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Biomedical subjects

V DeQuattro

Publications and source records attributed to V DeQuattro.

96 records · Page 6Linked to original sources
PubMed1968

Catecholamine turnover in normotensive and hypertensive man: effects of antiadrenergic drugs.

Intravenous administration of tritium-labeled 3,4-dihydroxyphenylalanine (dopa) to human subjects resulted in the labeling of endogenous catecholamines and vanillylmandelic acid (VMA). Determination of the changes in specific activity of these compounds with time in fractional collections of urine and in cardiac biopsies from patients undergoing corrective cardiac surgery permitted estimation of apparent turnover rates. The average half-time of the exponential decline in specific activity of labeled urinary norepinephrine was about 8 hr and that of VMA was 11-16 hr in five normal subjects. No significant differences from normal were observed in eight patients with essential hypertension. The average half-life of norepinephrine was only 5 hr in cardiac patients undergoing surgery, and the levels and rate of decline of cardiac norepinephrine specific activity correlated well with the exponential phase of the urinary disappearance curve. There were significant effects of treatment with alpha-methyltyrosine, reserpine, and pargyline hydrochloride on the labeling and apparent turnover rates of norepinephrine and VMA; the effects noted were consistent with known actions of these three drugs. It is suggested that the technique used is a suitable means of assessing "over-all" catecholamine metabolism in man, particulary if combined with quantitative assay of urinary catecholamine metabolites.

Adolescent↗
PubMedDate not supplied

Increased hypothalamic noradrenergic activity in one-kidney, one-clip renovascular hypertensive rats.

To further define central and peripheral sympathetic nerve activity in the one-kidney and two-kidney, one-clip models of renovascular hypertension, plasma catecholamines and regional brain norepinephrine of these models were compared with the activities of their brain biosynthetic enzymes: tyrosine hydroxylase (TYH) and dopamine-beta-hydroxylase (DBH). Findings in the groups of 20 one-kidney and 17 two-kidney female Wistar rats were compared with those in 10 sham-operated rats. Systolic blood pressure, measured indirectly, and the mean arterial pressure, measured directly from the femoral arteries, verified development of renovascular hypertension in both the one and two-kidney animals. Plasma norepinephrine increased from 248 +/- 46 to 401 +/- 66 pg/ml in the one-kidney group only (p < 0.001). Hypothalamic TYH and DBH activities of the one-kidney animals were 48 and 34% greater than those of the two-kidney animals and 28 and 39% greater than the sham-operated animals. The multiple t-test indicated significant differences between the mean hypothalamic THY of the one- and two-kidney groups and between the hypothalamic DBH of the one-kidney animals and those of the two-kidney and sham groups (alpha = 0.05). Moreover, the mean norepinephrine content of the hypothalamus in the one-kidney animals was 66% greater than that of the two-kidney and sham groups (p < 0.05). These findings suggest that central noradrenergic pathways of the hypothalamus may be involved in the genesis of one-kidney renovascular hypertension.

Animals↗
PubMedDate not supplied

Anxiety, anger, and neurogenic tone at rest and in stress in patients with primary hypertension.

To determine whether basal blood pressure or pressor responses to stress are related to sympathetic nerve tone or to psychological factors in hypertensives, 15 hypertensives and 13 normotensives were studied by mean of a self-administered questionnaire, isometric handgrip exercise (IHE), and the mental stress of serial subtraction. Plasma norepinephrine (NE), epinephrine (E), blood pressure (BP) and heart rate (HR) were measured before and at the end of IHE and mental stress. A greater number of hypertensives had suppressed anger (p less than 0.01) and scored higher on anxiety trait (p less than 0.01) and depression (p less than 0.05). Prestress (IHE and mental) BP and NE values were significantly greater in hypertensives (all p less than 0.01). During IHE, both groups had a significant increase of BP, HR, and NE (all p less than 0.01) but E rose in hypertensives only (p less than 0.05). The percentage change of BP, HR, NE, and E during IHE was similar in both groups. The changes of BP and HR were not related to NE or E. During mental stress, HR (p less than 0.01) and E (p less than 0.05) increased in both groups. However, BP (systolic and diastolic) increased in normotensives only (p less than 0.01). Plasma NE contents were unchanged in both groups. There were significant positive correlations of anxiety trait with systolic BP (p less than 0.05), diastolic BP (p less than 0.05), and NE (p less than 0.05) and E (p less than 0.05). Although hypertensives had increased neurogenic tone related perhaps to inward anger and anxiety, the percentage responses of neurogenic tone and BP to IHE were equivalent to those of normotensives. The challenge of serial subtraction did not elicit further noradrenergic or pressor responses in hypertensives. Suppressed anger and anxiety, via increased basal neurogenic tone, may be pathogenic factors in some patients with primary hypertension.

Adult↗