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F37. Involvement of sympathetic vasoconstriction in L-name induced hypertension in conscious rats
Vol. 32, Nos. 2-3
Free Communications
237
F37. INVOLVEMENT OF SYMPATHETIC VASOCONSTRICTION IN L-NAME INDUCED H Y P E R T E N S I O N IN C O N S C I O U S RATS N. IIDA Department of Physiology, School of Medicine, University of Hiroshima, Minarni-ku, Hiroshima 734, Japan The aims of the study are: (1) to d e t e r m i n e w h e t h e r sympathetic vasoconstriction is involved in L-NAME (inhibitor of NO synthase) induced hypertension in conscious rats, and (2) to understand whether or not the abnormal tone caused in peripheral vascular beds is of spinal origin. For these purposes, we studied the effects of ganglion blockade hexamethonium (C6) and L-arginine on L-NAME induced hypertension in intact and spinal rats. Spinal transection was performed at Thoracic 1 in ether-anesthetized rats with an electromagnetic flow probe placed around the superior mesenteric artery, renal artery or terminal aorta, and a catheter in the jugular vein for drug application. Peripheral resistance was calculated by dividing arterial pressure by peripheral blood flow. Three or 4 days after operation, regional blood flow and arterial pressure were measured in the conscious, resting state. L-NAME injection (3-5 m g / k g iv) resulted in a significant increase in mean arterial pressure and peripheral vascular resistances in both intact and spinal rats. Ten minutes after L-NAME injection, the infusion of C6 (25 m g / k g iv) reduced arterial pressure and peripheral vascular resistances significantly, while hindquarter resistance did not decrease significantly in spinal rats. Mesenteric resistance returned to the control level with further bolus injection of Larginine (70 m g / k g iv), but renal and hindquarter resistances returned only partially. These results suggest that L-NAME induced hypertension is partially mediated by sympathetic vasoconstriction and the abnormal tones elicited in the superior mesenteric and renal areas are of spinal origin, while hindquarter tone may be of supraspinal origin, but is mediated also by a regional mechanism.
FREE COMMUNICATIONS 38-56; METHODOLOGY F38. A U T O M A T E D IMAGE P R O C E S S I N G SYSTEM F O R SHAPE RECOGNITION OF SINGLE RED BLOOD CEIJ.S BASED ON
OUT-OF-FOCUS
IMAGES
G. SCHNEIDER, G. ARTMANN AND G. H E N N I N G Department of Applied Cell Biophysics, FH Aachen, D-52429 Jfilich, Germany Shape recognition of red blood cells (RBC), including detection of subpopulations, is quite important in diagnosis. Apart from characteristic shape distribution due to different diseases, the shape response caused by (cell damaging) substances is a focus of interest. Automated procedures presently known can't classify single RBC, but only calculate an integral shape parameter of the whole blood sample. Additionally, calibration to a normal set of cells is required. Here, a technique is presented, which allows single classification of
Free Communications
237
F37. INVOLVEMENT OF SYMPATHETIC VASOCONSTRICTION IN L-NAME INDUCED H Y P E R T E N S I O N IN C O N S C I O U S RATS N. IIDA Department of Physiology, School of Medicine, University of Hiroshima, Minarni-ku, Hiroshima 734, Japan The aims of the study are: (1) to d e t e r m i n e w h e t h e r sympathetic vasoconstriction is involved in L-NAME (inhibitor of NO synthase) induced hypertension in conscious rats, and (2) to understand whether or not the abnormal tone caused in peripheral vascular beds is of spinal origin. For these purposes, we studied the effects of ganglion blockade hexamethonium (C6) and L-arginine on L-NAME induced hypertension in intact and spinal rats. Spinal transection was performed at Thoracic 1 in ether-anesthetized rats with an electromagnetic flow probe placed around the superior mesenteric artery, renal artery or terminal aorta, and a catheter in the jugular vein for drug application. Peripheral resistance was calculated by dividing arterial pressure by peripheral blood flow. Three or 4 days after operation, regional blood flow and arterial pressure were measured in the conscious, resting state. L-NAME injection (3-5 m g / k g iv) resulted in a significant increase in mean arterial pressure and peripheral vascular resistances in both intact and spinal rats. Ten minutes after L-NAME injection, the infusion of C6 (25 m g / k g iv) reduced arterial pressure and peripheral vascular resistances significantly, while hindquarter resistance did not decrease significantly in spinal rats. Mesenteric resistance returned to the control level with further bolus injection of Larginine (70 m g / k g iv), but renal and hindquarter resistances returned only partially. These results suggest that L-NAME induced hypertension is partially mediated by sympathetic vasoconstriction and the abnormal tones elicited in the superior mesenteric and renal areas are of spinal origin, while hindquarter tone may be of supraspinal origin, but is mediated also by a regional mechanism.
FREE COMMUNICATIONS 38-56; METHODOLOGY F38. A U T O M A T E D IMAGE P R O C E S S I N G SYSTEM F O R SHAPE RECOGNITION OF SINGLE RED BLOOD CEIJ.S BASED ON
OUT-OF-FOCUS
IMAGES
G. SCHNEIDER, G. ARTMANN AND G. H E N N I N G Department of Applied Cell Biophysics, FH Aachen, D-52429 Jfilich, Germany Shape recognition of red blood cells (RBC), including detection of subpopulations, is quite important in diagnosis. Apart from characteristic shape distribution due to different diseases, the shape response caused by (cell damaging) substances is a focus of interest. Automated procedures presently known can't classify single RBC, but only calculate an integral shape parameter of the whole blood sample. Additionally, calibration to a normal set of cells is required. Here, a technique is presented, which allows single classification of