Circulating levels of catecholamines and cyclic AMP during the handgrip test in borderline hypertension.

Systolic and diastolic blood pressure, heart rate, and circulating levels of catecholamines and cyclic AMP were measured during the handgrip test in 18 borderline hypertensive patients, 22 stable hypertensive patients, and 20 normotensive control subjects. No difference was observed, at rest, for plasma levels of noradrenaline, adrenaline, dopamine, and cyclic AMP among the three groups. During the handgrip test in borderline hypertensive patients, the percentage of increase of plasma levels of noradrenaline, adrenaline, dopamine, and cyclic AMP were significantly more elevated with respect to the levels of control subjects but not when compared with those of stable hypertensive patients. These results are in agreement with the hypothesis that in both borderline and stable hypertension there is an exaggerated sympathetic response to the handgrip test.

AIDS-like immunologic alterations in clinically unaffected drug users.

Peripheral blood lymphocyte subpopulations (PBLS) and HLA-DR phenotype have been evaluated in 30 IV drug users who were not affected by acquired immune deficiency syndrome (AIDS). A strongly significant reduction in helper/suppressor ratio was found in these subjects as compared to the control population. When the group under study was subdivided according to the presence or absence of signs of lymphadenopathy syndrome (LAS), the apparently unaffected individuals still had significant modifications in PBLS when compared with controls. These modifications were more marked in subjects within the LAS+ subgroup, who also showed a greater DR5 frequency than those belonging to the LAS- subgroup. The authors concluded that AIDS-like laboratory alterations are present in clinically unaffected IV drug users; the possible role of DR5 in conditioning different individual susceptibility is considered.

Blood pressure effects of acute hypercalcemia in normal subjects and thyroparathyroidectomized patients.

The effect of acute hypercalcemia on blood pressure and plasma catecholamine levels was investigated in 10 normal subjects and in 5 patients completely thyroparathyroidectomized (TPTX) for a parathyroid cancer. In normal subjects, calcium infusion (15 mg/kg over 3 h) significantly increased plasma calcium and epinephrine levels and blood pressure. Plasma norepinephrine was increased only after 3 h of calcium infusion. In TPTX patients, calcium infusion increased significantly plasma calcium and epinephrine but not blood pressure. The percent increase in mean blood pressure during calcium infusion correlated with the concomitant percent increase in serum calcium in normal subjects (r = 0.71, p less than 0.001) but not in TPTX patients (r = -0.08). These data are in agreement with the hypothesis that the effect of calcium on arterial pressure is realized under intact parathyroid function.