RESUMO
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 (1 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 mumol/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.
Assuntos
Doenças do Sistema Nervoso Autônomo/etiologia , Doenças do Sistema Nervoso Autônomo/prevenção & controle , Heparina/uso terapêutico , Jejuno/inervação , Preservação de Órgãos/efeitos adversos , Animais , Modelos Animais , Músculo Liso/inervação , Ratos , Traumatismo por Reperfusão/prevenção & controleRESUMO
In vitro studies have demonstrated that cold ischemic preservation (CIP) employed in small bowel transplantation produces loss of intestinal motility due to severe lesions of autonomic enteric nerves and that this autonomic dysfunction is attenuated by antioxidant agents. In this work, we investigated whether preservation with atenolol attenuated autonomic dysfunction of rat jejunum submitted to long-term CIP. Jejunal segments (2 cm) of Wistar rats (12 to 16 weeks old) were surgically isolated and preserved at 4 degrees C in Ringer's lactate solution without (-) or with (+) 1 mumol/L atenolol (AT). After preservation for 12 hours, AT+ and AT- 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 to 30 Hz, 1-ms duration, 60 V) or by stimulation with nicotinic (nicotine, NIC) or muscarinic (carbachol, CCh) cholinoceptor agents as well as nicotine (hexamethonium, HEX) and muscarinic (atropine, ATR) antagonists. Contractions induced by EFS (30 Hz) were 46% higher in AT+ (0.38 +/- 0.02 g) than AT- (0.26 +/- 0.01 g), while contractions induced by NIC (1 mmol/L) were 84% higher in AT+ (0.46 +/- 0.03 g) than in AT- (0.25 +/- 0.02 g). In addition, contractions induced by CCh (1 mmol/L) were 34% higher in AT+ (0.87 +/- 0.06 g) than in AT- (0.65 +/- 0.08 g). EFS-, NIC-, and CCh-induced contractions were inhibited by pretreatment of jejunum with HEX or ATR (1 mumol/30 min), in AT+ and AT-. These results suggest that addition of atenolol in the preservation solution attenuated autonomic dysfunction of rat jejunum submitted to long-term CIP.