[Age-related reactions of the rat hypothalamo-hypophyseal neurosecretory system to physical load]

In two age groups of rats (5 to 6 months--young animals and 10 to 12 months--aging rats) the response of peptidergic Gomori-positive hypothalamic-hypophyseal neurosecretoryoryory (NS) system to moderate exercises (swimming during 30 minutes) was studied. The age differences in histology of NS centers and neurogemnic organs were found immediately after swimming and within 4 subsequent days. More rapid but less significant devastation of neurogemnic regions, combined with sharp intensification of the neurosecret synthesis in NS centers, was seen in the young animals. In the aging rats the response was slower, the neurosecret synthesis and its release from NS centers were not so activated. The anterocommissural group of the NS centers studied (especially in the young animals) and supraoptic nucleus were most closely associated with the response to exercises. The paraventricular nucleus was activated later, that appears to indicate the secondary inclusion of this NS center into elimination of the aftereffects of an upset balance.