Hepatic Osteodystrophy: The Mechanism of Bone Loss in Hepatocellular Disease and the Effects of Pamidronate Treatment

OBJECTIVES: The present study was designed to evaluate the bone phenotypes and mechanisms involved in bone disorders associated with hepatic osteodystrophy. Hepatocellular disease was induced by carbon tetrachloride (CCl4). In addition, the effects of disodium pamidronate on bone tissue were evaluated. METHODS: The study included 4 groups of 15 mice: a) C = mice subjected to vehicle injections; b) C+P = mice subjected to vehicle and pamidronate injections; c) CCl4+V = mice subjected to CCl4 and vehicle injections; and d) CCl4+P = mice subjected to CCl4 and pamidronate injections. CCl4 or vehicle was administered for 8 weeks, while pamidronate or vehicle was injected at the end of the fourth week. Bone histomorphometry and biomechanical analysis were performed in tibiae, while femora were used for micro-computed tomography and gene expression. RESULTS: CCl4 mice exhibited decreased bone volume/trabecular volume and trabecular numbers, as well as increased trabecular separation, as determined by bone histomorphometry and micro-computed tomography, but these changes were not detected in the group treated with pamidronate. CCl4 mice showed increased numbers of osteoclasts and resorption surface. High serum levels of receptor activator of nuclear factor-κB ligand and the increased expression of tartrate-resistant acid phosphatase in the bones of CCl4 mice supported the enhancement of bone resorption in these mice. CONCLUSION: Taken together, these results suggest that bone resorption is the main mechanism of bone loss in chronic hepatocellular disease in mice

Aflatoxin B1 residues in human livers and their relationship with markers of hepatic carcinogenesis in São Paulo, Brazil

In this study, hepatic biopsies from autopsy cases in São Paulo, Brazil, showing hepatocellular carcinoma (HCC, n = 8), cirrhosis associated with viral hepatitis (VC, n = 20), cirrhosis associated with alcoholism (AC, n = 20), and normal livers (NL or controls, n = 10) were subjected to determination of aflatoxin B1 (AFB1) and its main metabolites, and of markers of hepatic carcinogenesis Only non-metabolized AFB1 was detected in 13 samples (27.1%, N = 48) of liver disorders (HCC, VC and AC), at levels between 10.0 and 418.0 pg/g (mean: 76.6 ± 107.7 pg/g). Immuno-labeling of p53, cyclin D1, p21, β-catenin, and Prohibitin (PB) increased mainly in HCC patients, in relation to the controls. AFB1+ samples of HCC presented higher expressions of p53, cyclin D1, p21, and β-catenin compared with AFB1-livers. In contrast, p27, p16, and Rb immuno-labeling decreased in HCC, VC, and AC samples, compared with NL, with lowest values in AFB1+ samples for all liver disorders. Compared with NL, gene expression of cyclin D1 and PB in AFB1+ samples of HCC and AC were also higher, along with higher gene expression of p21 in VC and AC AFB1+ livers. Results indicated that patients with liver disorders were exposed to dietary aflatoxins, and that residual AFB1 in liver negatively affected the p53 and protein Rb pathways in HCC. Moreover, the presence of AFB1 in cirrhotic livers warrants concern about the potential contribution of dietary aflatoxin to disease progression during VC and AC. Keywords: AFB1, Hepatocellular carcinoma, Cirrhosis, Marker

Functional and structural changes in internal pudendal arteries underlie erectile dysfunction induced by androgen deprivation

Androgen deficiency is strongly associated with erectile dysfunction (ED). Inadequate penile arterial blood flow is one of the major causes of ED. The blood flow to the corpus cavernosum is mainly derived from the internal pudendal arteries (IPAs); however, no study has evaluated the effects of androgen deprivation on IPA's function. We hypothesized that castration impairs IPAs reactivity and structure, contributing to ED. In our study, Wistar male rats, 8-week-old, were castrated and studied 30 days after orchiectomy. Functional and structural properties of rat IPAs were determined using wire and pressure myograph systems, respectively. Protein expression was determined by Western blot and immunohistochemistry. Plasma testosterone levels were determined using the IMMULITE 1000 Immunoassay System. Castrated rats exhibited impaired erectile function, represented by decreased intracavernosal pressure/mean arterial pressure ratio. IPAs from castrated rats exhibited decreased phenylephrine- and electrical field stimulation (EFS)-induced contraction and decreased acetylcholine- and EFS-induced vasodilatation. IPAs from castrated rats exhibited decreased internal diameter, external diameter, thickness of the arterial wall, and cross-sectional area. Castration decreased nNOS and α-actin expression and increased collagen expression, p38 (Thr180/Tyr182) phosphorylation, as well as caspase 3 cleavage. In conclusion, androgen deficiency is associated with impairment of IPA reactivity and structure and increased apoptosis signaling markers. Our findings suggest that androgen deficiency-induced vascular dysfunction is an event involving hypotrophic vascular remodeling of IPAs

Bilioduodenal anastomosis in rats with extra-hepatic biliary obstruction is followed by lesions ischemia and reperfusion-induced Lesão de isquemia e reperfusão em ratos com obstrução biliar extra-hepática submetidos à anastomose bilio-duodenal

PURPOSE: The aim of this study was to investigate alterations compatible with hepatic ischemia-reperfusion after bilioduodenal shunt (BD) in rats with obstructive jaundice (OB) . METHODS: Thirty six animals were divided into 6 experimental groups: CO1 and CO2 - control groups, sham-operated (SO) and evaluated 6 and 24 hours after, respectively; OB1 and OB2, - obstructive jaundice groups, sham-operated 15 days after bile duct ligature and evaluated 6 and 24 hours after SO, respectively; DBD1and DBD2 - obstructive jaundice groups evaluated ,respectively, 6 and 24 hours after BD performed 15 days after bile duct ligature. The parameters evaluated were serum total bilirubin, aminotransferase activity (AST, ALT), TNFalpha, liver mitochondrial functions and parenchymatous injury. RESULTS: Bilirubin decreased while aminotransferase activity increased 6 hours after BD (p<0.01); TNFalpha determination at the 6th hour after BD was higher than the one at the 24th hour (p<0.05); oxygen consumption in states 3 and 4 remained elevated in the BD initial phase , and liver cell damage worsened 24 hours after BD. CONCLUSION: The results demonstrated that surgical biliary decompression in obstructive jaundice is followed by alterations related to hepatic ischemia- reperfusion.<br>OBJETIVO: O objetivo do estudo foi investigar alterações compatíveis com o fenômeno de isquemia-reperfusão hepática em ratos com icterícia obstrutiva (OB) após derivação bilioduodenal (BD). MÉTODOS: Trinta e seis animais foram divididos em seis grupos experimentais: CO1 e CO2 - grupos controle avaliados com 6 e 24 horas após operação simulada (SO), respectivamente; OB1 e OB2 - grupos com obstrução biliar, submetidos a SO 15 dias após ligadura do ducto biliar, e avaliados em 6 e 24 horas após a SO, respectivamente; DBD1 e DBD2 - grupos com 15 dias de obstrução biliar, avaliados em 6 e 24 horas, respectivamente, após BD. Os parâmetros avaliados foram bilirrubinas, aminotranferases (ALT e AST), funções mitocondriais hepáticas, dosagem de TNFalfa e lesão do parênquima hepático. RESULTADOS: As bilirrubinas caíram após BD, enquanto as aminotransferases aumentaram 6 horas após BD (p<0,01). O TNFalfa mensurado na 6ª hora após a BD foi maior que o da 24ª hora (p<0,05). O consumo de oxigênio no estado 3 e 4 mantiveram-se elevados na fase inicial do BD e as lesões celulares hepáticas agravaram-se na 24ª hora pós BD. CONCLUSÃO: Os resultados demonstraram que a descompressão cirúrgica biliar na icterícia obstrutiva foi seguida de alterações que correspondem ao fenômeno de isquemia-reperfusão hepática

Hepatic Osteodystrophy: The Mechanism of Bone Loss in Hepatocellular Disease and the Effects of Pamidronate Treatment

OBJECTIVES: The present study was designed to evaluate the bone phenotypes and mechanisms involved in bone disorders associated with hepatic osteodystrophy. Hepatocellular disease was induced by carbon tetrachloride (CCl4). In addition, the effects of disodium pamidronate on bone tissue were evaluated. METHODS: The study included 4 groups of 15 mice: a) C = mice subjected to vehicle injections; b) C+P = mice subjected to vehicle and pamidronate injections; c) CCl4+V = mice subjected to CCl4 and vehicle injections; and d) CCl4+P = mice subjected to CCl4 and pamidronate injections. CCl4 or vehicle was administered for 8 weeks, while pamidronate or vehicle was injected at the end of the fourth week. Bone histomorphometry and biomechanical analysis were performed in tibiae, while femora were used for micro-computed tomography and gene expression. RESULTS: CCl4 mice exhibited decreased bone volume/trabecular volume and trabecular numbers, as well as increased trabecular separation, as determined by bone histomorphometry and micro-computed tomography, but these changes were not detected in the group treated with pamidronate. CCl4 mice showed increased numbers of osteoclasts and resorption surface. High serum levels of receptor activator of nuclear factor-κB ligand and the increased expression of tartrate-resistant acid phosphatase in the bones of CCl4 mice supported the enhancement of bone resorption in these mice. CONCLUSION: Taken together, these results suggest that bone resorption is the main mechanism of bone loss in chronic hepatocellular disease in mice