[Response of plasma catecholamine and PRA to i.v. injection of glucagon in upright posture after furosemide injection in essential hypertension (author's transl)].

To investigate the pathogenic role of the sympathetic nervous system and the renin-angiotensin system in essential hypertension, we evaluated plasma catecholamine and PRA levels after glucagon stimulation and during one hour in upright posture after i.v. injection of furosemide. In nine normal and high renin essential hypertensive (NHRH) subjects, i.v. injection of 1000 micrograms of glucagon caused rapid and significant increases in plasma epinephrine(E) concentration. Both the 5 min. level after glucagon injection (314 +/- 30 pg/ml, mean +/- S.E., p less than 0.05) and peak value (358 +/- 87 pg/ml, p less than 0.05) were significantly higher than the basal level(170 +/- 25 pg/ml). Plasma norepinephrine(NE) concentration of the peak value(1065 +/- 231 pg/ml) was significantly higher than the basal(357 +/- 50 pg/ml, p less than 0.02). PRA levels increased in 4 out of 9 patients. In seven patients with low renin essential hypertension(LRH), there was an impaired PRA response to glucagon, E also failed to increase at any time after glucagon injection, but peak value of NE(1212 +/- 274 pg/ml) was significantly higher than the basal level(391 +/- 77 pg/ml, p less than 0.01). NE level of NHRH during one hour in upright posture after i.v. injection of 40 mg of furosemide were higher than LRH. Particularly at 10 min. level, the NE level of NHRH(895 +/- 115 pg/ml) was significantly higher than LRH(523 +/- 91 pg/ml, p less than 0.05). These results suggest that the sympathetic-adrenomedullary function in LRH is diminished, and the renin secreting ability of JG cells is also diminished in LRH. The glucagon stimulation test is useful to assess renin secreting ability of JG cells.