0000000000642651
AUTHOR
Gloria Vicenta Segarra Irles
Contractile responses of human thyroid arteries to vasopressin
Aims: In the present study we investigated the intervention of nitric oxide and prostacyclin in the responses to vasopressin of isolated thyroid arteries obtained from multi-organ donors. Main methods: Paired artery rings from glandular branches of the superior thyroid artery, one normal and the other deendothelised, were mounted in organ baths for isometric recording of tension. Concentration-response curves to vasopressin were determined in the absence and in the presence of either the vasopressin V1 receptor antagonist d(CH2)5Tyr(Me)AVP (10−8 M), the nitric oxide synthase inhibitor NG-monomethyl-Larginine (L-NMMA, 10−4 M), or the inhibitor of prostaglandins indomethacin (10−6 M). Key fin…
Aging enhances contraction to thromboxane A2 in aorta from female senescence mice
The time-course for aging-associated effects on vascular reactivity to U46619, a stable analogue of thromboxane A2 (TXA2), was studied in aorta from female senescence-accelerated mice-prone (SAMP8), a murine model of accelerated senescence. SAMP8 and senescence-accelerated mice-resistant (SAMR1) were divided into three groups: 3-, 6- and 10-month-old. Contractile curves to U46619 (10−9 to 10−6 M) were performed in aortic rings in the absence or in the presence of nitric oxide synthase (NOS) inhibitor NG-nitro-L-arginine methyl ester (L-NAME; 10−4 M) and/or cyclooxygenase (COX) inhibitor indomethacin (10−5 M). Protein and gene expression for COX-1 and COX-2 were determined by immunofluoresce…
Modulation of adrenergic responses of human vas deferens by K+ channel inhibitors
The results suggest that charybdotoxin-sensitive, but iberiotoxin-insensitive, K+ channels are activated by stimulation with norepinephrine and electrical field stimulation to counteract the adrenergic-induced contractions of human vas deferens. Thus, inhibition of these channels increases significantly the contraction, an effect that appears to be mediated by an increase in Ca2+ entry through L-type voltage-dependent Ca2+ channels.
Nitric oxide mediates abnormal responsiveness of thyroid arteries in methimazole-treated patients
Objective: We studied the intervention of nitric oxide (NO), prostacyclin (PGI2) and endothelium-derived hyperpolarizing factor (EDHF) in mediating responses to acetylcholine in thyroid arteries from euthyroid (E) and methimazole-treated (MT) patients. Design and methods: Branches of the superior thyroid artery were obtained from 19 E patients and 17 MT patients (euthyroid at the time of surgery) undergoing total thyroidectomy or hemithyroidectomy. Artery rings were suspended in organ baths for isometric recording of tension. Results and conclusions: Acetylcholine caused endothelium-dependent relaxation of greater magnitude in arteries from MT patients (pD2 7.68±0.19 in E and 8.17±0.26 in M…
Accumulation of symetric dimethylarginine in hepatorenal syndrome.
In patients with cirrhosis, nitric oxide (NO), asymmetric dimethylarginine (ADMA), and possibly symmetric dimethylarginine (SDMA) have been linked to the severity of the disease. We investigated whether plasma levels of dimethylarginines and NO are elevated in patients with hepatorenal syndrome (HRS), compared with patients with cirrhosis without renal failure (no- HRS). Plasma levels of NO, ADMA, SDMA, and L-arginine were measured in 11 patients with HRS, seven patients with no-HRS, and six healthy volunteers. SDMA concentration in HRS was higher than in no-HRS and healthy subjects (1.47 6 0.25 vs. 0.38 6 0.06 and 0.29 6 0.04 lM, respectively; P , 0.05). ADMA and NOx concentrations were hi…