ROLE OF THE ADRENAL CORTEX REGENERATED AFTER ENUCLEATION IN THE RESISTANCE AGAINST HISTAMINE SHOCK

Abstract

SUMMARY 1. The resistance of rats to the injection of histamine has been studied quantitatively by determining the LD 50 for this substance in normal and adrenalectomized rats, and in rats whose adrenals had been enucleated 2 months previously. 2. The LD50 for adrenalectomized rats is about one-fiftieth, and for enucleated rats greater than one-third of that for normal animals. The LD50 for adrenalectomized rats injected with 100 μg of adrenaline was similar to that of enucleated rats. 3. The administration of 100 μg of adrenaline to enucleated animals significantly increased their resistance to histamine, but did not bring it back to normal values; the difference between enucleated and normal rats thus appeared to be related, in part, at least, to the absence of the medullary secretion; no data are available to account for the rest of the difference.