Abstract
Resistance of rabbits, long surviving double suprarenalectomy, to nicotine, histamine, ephedrine and typhoid vaccine (in 0.5 per cent carbolic acid saline solution) was compared with that of normal rabbits. Adult, male animals of about the same weight were experimented on; they were fed and treated otherwise in quite the same manner, and poisoning with one and the same dosage of a chemical was run simultaneously on both kinds of rabbits, normal and decapsulated. Nicotine, histamine and ephedrine were dissolved in physiological saline solution of a certain quantity for each, regardless of amount of the chemical, and introduced into the ear vein always with exactly the same velocity. Typhoid vaccine was intraperitoneally injected; the toxicity of this matter is really largely due to the vehicle.
The poisoning symptoms elicited by application of various dosages were closely observed, and the maximum non-lethal dose, that is the greatest dose which is poisonous to animals but does not kill them, and the minimum lethal dose were determined. The results are again summarized in Table XIII, together with the data on acetonitril.1)
Resistance to such chemicals was indefinitely smaller in doubly suprarenoprived rabbits than in the normal controls, but the difference was never large in those rabbits long surviving double decapsulation, and the magnitude of diminution in resistance apparently depends at least largely upon the length of time allowed to elapse from the first and the second decapsulation till the injection, and the chemicals, under discussion, themselves have no significant bearing upon them, as far as our experiments are concerned. The present experiments were mainly undertaken about two months after the last decapsulation. We are fully aware that we could get more definite views in respect to this question provided the first and second decapsulation and injection were carried out invariably with definite spells between them. In fact the periods between were taken at random.
That the regaining of resistance to toxines of the animals deprived of both suprarenals with lapse of time after decapsulation has some defmite relationship to the hypertrophy of the accessory cortical tissues has been properly alluded to by several experimentalists. In this respect it is worth while to review a work of Kojima23) on the compensatory hypertrophy of the fellow gland after a single decapsulation and of the accessories after double capsulation with the present data; some quantitative data are given there.
There are some substances which are alleged to act incomparably excessively toxic to animals deprived of the suprarenals, as acetonitril (100 times) by Crivellari, 4) in contrast to nicotine, histamine, ete., typhoid vaccine (100 times) by Shiozawa, 20) who failed to adhere to Lewis24) in finding a considerably greater increase of susceptibility of rats to morphine through double decapsulation (400-500 times). It is a further question whether or not one can find various degrees of diminution in resistance of rabbits by applying various chemicals if they are administered only a few days after loss of both suprarenals.
Finally the present data may be briefly recapitulated for the sake of convenience by saying that the sensitiveness of rabbits to nicotine, histamine, ephedrine, and typhoid vaccine (in 0.5 per cent carbolic acid saline solution) was not wholly identical but only a little inferior to that of normal, when tested about two, three months or somewhat later after double suprarenalectomy.
