Changes Of ACTH Cells In Part Distalis Of Pituitary Gland And SDH And 3β-HSD In Adrenal Cortex Of Rats After Traumatic Brain Injury

OBJECTIVES Stress is body's complicated reactions to every kinds of harmful stimulations (stressor), its basis is a series of body's neuroendocrine disturbance . Traumatic brain injury are most frequently found in all kinds of traumatic injury, and this injury can induce changes of body's neuroendocrine systems, for example,the activation of several endocrinal axis of hypothalamus. Among all these changes, the activation of Hypothalamus-Pituit-ary-Adrenal axis (HPA axis) and the secretion of glucocorticoid (GC) are most important. At present, there are some reports about the research of the changes of HPA axis after traumatic brain injury, but these reports mainly laid particular emphasis on the aspect of physiological function, there aren't any reports discussing the changes of pituitary-adrenal axis of rats after traumatic brain injury from the aspects of pathomorphology using immuneo-histochemical and histochemical methods up to now. So, this research mainly discussed the functional changes of HPA axis of rats after traumatic brain injury by observing the changes of adrenocorticotropic hormone ( ACTH ) cells in part distalis of pituitary gland and succinate dehydrogenase ( SDH ) and 3 -hydroxysteroid dehydrogenase (3 -HSD ) in adrenal cortex from the aspects of pathomorphology. and this research can alsohelp clinical treatments of patients suffering traumatic brain injury.METHODS 30 male Wistar rats were divided into 3 group randomly, i.e. control group, 1 day (after traumatic brain injury) group and 7 day (after traumatic brain injury) group. Rats of the test group were traumatically-brained injuried on the left side of the brains using dropping-weight-method, while the rats of the control group were only windowed on the left cranial bones, the same position as the rats of the 1 day and 7 day groups. All these rats" heads were cut off after cranial bone windowed, 1 day and 7 days after traumatically-brained injuried, respectively, then All these rats" pituitary glands were taken out, fixed with 10% neutral formaldehyde solution Liquid, sectioned using usual paraffin method, and stained using immunohistochemical method. All these rats' adrenal glands were taken out respectively, frozen in nitrogen liquid (-196 ), sectioned in cryostat, stained using histochemical method. The morphological and functional changes of pituitary-adrenal axis during traumatic brain injury and recovery after injury were analyzed using image-analysis method.RESULTS 1. the staining of ACTH cells using immunohistochemical method showed: the mean optic density (MOD) values and the square density (SD) values of positive ACTH cells in rats of 1 day group are significantly higher than those of control group (P<0.01). those of 1 day group are significantly higher than 7 day group (P<0.01), and there isn't significantly different between those of the control group and 7 day group (P>0.05). 2. the staining of 3 -HSD and SDH of adrenal cortex cells usinghistochemical method showed: MOD values of 3 β -HSD and SDH of adrenal cortex cells of 1 day group are significantly higher than those of control group (P<0.01). those of 1 day group are significantly higher than 7 day group (P<0.05), and. there isn't significantly different between the control group and 7 day group (P>0.05).CONCLUSIONS The research testified from the aspects of pathomorphology that traumatic brain injury could make ACTH cells of part distalis of pituitary gland and adrenal cortex of rats function more, and during the recovery course these cells' function will recover gradually to normal.