Preliminary communication on intralymphocyte ionized magnesium in hypertensive patients under treatment with beta-blockers.
We measured free intralymphocyte magnesium (Mgi) in 10 hypertensive subjects (HS) before and after treatment with atenolol (A) and in 16 normotensive control subjects (NC). We also carried out in vitro studies on human lymphocytes to test the effect of catecholamines and beta-antagonists on Mgi. Mgi in HS was not statistically different before and after the treatment with A (M +/- SD, basal: 227 +/- 31 + mumol/l; A: 236 +/- 47 mumol/l; NS). Mgi in NC proved not statistically different as compared to HS without treatment (M +/- SD, NC: 232 +/- 35 mumol/l; HS before treatment: 227 +/- 31 mumol/l; NS). The Mgi of the lymphocytes treated in vitro with noradrenaline (NA) significantly decreased in comparison with the control (M +/- SD, basal: 244 +/- 26 mumol/l; NA: 198 +/- 25 mumol/l; p = 0.0001), whereas it did not change after incubation with NA and propranolol (P) (M +/- SD, basal: 238 +/- 32 mumol/l; NA + P: 239 +/- 30 mumol/l; NS). On the other hand Mgi decreased significantly after incubation with NA and A (M +/- SD, basal: 255 +/- 21 mumol/l; NA + A: 202 +/- 34 mumol/l). Our in vivo data show that the Mgi of HS remains unvaried after treatment with A, and that there is not statistical difference between Mgi of NC and of HS before treatment. The in vitro study demonstrated that catecholamines cause a significant reduction in Mgi. This effect is only inhibited by a non-selective beta-blocker such as P. These results seem to explain the ineffectiveness of treatment with atenolol on our patients' Mgi.
Pastori
C
C
Institute of Internal Medicine, University of Verona, Italy.
Delva
P
P
Degan
M
M
Lechi
A
A
D000316:Adrenergic alpha-Agonists / Q000494:pharmacology; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology* / Q000627:therapeutic use; D000328:Adult; D001262:Atenolol / Q000494:pharmacology; D002118:Calcium / Q000097:blood / Q000378:metabolism; D005260:Female; D006801:Humans; D006973:Hypertension / Q000188:drug therapy / Q000378:metabolism*; D008214:Lymphocytes / Q000378:metabolism*; D008274:Magnesium / Q000097:blood / Q000378:metabolism*; D008297:Male; D009638:Norepinephrine / Q000494:pharmacology; D011433:Propranolol / Q000494:pharmacology
D000316:Adrenergic alpha-Agonists; D000319:Adrenergic beta-Antagonists; D001262:Atenolol; D011433:Propranolol; D008274:Magnesium; D002118:Calcium; D009638:Norepinephrine