40 research outputs found
Study of Heparin in Intestinal Ischemia and Reperfusion in Rats: Morphologic and Functional Evaluation
AbstractTo study whether treatment with heparin (HEP) attenuates intestinal dysfunction caused by ischemia (I) and reperfusion (R), rats were treated with HEP (100 U/kg intravenously) or saline solution (SS) before I (60 min), which was produced by occlusion of the superior mesenteric artery, and R (120 min). After I or I/R, we mounted 2-cm jejunal segment in an organ bath to study neurogenic contractions stimulated by electrical pulses or KCl, using a digital recording system. Thin jejunal slices were stained with hematoxylin and eosin for optical microscopy. Compared with the sham group, jejunal contractions were similar in the I + HEP and the I/R + HEP groups, but reduced in the I + SS and the I/R + SS groups. The jejunal enteric nerves were damaged in the I + SS and the I/R + SS, but not in the I + HEP and the I/R + HEP cohorts. These results suggested that HEP attenuated intestinal dysfunction caused by I and I/R
Study of Heparin in Intestinal Ischemia and Reperfusion in Rats: Morphologic and Functional Evaluation
To study whether treatment with heparin (HEP) attenuates intestinal dysfunction caused by ischemia (I) and reperfusion (R), rats were treated with HEP (100 U/kg intravenously) or saline solution (SS) before I (60 min), which was produced by occlusion of the superior mesenteric artery, and R (120 min). After I or I/R, we mounted 2-cm jejunal segment in an organ bath to study neurogenic contractions stimulated by electrical pulses or KCl, using a digital recording system. Thin jejunal slices were stained with hematoxylin and eosin for optical microscopy. Compared with the sham group, jejunal contractions were similar in the I + HEP and the I/R + HEP groups, but reduced in the I + SS and the I/R + SS groups. the jejunal enteric nerves were damaged in the I + SS and the I/R + SS, but not in the I + HEP and the I/R + HEP cohorts. These results suggested that HEP attenuated intestinal dysfunction caused by I and I/R.Universidade Federal de São Paulo, Escola Paulista Med, Dept Surg, BR-04023900 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Pharmacol, BR-04023900 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Biochem, BR-04023900 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Morphol, BR-04023900 São Paulo, BrazilFed Univ Great Dourados, Sch Med, Dourados, BrazilUniversidade Federal de São Paulo, Escola Paulista Med, Dept Surg, BR-04023900 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Pharmacol, BR-04023900 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Biochem, BR-04023900 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Morphol, BR-04023900 São Paulo, BrazilWeb of Scienc
Functionomics: the analysis of a postgenomic concept on the basis of pregenomic pharmacological studies in smooth muscle
Ischemic preconditioning and the gene expression of enteric endothelial cell biology of rats submitted to intestinal ischemia and reperfusion
Effect of atenolol pre-treatment in heart damage in a model of intestinal ischemia-reperfusion
Increased density of alpha-adrenoceptors in vas-deferens of spontaneously hypertensive rats (SHR), indicated by functional and receptor-binding studies
Pharmacological parameters were determined from contractile responses mediated by alpha-adrenoceptors in vas deferens from spontaneously hypertensive rats (SHR) and corresponding normotensive controls, Wistar Kyoto rats (WKY), and compared with data obtained from radioligand binding assays. Contractile responses induced in longitudinal and circular muscle layers by the alpha-adrenoceptor agonist noradrenaline (NA) and by barium chloride were recorded as described previously. in both muscle layers the maximal effects induced by NA, but not by BaCl2, were significantly greater in SHR. As a consequence, the relative responsiveness ratio (rho) for the alpha-adrenoceptor was also larger for SHR than for WKY. NA-induced contractions of both muscle layers were competitively antagonized by indoramine. the pA2 values for indoramine and pD2 values for NA were the same in SHR and WKY, indicating that alpha-adrenoceptor affinity was not changed in SHR. Additionally, binding studies with thc alpha-adrenoceptor ligand [H-3]WB4101 revealed that B(max) values were greater in the vas deferens of SHR, whereas K(d) values were not significantly different from those of WKY controls. in summary, although differences could not be detected for affinity-related parameters, a greater density of alpha-adrenoceptors was shown for SHR in receptor binding studies and this was corroborated by functional studies.ESCOLA PAULISTA MED SCH,DEPT PHARMACOL,CAIXA POSTAL 20372,BR-04034 São Paulo,BRAZILESCOLA PAULISTA MED SCH,DEPT PHARMACOL,CAIXA POSTAL 20372,BR-04034 São Paulo,BRAZILWeb of Scienc
Down-regulation of Na+/K+-ATPase alpha(2) isoform in denervated rat vas deferens
In the rat vas deferens, an organ richly innervated by peripheral sympathetic neurons, we have demonstrated recently the expression of alpha(1) and alpha(2), but not alpha(3) isoforms of the a subunit of Na+/K+-ATPase (EC 3.6.1.37), a membrane-bound enzyme of vital function for living cells (Noel et al., Biochem Pharmacol 55: 1531-1535, 1998). in the present work, we characterized, qualitatively and quantitatively, Na+/K+-ATPase a isoforms in denervated rat vasa deferentia. [H-3]Ouabain binding at concentrations defined for high-affinity isoforms (alpha(2) and/or alpha(3)) detected only one class of specific binding sites in control (C) and denervated (D) vas deferens. Although the dissociation constant was similar for both groups [K-d = 138 +/- 14 nM (C) and 125 +/- 8 nM (D)], a marked decrease in density was observed after denervation [716 +/- 81 fmol(.)mg protein(-1) (C) and 445 +/- 34 fmol(.)mg protein(-1) (D), P < 0.05]. in addition, western blotting revealed that denervated vasa deferentia produce the alpha(1) and alpha(2) isoforms but not alpha(3), just as we reported for the controls previously (Noel et al., Biochem Pharmacol 55: 1531-1535, 1998). Densitometric analysis showed a decrease of the alpha(2) isoform by about 4094 in denervated organs, in very good agreement with what was shown with the [H-3]ouabain binding technique, but no significant change in oil isoform density. Truncated alpha(1) (alpha(1)T), an isoform suggested to exist in the guinea pig vas deferens, was not detected. Altogether, our results demonstrated that Na+/K+-ATPase alpha(2) is down-regulated after sympathetic denervation of the rat vas deferens. (C) 2000 Elsevier Science Inc.Univ Fed Rio de Janeiro, Inst Ciencias Biomed, Dept Farmacol Basica & Clin, BR-21941590 Rio de Janeiro, BrazilUniversidade Federal de São Paulo, Dept Farmacol, Escola Paulista Med, BR-04034970 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Farmacol, Escola Paulista Med, BR-04034970 São Paulo, BrazilWeb of Scienc
Autonomic dysfunction of rat jejunum submitted to cold ischemic preservation is prevented by heparin
Previous studies suggest that cold ischemic preservation (CIP) employed in small bowel transplantation promotes loss of intestinal motility due to severe lesions in autonomic enteric nerves. This autonomic dysfunction may be prevented by antioxidant agents. in this work, we investigated whether preservation with heparin prevented autonomic dysfunction of rat jejunum submitted to CIP for a long time. Jejunal segments (2 cm) of Wistar rats (12 to 16 weeks old) were preserved at 4 degrees C in Ringer's lactate solution without (-) or with (+) 100 UI/mL heparin (H). After preservation for 12 hours, H+ and H- preparations were mounted in parallel in isolated organ baths containing 10 mL Tyrode's solution at 37 degrees C for the study of neurogenic contractions evoked by electrical field stimulation (EFS; 10-30 Hz, 1-ms duration, 60 V) or by stimulation of nicotinic (NIC) or muscarinic (carbachol, CCh) cholinoceptors. the effects of NIC (hexamethonium, HEX) and muscarinic (atropine, ATR) antagonists were studied on these contractions. Contractions induced by EFS (30 Hz) were four times greater in H+ (1.02 +/- 0.12 g) versus H- (0.26 +/- 0.07 g), while contractions induced by NIC (I mmol/L) were also four times higher in H+ (1.07 +/- 0.10 g) than H(0.25 +/- 0.09 g) preparations. in addition, contractions induced by CCh (1 mmol/L) were two times higher in H+ (1.21 +/- 0.13 g) than in H- (0.65 +/- 0.10 g). EFS, NIC, and CCh contractions were inhibited by pretreatment of jejunum with HEX or ATR (1 mu mol/L/30 min), in H+ and H-. These results indicated that addition of heparin to a preservation solution attenuated the autonomic dysfunction of rat jejunum submitted to CIP for a long time.Universidade Federal de São Paulo, Escola Paulista Med, Dept Surg, BR-04023900 São Paulo, BrazilUniversidade Federal de São Paulo, Escola Paulista Med, Dept Pharmacol, BR-04023900 São Paulo, BrazilUniversidade Federal de São Paulo, Escola Paulista Med, Dept Surg, BR-04023900 São Paulo, BrazilUniversidade Federal de São Paulo, Escola Paulista Med, Dept Pharmacol, BR-04023900 São Paulo, BrazilWeb of Scienc