0000000000039769
AUTHOR
Belen Cortina
Aspirin and COX-2 Inhibitor Nimesulide Potentiate Adrenergic Contractions of Human Gastroepiploic Artery
Background The aim of the present study was to evaluate the intervention of COX-1- and COX-2-derived prostaglandins in the responses of human gastroepiploic artery to sympathetic stimulation and norepinephrine. Methods Rings of human gastroepiploic artery were obtained from 45 patients (26 men and 19 women) undergoing gastrectomy. The rings were suspended in organ baths for isometric recording of tension. We studied the responses to electrical field stimulation, norepinephrine, and acetylcholine, in the absence and presence of COX-1 or COX-2 inhibition. Results The COX-1 and COX-2 inhibitor aspirin at high concentrations (10 −6 to 10 −5 mol/L) and the COX-2 inhibitor nimesulide (10 −6 mol/L…
Basal release of nitric oxide in the mesenteric artery in portal hypertension and cirrhosis: Role of dimethylarginine dimethylaminohydrolase
Background and Aim Increased basal release of nitric oxide (NO) in the splanchnic circulation contributes to elevated plasma levels of NO observed in decompensated cirrhosis. We evaluated in rat mesenteric arteries whether the differences in basal release of NO, revealed by asymmetric dimethylarginine (ADMA)- and NG-nitro-L-arginine methyl ester (L-NAME)-induced contractions, were associated with changes in messenger RNA (mRNA) expression of endothelial NO synthase (eNOS) and dimethylarginine dimethylaminohydrolases (DDAHs). Methods Rat small mesenteric arteries from 14 Sham-control, from 14 with partial portal vein ligation (PPVL), and from 14 with bile duct excision (BDE)-induced cirrhosi…
Effects of aspirin, nimesulide, and SC-560 on vasopressin-induced contraction of human gastroepiploic artery and saphenous vein.
Objective: The present experiments were designed to evaluate differences in the effects of cyclooxygenase (COX)-1 and COX-2 inhibition on contractile responses of human gastroepiploic artery and saphenous vein elicited by vasopressin. Design: Laboratory investigation. Setting: University laboratory. Subjects: Rings of human gastroepiploic artery were obtained from 32 patients undergoing gastrectomy, and rings of saphenous vein were obtained from 30 patients undergoing coronary artery bypass surgery. Interventions: The rings were suspended in organ baths for isometric recording of tension. We studied the responses to vasopressin in the absence and in the presence of either the vasopressin V …
Role of Ca2+-Activated K+ Channels on Adrenergic Responses of Human Saphenous Vein
Background We studied the participation of K + channels on the adrenergic responses in human saphenous veins as well as the intervention of dihydropyridine-sensitive Ca 2+ channels on modulation of adrenergic responses by K + channels blockade. Methods Saphenous vein rings were obtained from 40 patients undergoing coronary artery bypass surgery. The vein rings were suspended in organ bath chambers for isometric recording of tension. Results Iberiotoxin (10 −7 mol/L), an inhibitor of large conductance Ca 2+ -activated K + channels, and charybdotoxin (10 −7 mol/L), an inhibitor of both large and intermediate conductance Ca 2+ -activated K + channels, enhanced the contractions elicited by elec…
Effects of asymmetric dimethylarginine on renal arteries in portal hypertension and cirrhosis
AIM. To evaluate the effects of asymmetric dimethylarginine (ADMA) in renal arteries from portal hypertensive and cirrhotic rats. METHODS. Rat renal arteries from Sham (n = 15), pre-hepatic portal hypertension (PPVL; n = 15) and bile duct ligation and excision-induced cirrhosis (BDL; n = 15) were precontracted with norepinephrine, and additional contractions were induced with ADMA (10-6-10-3 mol/L), an endogenous inhibitor of nitric oxide (NO) synthase. Concentration-response curves to acetylcholine (1 × 10-9-3 × 10-6 mol/L) were determined in precontracted renal artery segments with norepinephrine in the absence and in the presence of ADMA. Kidneys were collected to determine the protein e…
Unchanged plasma levels of dimethylarginines and nitric oxide in chronic hepatitis C.
Previous studies have shown that asymmetric dimethylarginine (ADMA), symmetric dimethylarginine (SDMA) and nitric oxide (NO) play a prominent role in liver dysfunction. The objective of this study was to determine whether plasma levels of ADMA, SDMA and NO are altered in patients with chronic hepatitis C.Plasma levels of ADMA, SDMA and NO (nitrite plus nitrate) were measured in 22 patients with chronic hepatitis C and 24 patients with sustained virologic response after treatment with peginterferon plus ribavirin. Seven healthy volunteers served as controls.Plasma levels of ADMA, SDMA and NO were not significantly different between groups: chronic hepatitis C, ADMA 0.55+/-0.06, SDMA 0.22+/-0…