The spectrum of pressor-response to norepinephrine in normotensive and hypertensive patients.
The pressor-response to norepinephrine was determined in the whole body circulation of 15 normal subjects and 86 untreated essential hypertensive patients. The slope, the threshold-dose and the critical-dose were calculated from the log dose-response curve. In the overall population (101 subjects) a slight correlation (r = +0.20 less than 0.05) was observed between the basal diastolic arterial pressure and the threshold-dose. In contrast, highly significant parabolic correlations (r = +0.46 less than 0.00001) were observed between the diastolic arterial pressure and the slope or the critical dose. When diastolic arterial pressure was above 100 mmHg, the slope increased while the blood pressure increased. This result suggests either a decreased sympathetic tone or an adaptative structural change of the arterial wall. When diastolic arterial pressure was under 100 mmHg, the slope decreased while the blood pressure increased. This observation points to an enhanced sympathetic activity in mild blood pressure.
D000328:Adult; D001794:Blood Pressure / Q000187:drug effects*; D006801:Humans; D006973:Hypertension / Q000503:physiopathology*; D008297:Male; D009638:Norepinephrine / Q000494:pharmacology*
D009638:Norepinephrine