The application of Compont gel in chronic obstructive jaundice rats model

Purpose: To establish a new rat model, the pathogenesis of which is closer to the clinical occurrence of chronic obstructive jaundice with liver fibrosis. Methods: 90 SD rats were randomly divided into 3 groups. Group A common bile duct ligation, group B common bile duct injection compont and group C injection saline. The serum of three groups was extracted, and the liver function was detected by ELISA. HE staining, Masson staining and immunohistochemistry were used to detect liver pathology. Results: Group B showed a fluctuant development of jaundice, obstructive degree reached a peak at 2 weeks, and decreased from 3 weeks. HA, LA and PCIII were significantly higher than control group. 3 weeks after surgery, liver tissue fibrosis occurred in group B, and a wide range of fiber spacing was formed at 5 weeks. Immunohistochemistry showed that hepatic stellate cells were more active than the control group. Conclusion: Intra-biliary injection of Compont gel is different from the classic obstructive jaundice animal model caused by classic bile duct ligation, which can provide an ideal rat model of chronic obstructive jaundice with liver fibrosis.(AU)

Influence of indomethacin on effects of endothelin-1 on guinea pig isolated rings of common bile duct and sphincter of Oddi.

The effects of endothelin-1 on motility of guinea pig extra-hepatic biliary tract portions were studied. Endothelin-1 (< or =100 nM) failed to contract rings of hepatic, cystic, proximal or distal common bile ducts, or choledochal or papillary halves of sphincter of Oddi. At 100 nM, endothelin-1 or sarafotoxin S6c (selective endothelin ET(B) receptor agonist) inhibited contractions of choledochal (but not papillary) sphincter of Oddi to carbachol (1 microM) by 63+/-5 and 45+/-9%, respectively. In distal common bile duct, indomethacin (5.6 microM) unmasked potent contractile effects of endothelin-1 [EC(50) 7.8 (5.5-11.1) nM; E(MAX) 80+/-6% of response to 80 mM KCl] and enhanced the contractile potency of carbachol (585-fold at EC(50) level), but not cholecystokinin C-terminal octapeptide. Inhibition of cholinergic responsiveness of the choledochal sphincter of Oddi by endothelin-1 was reduced by BQ-123 (1 microM; endothelin ET(A) receptor antagonist; cyclo[DTrp-DAsp-Pro-DVal-Leu]) and abolished by either BQ-123 plus BQ-788 (1 microM; endothelin ET(B) receptor antagonist; N-cis-2,6-dimethylpiperidinocarbonyl-L-gamma-methylleucyl-D-1-methoxycarboyl-D-norleucine) or indomethacin. Thus, eicosanoids of the cyclo-oxygenase pathway (i.e. prostanoids) suppress endothelin-1-induced contractions of distal common bile duct and mediate endothelin ET(A) and ET(B) receptor-dependent inhibition of cholinergic responsiveness of the choledochal portion of the sphincter of Oddi.

Effect of cholephilic dyes on hepatic tight junctional permeability in the rat.

Changes in biliary permeability during cholephilic dye-induced choleresis, as assessed by measuring the movement into bile of two permeability probes, [14C]sucrose and horseradish peroxidase, were analyzed following an i.v. infusion (60 nmol/min per 100 g body wt) of the model cholephilic organic anion sulfobromophthalein in rats. Dye infusion led to a progressive increase of the [14C]sucrose bile-to-plasma ratio, which reached a maximum value after 100 min of dye infusion (+97%). Paracellular entry of horseradish peroxidase, as evaluated by the early peak of its biliary appearance curve, was also selectively increased (+69%), without changes in the later (transcytotic) access of the protein. Additional dose-response studies of biliary permeability to [14C]sucrose, using sulfobromophthalein and rose bengal, showed that this effect was dose-dependent and rapidly reversed by interruption of dye administration. The influence of hydrophobic/hydrophilic balance on this effect was also studied by infusing four dyes covering a broad range of hydrophobicity (phenol red, bromocresol green, sulfobromophthalein, and rose bengal), so as to attain a similar value of dye hepatic content at the end of the experiment (approximately 150 nmol/g liver wt). Under these conditions, a strong positive correlation was found between the increase in biliary permeability to [14C]sucrose and dye hydrophobicity. These results suggest that cholephilic dyes increase tight junctional permeability in a reversible and dose-dependent manner, and that this effect depends on the hydrophobic/hydrophilic balance of the dye.

Pressäo colecistociânica durante anestesia / Common bile duct pressure during anesthesia

Descreve-se um estudo experimental para verificar o comportamento das pressöes da via biliar de cäes após a administraçäo de drogas venosas. Foram estudados 45 cäes divididos em três grupos de 15 e identificados de acordo com a droga empregada por via venosa: nalbufina, fentanil e quetamina. A induçäo da anestesia em todos os grupos foi realizada com tiopental sódico por via venosa e o relaxamento muscular foi obtido com galamina. A ventilaçäo foi controlada manual, através de um AMBU, utilizando ar atmosférico. No grupo da nalbufina foi administrada dose única de 1 mg.kg-1. No grupo do fentanil, uma dose inicial de 10 micron g.kg-1 era injetada no tempo 0(zero); metade desta era repetida 15 minutos após. No grupo da quetamina era injetada uma dose inicial de 2 mg.kg-1 e repetida 15 minutos após. As pressöes da via biliar foram medidas através de um catéter colocado na vesícula dos animais. Após a administraçäo do fentanil houve um aumento significante (p < 0,05) na pressäo colecistociânica. Os valores médios se elevaram de 7,6 + ou - 3,9 cm H2O (basal) para 12,3 + ou - 7,1 cm H2O aos 25 minutos (pico). Quando a nalbufina foi usada a pressäo colecistociânica aumentou muito pouco; do valor basal médio de 7,6 + ou - 3,9 cm H2O elevou-se a um máximo de 9,1 + ou - 5,7 cm H2O aos 30 minutos. A quetamina praticamente näo elevou a pressäo colecistociânica. As variaçöes da pressäo arterial, embora tenham sido significantes com os três agentes, näo chegaram a níveis que pudessem produzir repercussäo clínica. Conclui-se que os morfinomimétricos em estudo determinam aumento da pressäo colecistociânica do cäo; tal alteraçäo é pronunciada com o uso de fentanil embora seja ignorado qual o comportamento da árvore biliar caso o estudo tivesse sido mais prolongado no grupo da nalbufina. A quetamina näo altera a pressäo da via biliar

[Effects of choledochal perfusion with biliary acid solutions on activity of the sphincter of Oddi (author's transl)]. / Efeitos da perfusão do colédoco com soluções de acidos biliares sobre a atividade do esfincter de Oddi.

The changes of sphincter of Oddi's resistance, induced by choledochal perfusion of conjugated (taurocolic) and non-conjugated (colic) biliary acid solutions, in anesthetized dogs, were studied. The perfusions were made at a constant flow and intracholedochal pressures were registered. The mean number of contractions per minute, the mean maximal pressures and the mean minimal pressures in each study periods were analysed. The choledochal perfusion with the biliary acids solutions induced a slight but significative increase in sphincteric resistance. After 15 minutes, the perfusion with colic acid solution induced maximal pressures significantly more elevated than the ones observed with taurocolic acid solution. The non-conjugated solution induced a pressure tracing significantly distinct from the tracing observed with the conjugated acid solution. No changes in resistance were observed with a 2% NaCl solution. This implies that the observed changes in resistance were not related to osmotic stimulation of the sphincter of Oddi.