Central and peripheral sympathetic characteristics in hypertension considered from differences of catecholamine metabolite concentrations in plasma before and after adrenalectomy in male 2-month-old SHRSP and WKY

摘要

To clarify the detailed role of the adrenal medulla in 2-month-old SHRSP, the catecholamine concentrations in the plasma before and after bilateral adrenalectomy (Adrex) were measured with Neurochemo-HPLC system comparing with normotensive WKY. L-dopa, 3-OMDOPA (3-o-methyl-dopa), HVA (homovanillic acid), NE (norepinephrine) levels were not different between before and after Adrex in both of SHRSP and WKY. MHPG (3,4-methoxy-hydroxyphenyt glycol) and VA (vanillic acid) levels in WKY were not changed by Adrex except lower levels as compared with SHRSP, while those in SHRSP were remarkably decreased by Adrex. On the other hand, Ep (epinephrine) and MN (metanephrine) levels tended to decrease in WKY, and to increase in SHRSP after Adrex. Blood pressures were not changed by Adrex in either rat group. These findings indicate that (1) almost all of the MHPG and VA in blood are released from the adrenal glands in SHRSP; (2) the final catecholamine products of E and MN must be secreted by larger quantities of release from the accessory adrenal glands or extra-adrenal glands mainly in SHRSP than original release from the adrenal glands; and (3) as a result, the blood pressure might not be affected by Adrex in either SHRSP or WKY.