RAT PINEALOCYTE REACTIVE RESPONSE TO A LONG-TERM STRESS INDUCEMENT

The pineal gland-reactive response to long-term multifactor stress ind ucement performed by 18 h immobilization was found in the occurrence o f different pinealocyte forms-cells of the basal activity, functionall y animated cells and cells assumed to be threatened by an irreversible injury. Functionally animated pinealocytes were recognized as entitie s of neuroendocrine-like and ependymal-like activities displaying an e pisode of their initially increased secretory activity determined by G olgi apparatus and succeeded by a period determined by the storage of compounds arising from the cisterns of the granular reticulum. The dom ination of the pinealocytes with neuroendocrine-like activity was cons idered to evince a stimulated, peptidergic-mediated pineal gland activ ity. The adrenocorticotropic hormone-reactive secretion, employed as t he evaluation parameter in morphofunctional observations, corroborated the morphologically estimated increased pineal gland activity in long -term stress inducement. Copyright (C) 1996 IBRO. Published by Elsevie r Science Ltd.