Is liver transplantation associated with decreased bone mass in climacteric women?

PURPOSE: To evaluate whether climacteric women undergoing liver transplantation had higher prevalence of decreased bone mass than those without any liver disease. METHODS: A cross-sectional study with 48 women receiving follow-up care at a university hospital in Southeastern Brazil, from February 4th 2009 to January 5th 2011, was conducted. Of these women, 24 were 35 years or older and had undergone liver transplantation at least one year before study entry. The remaining 24 women had no liver disease and their ages and menstrual patterns were similar to those of transplanted patients. Laboratorial tests (follicle-stimulating hormone and estradiol) and bone density measurements of the lumbar spine and femur (equipment Hologic, Discovery WI) were performed. Statistical analysis was carried out by Fisher's exact test, simple Odds Ratio (OR), and multiple logistic regression. RESULTS: Mean age of the women included in the study was 52.8 (±10.7) years-old, 27.1% were premenopausal and 72.9% were peri/postmenopausal. Approximately 14.6% of these women exhibited osteoporosis and 35.4% had low bone mass. The following items were associated with decreased bone mass: being postmenopausal (OR=71.4; 95%CI 3.8 - 1,339.7; p<0.0001), current age over 49 years-old (OR=11.4; 95%CI 2.9 - 44.0; p=0.0002), and serum estradiol levels lower than 44.5 pg/mL (OR=18.3; 95%CI 3.4 - 97.0; p<0.0001). Having a history of liver transplantation was not associated with decreased bone mass (OR=1.4; 95%CI 0.4 - 4.3; p=0.56). CONCLUSION: Liver transplantation was not associated with decreased bone mass in this group of climacteric women.

Quality of life and menopausal symptoms in women with liver transplants

PURPOSE: To assess quality of life and climacteric symptoms in women with and without liver transplants. METHODS: This was a cross-sectional study of 52 women undergoing follow-up at a university hospital in southeastern Brazil from February 4th, 2009 to January 5th, 2011. Twenty-four of these women were 35 years old or older and had undergone liver transplantation at least one year before study entry. The remaining 28 women had no liver disease and were matched by age and menstrual patterns to the patients with transplants. The abbreviated version of the World Health Organization (WHOQOL-BREF) questionnaire was used to assess quality of life. Menopausal symptoms were assessed using the Menopause Rating Scale (MRS). Statistical analysis was carried out by Student's t-test, Mann-Whitney test and analysis of variance. Correlations between MRS and the WHOQOL-BREF were established by correlation coefficients. RESULTS: The mean age of the women included in the study was 52.2 (±10.4) years and the mean time since transplantation was 6.1 (±3.3) years. Women with liver transplants had better quality of life scores in the environment domain (p=0.01). No difference was noted between the two groups in any domain of the MRS. For women in the comparison group, there was a strongly negative correlation between somatic symptoms in the MRS and the physical domain of the WHOQOL-BREF (p<0.01; r=-0.8). In contrast, there was only a moderate association for women with liver transplants (p<0.01; r=-0.5). CONCLUSIONS: Women with liver transplants had better quality of life scores in the domain related to environment and did not exhibit more intense climacteric symptoms than did those with no liver disease. Climacteric symptoms negatively influenced quality of life in liver transplant recipients, although less intensely than in women without a history of liver disease.

Histopathological changes in liver and gill epithelium of Nile tilapia, Oreochromis niloticus, exposed to waterborne copper

Nile tilapia, Oreochromis niloticus, of both sexes were reared in freshwater and exposed to 0.5, 1.0 and 2.5mg L-1 of waterborne copper for a period of 21 days. Liver and gill samples were collected after 21 days of exposure to copper and lesions were analyzed by light microscopy. The main histopathological changes observed in gills exposed to the highest concentration were edema, lifting of lamellar epithelia and an intense vasodilatation of the lamellar vascular axis. Although less frequent, lamellar fusion caused by the filamentar epithelium proliferation and some lamellar aneurisms were also found. The liver of control group exhibited a quite normal architecture, while the fish exposed to copper showed vacuolation and necrosis. These hepatic alterations were more evident in fish exposed to 1.0 and 2.5mg L-1 copper concentrations. The number of hepatocytes nucleus per mm² of hepatic tissue decreased with the increase of copper concentration. In contrast, the hepatic somatic index was high in fish exposed at 2.5mg L-1 of copper. In short, this work advance new knowledge as influence of copper in the gill and liver histology of O. niloticus and demonstrated that their effects could be observed at different concentrations.

Expression and distribution of connexin 32 in rat liver with experimentally induced fibrosis

The connexin 32 (Cx32) is a protein that forms the channels that promote the gap junction intercellular communication (GJIC) in the liver, allowing the diffusion of small molecules through cytosol from cell-to-cell. Hepatic fibrosis is characterized by a disruption of normal tissue architeture by cellular lesions, and may alter the GJIC. This work aimed to study the expression and distribution of Cx32 in liver fibrosis induced by the oral administration of dimethylnitrosamine in female Wistar rats. The necropsy of the rats was carried out after five weeks of drug administration. They presented a hepatic fibrosis state. Sections from livers with fibrosis and from control livers were submitted to immunohistochemical, Real Time-PCR and Western-Blot analysis to Cx32. In fibrotic livers the Cxs were diffusely scattered in the cytoplasm, contrasting with the control livers, where the Cx32 formed junction plaques at the cell membrane. Also it was found a decrease in the gene expression of Cx32 without reduction in the protein quantity when compared with controls. These results suggest that there the mechanism of intercellular communication between hepatocytes was reduced by the fibrotic process, which may predispose to the occurrence of a neoplastic process, taken in account that connexins are considered tumor suppressing genes.

AT1-receptor mediated vascular damage in myocardium, kidneys and liver in rats

The systemic aspect of vascular damage induced by angiotensin II (ANG II) has been poorly explored in the literature. Considering the presence of ANG II and its specific receptor AT1, in several organs, all tissues might be potentially affected by its effects. The aims of this study were: To evaluate the early histological changes in the heart, liver and kidneys, produced by ANG II infusion, to evaluate the protective effect of losartan. Wistar rats were distributed into three groups: control (no treatment), treated with ANG II, and treated with ANG II + losartan. ANG II was continuously infused over 72 hours by subcutaneous osmotic pumps. Histological sections of the myocardium, kidneys and liver were stained and observed for the presence of necrosis. There were ANG II-induced perivascular inflammation and necrosis of the arteriolar wall in the myocardium, kidney, and liver by, which were partially prevented by losartan. There was no significant correlation between heart and kidney damage. Tissue lesion severity was lower than that of vascular lesions, without statistical difference between groups. ANG II causes vascular injury in the heart, kidneys and liver, indicating a systemic vasculotoxic effect; the mechanisms of damage/protection vary depending on the target organ; perivascular lesions may occur even when anti-hypertensive doses of losartan are used.

Sequencing and expression analysis of hepcidin mRNA in donkey (Equus asinus) liver

The hypoferremia that is observed during systemic inflammatory processes is mediated by hepcidin, which is a peptide that is mainly synthesized in the livers of several mammalian species. Hepcidin plays a key role in iron metabolism and in the innate immune system. It's up-regulation is particularly useful during acute inflammation, and it restricts the iron availability that is necessary for the growth of pathogenic microorganisms. In this study, the hepcidin mRNA of Equus asinus has been characterized, and the expression of donkey hepcidin in the liver has been determined. The donkey hepcidin sequence has an open reading frame (ORF) of 261 nucleotides, and the deduced corresponding protein sequence has 86 amino acids. The amino acid sequence of donkey hepcidin was most homologous to Equus caballus (98%). The mature donkey hepcidin sequence (25 amino acids) was 100% homologous to the equine mature hepcidin and has eight conserved cysteine residues that are found in all of the investigated hepcidin sequences. The expression profile of donkey hepcidin in the liver was high and was similar to the reference gene expression. The donkey hepcidin sequence was deposited in GenBankTM (HQ902884) and may be useful for additional studies on iron metabolism and the inflammatory process in this species.

Effects of the 2,4-D herbicide on gills epithelia and liver of the fish Poecilia vivipara

The 2,4-dichlorophenoxyacetic acid, usually named 2,4-D is one of the most widely used herbicides in the world. Acute toxicity of 2,4-D herbicide was investigated through its effects on guppies (Poecilia vivipara Bloch et Schneider 1801). Fish were exposed to the herbicide at concentrations of 10, 20 and 40µl per liter of water for 24 hours to determine its effects on gills and liver epithelia. The estimated LC50 was 34.64µl of 2,4-D per liter of water. Histochemical analyses and Feulgen's reaction were conducted to detect glycoconjugates and DNA, respectively, in gills and liver epithelia. Histochemistry revealed qualitative variations of glycoconjugates present on mucous cells and granules. The four types of mucous cells contained neutral granules, acids, or both. Increasing amounts of syalomucins were observed from the control group to the group exposed to the highest concentration of 2,4-D, suggesting increased mucous viscosity and the formation of plaques that could inhibit gas exchange and osmoregulation. Lamellar fusion observed in the group exposed to 40µl of 2,4-D suggests a defense mechanism. Hepatocytes showed vacuolization in the 10 and 20µl/L groups. The 40 µl/L group showed normal hepatocytes as well as changed ones, many Ito cells, micronuclei, and nuclear swelling. These effects may be associated with toxicity or adaptative processes to cellular stress. The data from this study indicates the importance of assessing similar risks to aquatic species and suggests that Poecilia vivipara is an adequate biological model for analysis of environmental contamination.

Celioscopic liver biopsy in silver catfish (Rhamdia quelen)

Endosurgery has been used for assessment of fish celomatic cavity, as well as for obtaining biopsies for organic analysis. Such minimally invasive access may also be used for the analysis of environmental impact on biomarkers of pollution. In Brazil, studies and literature regarding the use of celioscopy in fish are sparse. The purpose of the current study was to develop a two-port celioscopy technique to obtain liver biopsy in silver catfish (Rhamdia quelen). Six adult female silver catfish were used. The animals were anesthetized and the inspection of the celomatic cavity were performed using a telescope and celioscopic-guided liver biopsy were taken using laparoscopic Kelly forceps. On the early postoperative period, the animals were released in a confined water reservoir where mortality could be checked. The liver samples were sent for histological assessment. There were no complications during surgery on early postoperative period. It was possible to visualize meticulously several organs (liver, spleen, stomach, pancreas, swim bladder, ovaries, bowel and transverse septum). In conclusion, the surgical technique and the anesthetic protocol proposed were suitable to perform liver biopsies in silver catfish and provided low morbidity.

Effects of Cinnamon extract on biochemical enzymes, TNF-α and NF-κB gene expression levels in liver of broiler chickens inoculated with Escherichia coli

Abstract: Infection with Escherichia coli (E. coli) is a common disease in poultry industry. The use of antibiotics to treat diseases is facing serious criticism and concerns. The medicinal plants may be effective alternatives because of their multiplex activities. The aim of this study was to investigate the effects of cinnamon extract on the levels of liver enzymes, tumor necrosis factor-alpha (TNF-α) and nuclear factor-kappa B (NF-κB) gene expressions in liver of broiler chickens infected with E. coli. Ninety Ross-308 broilers were divided into healthy or E. coli-infected groups, receiving normal or cinnamon extract (in concentrations of 100 or 200mg/kg of food) supplemented diets. E. coli suspension (108cfu) was injected subcutaneously after 12 days cinnamon administration. Seventy-two hours after E. coli injection, the blood samples were taken for biochemical analysis of liver enzymes in serum (spectrophotometrically), and liver tissue samples were obtained for detection of gene expression of inflammatory markers TNF-α and NF-κB, using real-time PCR. Infection with E. coli significantly increased the levels of TNF-α and NF-κB gene expressions as well as some liver enzymes including creatine-kinase (CK), lactate-dehydrogenase (LDH), alanine-transferase (ALT) and aspartate-transferase (AST) as compared with control group (P<0.05). Pre-administration of cinnamon extract in broilers diet (in both concentrations) significantly reduced the tissue levels of TNF-α and NF-κB gene expressions and enzymes CK and ALT in serum of broiler chickens inoculated with E. coli in comparison with E. coli group (P<0.05 and P<0.01). The levels of LDH and AST were significantly decreased only by 200mg/kg cinnamon extract in infected broilers. The level of alkaline-phosphatase (ALP) was not affected in any groups. Pre-administration of cinnamon extract in diets of broiler chickens inoculated with E. coli could significantly reduce the gene expression levels of pro-inflammatory mediators and liver enzymes activities, thereby protecting the liver against this pathologic condition.

Apolipoprotein and lipid abnormalities in chronic liver failure

Total serum lipids, as well as apolipoproteins A-I (apo A-I) and B (apo B), were determined in 74 patients with chronic liver failure without cholestasis and in 82 normal subjects. The VLDL, LDL and HDL lipid fractions were reduced in the liver failure group by 36%, 24% and 46%, respectively (P<0.001). Apolipoproteins A-I and B were also reduced by 26% and 25%, respectively (P<0.001). However, the reduction of HDL cholesterol (HDLc) was more pronounced than that of apo A-I and the HDLc:apo A-I ratio was significantly lower in the liver failure group. After separating these patients into groups with plasma albumin lower than 3.0, between 3.0 and 3.5, and higher than 3.5 g/dl, the HDLc:apo A-I ratio was proportional to plasma albumin, but the correlation was not statistically significant. When these patients were separated by the Child classification of liver function, there was a correlation between the HDLc:apo A-I ratio and liver function. The differences in the HDLc:apo A-I ratio between the Child groups B and C, and A and C were statistically significant (P<0.05). We conclude that there is a more pronounced reduction in HDL cholesterol than in apo A-I in liver failure patients. Therefore, the HDLc:apo A-I ratio is a marker of liver function, probably because there is a decreased lecithin-cholesterol acyltransferase production by the diseased liver

Effects of estradiol benzoate on 5'-iodothyronine deiodinase activities in female rat anterior pituitary gland, liver and thyroid gland

There is little information on the possible effects of estrogen on the activity of 5'-deiodinase (5'-ID), an enzyme responsible for the generation of T3, the biologically active thyroid hormone. In the present study, anterior pituitary sonicates or hepatic and thyroid microsomes from ovariectomized (OVX) rats treated or not with estradiol benzoate (EB, 0.7 or 14 µg/100 g body weight, sc, for 10 days) were assayed for type I 5'-ID (5'-ID-I) and type II 5'-ID (5'-ID-II, only in pituitary) activities. The 5'-ID activity was evaluated by the release of 125I from deiodinated 125I rT3, using specific assay conditions for type I or type II. Serum TSH and free T3 and free T4 were measured by radioimmunoassay. OVX alone induced a reduction in pituitary 5'-ID-I (control = 723.7 ± 67.9 vs OVX = 413.9 ± 26.9; P<0.05), while the EB-treated OVX group showed activity similar to that of the normal group. Thyroid 5'-ID-I showed the same pattern of changes, but these changes were not statistically significant. Pituitary and hepatic 5'-ID-II did not show major alterations. The treatment with the higher EB dose (14 µg), contrary to the results obtained with the lower dose, had no effect on the reduced pituitary 5'-ID-I of OVX rats. However, it induced an important increment of 5'-ID-I in the thyroid gland (0.8 times higher than that of the normal group: control = 131.9 ± 23.7 vs ovx + EB 14 µg = 248.0 ± 31.2; P<0.05), which is associated with increased serum TSH (0.6-fold vs OVX, P<0.05) but normal serum free T3 and free T4. The data suggest that estrogen is a physiological stimulator of anterior pituitary 5'-ID-I and a potent stimulator of the thyroid enzyme when employed at high doses

The insulin receptor substrate 1 associates with phosphotyrosine phosphatase SHPTP2 in liver and muscle of rats

Insulin stimulates the tyrosine kinase activity of its receptor resulting in the phosphorylation of its cytosolic substrate, insulin receptor substrate-1 (IRS-1) which, in turn, associates with proteins containing SH2 domains. It has been shown that IRS-1 associates with the tyrosine phosphatase SHPTP2 in cell cultures. While the effect of the IRS-1/SHPTP2 association on insulin signal transduction is not completely known, this association may dephosphorylate IRS-1 and may play a critical role in the mitogenic actions of insulin. However, there is no physiological demonstration of this pathway of insulin action in animal tissues. In the present study we investigated the ability of insulin to induce association between IRS-1 and SHPTP2 in liver and muscle of intact rats, by co-immunoprecipitation with anti-IRS-1 antibody and anti-SHPTP2 antibody. In both tissues there was an increase in IRS-1 association with SHPTP2 after insulin stimulation. This association occurred when IRS-1 had the highest level of tyrosine phosphorylation and the decrease in this association was more rapid than the decrease in IRS-1 phosphorylation levels. The data provide evidence against the participation of SHPTP2 in IRS-1 dephosphorylation in rat tissues, and suggest that the insulin signal transduction pathway in rat tissues is related mainly to the mitogenic effects of the hormone.

Insulin receptor has tyrosine kinase activity toward Shc in rat liver

Insulin induces tyrosine phosphorylation of Shc in cell cultures and in insulin-sensitive tissues of the intact rat. However, the ability of insulin receptor (IR) tyrosine kinase to phosphorylate Shc has not been previously demonstrated. In the present study, we investigated insulin-induced IR tyrosine kinase activity towards Shc. Insulin receptor was immunoprecipitated from liver extracts, before and after a very low dose of insulin into the portal vein, and incubated with immunopurified Shc from liver of untreated rats. The kinase assay was performed in vitro in the presence of exogenous ATP and the phosphorylation level was quantified by immunoblotting with antiphosphotyrosine antibody. The results demonstrate that Shc interacted with insulin receptor after infusion of insulin, and, more important, there was insulin receptor kinase activity towards immunopurified Shc. The description of this pathway in animal tissue may have an important role in insulin receptor tyrosine kinase activity toward mitogenic transduction pathways.

A liver metalloendopeptidase which degrades the circulating hypotensive peptide hormones bradykinin and atrial natriuretic peptide

A new metalloendopeptidase was purified to apparent homogeneity from a homogenate of normal human liver using successive steps of chromatography on DEAE-cellulose, hydroxyapatite and Sephacryl S-200. The purified enzyme hydrolyzed the Pro7-Phe8 bond of bradykinin and the Ser25-Tyr26 bond of atrial natriuretic peptide. No cleavage was produced in other peptide hormones such as vasopressin, oxytocin or Met- and Leu-enkephalin. This enzyme activity was inhibited by 1 mM divalent cation chelators such as EDTA, EGTA and o-phenanthroline and was insensitive to 1 µM phosphoramidon and captopril, specific inhibitors of neutral endopeptidase (EC 3.4.24.11) and angiotensin-converting enzyme (EC 3.4.15.1), respectively. With Mr 85 kDa, the enzyme exhibits optimal activity at pH 7.5. The high affinity of this endopeptidase for bradykinin (Km = 10 µM) and for atrial natriuretic peptide (Km = 5 µM) suggests that it may play a physiological role in the inactivation of these circulating hypotensive peptide hormones.

Effects of aluminum sulfate on delta-aminolevulinate dehydratase from kidney, brain, and liver of adult mice

The purpose of the present study was to investigate the in vitro and in vivo effects of aluminum sulfate on delta-aminolevulinic acid dehydratase (ALA-D) activity from the brain, liver and kidney of adult mice (Swiss albine). In vitro experiments showed that the aluminum sulfate concentration needed to inhibit the enzyme activity was 1.0-5.0 mM (N = 3) in brain, 4.0-5.0 mM (N = 3) in liver and 0.0-5.0 mM (N = 3) in kidney. The in vivo experiments were performed on three groups for one month: 1) control animals (N = 8); 2) animals treated with 1 g% (34 mM) sodium citrate (N = 8) and 3) animals treated with 1 g% (34 mM) sodium citrate plus 3.3 g% (49.5 mM) aluminum sulfate (N = 8). Exposure to aluminum sulfate in drinking water inhibited ALA-D activity in kidney (23.3 ± 3.7%, mean ± SEM, P<0.05 compared to control), but enhanced it in liver (31.2 ± 15.0%, mean ± SEM, P<0.05). The concentrations of aluminum in the brain, liver and kidney of adult mice were determined by graphite furnace atomic absorption spectrometry. The aluminum concentrations increased significantly in the liver (527 ± 3.9%, mean ± SEM, P<0.05) and kidney (283 ± 1.7%, mean ± SEM, P<0.05) but did not change in the brain of aluminum-exposed mice. One of the most important and striking observations was the increase in hepatic aluminum concentration in the mice treated only with 1 g% sodium citrate (34 mM) (217 ± 1.5%, mean ± SEM, P<0.05 compared to control). These results show that aluminum interferes with delta-aminolevulinate dehydratase activity in vitro and in vivo. The accumulation of this element was in the order: liver > kidney > brain. Furthermore, aluminum had only inhibitory properties in vitro, while in vivo it inhibited or stimulated the enzyme depending on the organ studied.