The Impact of Environmental and Psychological Stressors on Markers of Stress Axis Activation and the Beneficial Effects of Manual Therapy
Centrally-acting Pituitary adenylate cyclase-activating polypeptide (PACAP) is involved in hypothalamo-pituitary-adrenocortical (HPA) and sympatho-adrenal (SA) responses to stress. Evidence for an intra-adrenal PACAPergic system is mounting although information is lacking about its responsiveness to different stressors, especially as it compares to responses seen in other adrenal stress systems involving glucocorticoids and catecholamines. My work examines the impact of various physiological, psychological, and environmental stressors on markers of HPA and HSA activity in the adrenal gland and hypothalamus. Markers evaluated in these studies include mRNA expression of adrenal PACAP, steroidogenic acute regulatory protein (StAR), a chaperone protein crucial for making cholesterol available for the initiation of steroid biosynthesis and melanocortin receptor accessory protein (MRAP), essential for trafficking of the adrenocorticotropic hormone receptor, melanocortin 2 (MC2R), CA biosynthetic enzymes tyrosine hydroxylase (TH) , and phenylethanolamine N-methyltransferase (PNMT), which methylates norepinephrine to epinephrine. In addition, I attempted to place markers for altered gene expression within the context of current perceptions on the etiology of hypertension. Lastly, I developed a reproducible procedure for studying a possible non-invasive treatment for hypertension using the application of variable pressures during massage-like stroking in rats.