Behavioral alterations and Fos protein immunoreactivity in brain regions of bile duct-ligated cirrhotic rats

Chondroitin Sulfate Protects the Liver in an Experimental Model of Extra-Hepatic Cholestasis Induced by Common Bile Duct Ligation

During liver fibrogenesis, there is an imbalance between regeneration and wound healing. The current treatment is the withdrawal of the causing agent; thus, investigation of new and effective treatments is important. Studies have highlighted the action of chondroitin sulfate (CS) in different cells; thus, our aim was to analyze its effect on an experimental model of bile duct ligation (BDL). Adult Wistar rats were subjected to BDL and treated with CS for 7, 14, 21, or 28 days intraperitoneally. We performed histomorphometric analyses on Picrosirius-stained liver sections. Cell death was analyzed according to caspase-3 and cathepsin B activity and using a TUNEL assay. Regeneration was evaluated using PCNA immunohistochemistry. BDL led to increased collagen content with corresponding decreased liver parenchyma. CS treatment reduced total collagen and increased parenchyma content after 21 and 28 days. The treatment also promoted changes in the hepatic collagen type III/I ratio. Furthermore, it was observed that CS treatment reduced caspase-3 activity and the percentage of TUNEL-positive cells after 14 days and cathepsin B activity only after 28 days. The regeneration increased after 14, 21, and 28 days of CS treatment. In conclusion, our study showed a promising hepatoprotective action of CS in fibrogenesis induced by BDL.

Lactulose decreases neuronal activation and attenuates motor behavioral deficits in hyperammonemic rats

Lactulose is a nonabsorbable disaccharide commonly used in clinical practice to treat hepatic encephalopathy. However, its effects on neuropsychiatric disorders and motor behavior have not been fully elucidated. Male Wistar rats were bile-duct ligated, and 3 weeks after surgery, treated with lactulose administrated by gavage (1.43 or 3.57 g/kg), once a day for seven days. Plasma levels of ammonia, aspartate aminotransferase, total bilirubin, and creatinine were quantified and histopathological analysis of the livers was performed. Locomotor activity measurements were performed in an open field. The expression of water channel aquaporin-4 was investigated and the analysis of Fos protein immunoreactivity was used to evaluate the pattern of neural activation in brain areas related to motor behavior. Bile-duct ligated rats showed hyperammonemia, loss of liver integrity and function, impaired locomotor activity, reduced aquaporin-4 protein expression, and neuronal hyperactivity. Lactulose treatment was able to reduce ammonia plasma levels, despite not having an effect on biochemical parameters of liver function, such as aspartate aminotransferase activity and total bilirubin levels, or on the cirrhotic hepatic architecture. Lactulose was also able to reduce the locomotor activity impairments and to mitigate or reverse most changes in neuronal activation. Lactulose had no effect on reduced aquaporin-4 protein expression. Our findings confirm the effectiveness of lactulose in reducing hyperammonemia and neuronal hyperactivity in brain areas related to motor behavior, reinforcing the importance of its clinical use in the treatment of the symptoms of cirrhosis-associated encephalopathy.

Effects of electroacupuncture on stress and anxiety-related responses in rats

The aim of this work was to investigate if eletroacupuncture at PC6 would modulate the stress-induced anxiety-like behavior and the level of activation of several brain areas. Rats were distributed in groups: control; submitted to immobilization; submitted to immobilization and eletroacupuncture at PC6 or at the tail. Immobilization increased grooming and decreased stretched attend postures and the time spent in the open arms of the ele-vated plus-maze. Eletroacupuncture at PC6 or tail canceled the effect of immobilization on grooming and attenuated the stretched attend posture. Immobilization increased Fos-immunoreactivity in the prefrontal cortex, medial and central amygdala, paraventricular and dorsomedial nuclei of the hypothalamus, lateral hypothalamus, dentate gyrus, CA1, CA2 and CA3 hippocampal areas. The activation of paraventricular, dorsomedial nuclei and prefrontal cortex by immobilization was canceled by electroacupuncture at PC6 and attenuated by electroacupuncture in the tail. The activation of the other areas was canceled by electroacupuncture in PC6 or the tail. It is concluded that immobilization induced anxiety-like behavior that was moderately attenuated by eletroacupuncture with difference between the stimulation in PC6 or the rat tail. Eletroacupuncture showed specificity concerning to the attenuation of the effects of immobilization in the CNS areas related to the stress response, anxiety and cardiovascular system.