[Changes in the dimensions of cells and their nuclei in the adrenal medullary substance of white rats during acute overheating].

It has been shown for the first time that the size of adrenocytes and of their nuclei does not change in the adrenal medulla on the state of motor excitation, and decreases at the heat stroke under conditions of acute overheating. According to Bennighoff (1950), the decrease of nuclear volume suggests the weakness of the adrenocyte secretory activity. But in reality the specific activity of adrenocytes may increase at hyperthermy, which contradicts to the hypothesis in question. Such a contradiction may be explained by the fact of adrenocyte dehydration under the influence of the external heat. It may result in a decrease in the nuclear volume irrespective of the functional state of the nuclei. The secretory activity of adrenocytes can be evaluated on the basis of the changed relation in the nuclear number of varying volume corresponding to different steps of the secretory cycle.