Opiate receptors and β-endorphin levels in brain areas of dogs with portal-systemic encephalopathy

Clinical observation has indicated a supersensitivity to morphine in patients with hepatic encephalopathy. With the aim of clarifying the issue, radioreceptor binding studies of opiate receptors were performed in frontal cortex and hypothalamus of 6 dogs with mild portal-systemic encephalopathy induced by chronic treatment with dimethylnitrosamine followed by porto-caval shunt end-to-side. beta-Endorphin assays were performed in the same areas with radioimmunoassay. Opiate receptors labeled with [3H]naloxone in both areas showed a significant increase in the receptor densities (Bmax) without changes in the dissociation constant (KD). In parallel beta-endorphin levels showed a decline during the development of encephalopathy in both areas. The increased densities of opiate receptors in the mild stage of encephalopathy may explain the supersensitivity to morphine in patients with liver diseases.     

Relationships between squalene and cholesterol in bile: effect of ursodeoxycholic acid administration in patients with radiolucent gallstones

Squalene is an obligate intermediate of cholesterol synthesis and plasma squalene to cholesterol ratio correlates significantly with cholesterol synthesis rate in the liver. Sixteen nonobese patients with radiolucent gallstones were randomly allocated into two treatment groups receiving 15 mg/kg/day ursodeoxycholic acid (group A) or 15 mg/kg/day lactose (group B) administered three times daily for 30 days. In group A, biliary squalene to cholesterol ratio was significantly lowered (from 1.19 to 0.86, P less than 0.02), as was cholesterol saturation (from 1.39 to 0.95, P less than 0.001); levels of plasma very-low-density lipoprotein cholesterol (VLDL-C) (from 30 to 26 mg/dL) and plasma VLDL-triglyceride (VLDL-TG) (from 81 to 68 mg/dL) decreased significantly only in the group taking ursodeoxycholic acid. No variations of squalene concentrations and squalene to cholesterol ratio were observed in the plasma of both groups. Biliary cholesterol saturation during ursodeoxycholic acid administration correlated directly with squalene to cholesterol ratio in bile; reduction of these two parameters is accompanied by decreased VLDL-C levels.