitary is ground up and boiled with 10–12 c.c. of Ringer's solution, and filtered, sufficient is obtained for injecting two quantities of about 5 c.c. each. The strength of such solutions is about one‐quarter of that employed by Schäafer and Herring, who mainly used what they term a 1 per cent. solution, i.e., 1 gramme of the dried posterior lobe, to 100 c.c. of Ringer's solution. 5. The dried glands maintain their physiological activity for many months. 6. Extracts of the posterior lobe produce the same effects as those described by Schäfer and Herring for that of other mammals. In anaesthetised cats these effects are:— i. Rise of arterial blood‐pressure; this occurs only on the first injection. ii. A prolonged expansion of the blood‐vessels of the kidney, though arterial constriction is produced in other parts. iii. Diuresis. 7. Extracts of the anterior lobe are wholly inactive in all these directions; occasionally a slight fall of pressure (the usual effect of most tissue extracts) is obtained. 8. In the cases examined, no relationship was found to exist between the condition and activity of the pituitary body on the one hand, and the nervous disease from which the patient suffered on the other. There was a similar absence of discoverable relationship between the pituitary and the disease from which the patients ultimately died, and the condition of their kidneys. 9. The pituitary bodies examined presented no noteworthy departure from the normal, except in two cases; in one of these (Case 18) the cysts were visible to the naked eye, and the pituitary was markedly calcareous; yet extracts of it produced the usual effects. In the other case, the anterior lobe of which presented a necrotic appearance (Case 19), the extract was inactive. 10. In five other cases negative or slight effects were also obtained as the result of the injection of the extracts. In Cases 3, 13, 20, and 21 this may possibly be explained by the length of the interval between the autopsy and the death of the patient; although in other cases, where the interval was as long, no deterioration due to post‐mortem changes was observable. In Case 17 the extract was inactive, although the interval between death and autopsy was only three hours, and the pituitary body was normal histologically. 11. The substances in the posterior lobe responsible for these actions appear to be two in number, one producing the rise in blood‐pressure, the other the effect in the kidney, since occasionally one or other action may be absent. 12. Although these substances are probably developed in connection with the activity of the cells of the pars intermedia, there is no available evidence for connecting either of them with the colloid material in the cysts. 13. In view of the suggested vicarious relationship between thyroid and pituitary, we have examined the latter organ for iodine both in man and ox, but with negative results.