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

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