Anti-Inflammatory and Gut Microbiota Modulating Effects of Probiotic Lactobacillus paracasei MSMC39-1 on Dextran Sulfate Sodium-Induced Colitis in Rats.

Probiotics have been shown to possess several properties, depending on the strain. Some probiotics have important roles in preventing infection and balancing the immune system due to the interaction between the intestinal mucosa and cells in the immune system. This study aimed to examine the properties of three probiotic strains using the tumor necrosis factor-alpha (TNF-α) inhibition test in colorectal adenocarcinoma cells (Caco-2 cells). It was revealed that the viable cells and heat-killed cells of the probiotic L. paracasei strain MSMC39-1 dramatically suppressed TNF-α secretion in Caco-2 cells. The strongest strains were then chosen to treat rats with colitis induced by dextran sulfate sodium (DSS). Viable cells of the probiotic L. paracasei strain MSMC39-1 reduced aspartate transaminase and alanine transaminase in the serum and significantly inhibited TNF-α secretion in the colon and liver tissues. Treatment with the probiotic L. paracasei strain MSMC39-1 alleviated the colon and liver histopathology in DSS-induced colitis rats. Furthermore, supplementation with probiotic L. paracasei strain MSMC39-1 increased the genus Lactobacillus and boosted the other beneficial bacteria in the gut. Thus, the probiotic L. paracasei strain MSMC39-1 exhibited an anti-inflammation effect in the colon and modulated the gut microbiota.

Molecular Changes Following Induction of Hepatocellular Carcinoma by Diethylnitrosamine and Thioacetamide, and Subsequent Treatment with Dioscorea membranacea Extract.

Hepatocellular carcinoma (HCC) is a primary liver cancer commonly found in adults. Previously, we showed the anticancer effects of Thai herbal plant extract, Dioscorea membranacea Pierre (DM), in HCC-bearing rats. In the present study, we further examined the proposed mechanism of DM, including apoptosis and antioxidant activity. Moreover, we used RNA sequencing (RNA-seq) to analyze molecular pathways in the rat model in which HCC was induced by diethylnitrosamine (DEN) and thioacetamide (TAA). The HCC-bearing rats were then treated with 40 mg/kg of DM for 8 weeks, after which experimental and control rats were sacrificed and liver tissues were collected. The RNA-seq data of DEN/TAA-treated rats exhibited upregulation of 16 hallmark pathways, including epithelial mesenchymal transition, inflammatory responses, and angiogenesis (p<0.01). DM extract expanded the Bax protein-positive pericentral zone in the tumor areas and decreased hepatic malondialdehyde levels, implying a decrease in lipid peroxidation in liver. However, DM treatment did not ameliorate the molecular pathways induced in DEN/TAA-treated livers. Our findings indicate that DM extract has antioxidant activity and exerts its pro-apoptotic effect on rat HCCs in vivo at the (post-)translational level.

Therapeutic efficacy of a Dioscorea membranacea extract in a rat model of hepatocellular carcinoma: Histopathological aspects.

Hepatocellular carcinoma (HCC) is most common in adults and has a high mortality rate because of a lack of effective treatment options. We investigated the effect of a medicinal plant as a potential source of drugs against HCC. The rhizomes of Dioscorea membranacea Pierre (DM), Hua-Khao-Yen in Thai, are commonly used as ingredients for alternative treatment of cancer in Thailand. In this study, the anticancer effects of DM extract in HCC-bearing rats were evaluated with respect to gross morphology, histopathology, and leakage of liver enzymes. In untreated HCCs, typical features of liver cancer, including hepatic nodules, thick-cell cords, and pseudoglandular cell arrangements, were observed. In addition, the HCCs showed abnormal reticulin patterns and a high glypican3 expression. In HCC-bearing rats treated with DM the cancer areas and reticulin expression were significantly reduced compared to the untreated group (p < 0.01). Sorafenib, the standard drug to treat HCC, reduced the cancer area further, but increased leakage of liver enzymes and decreased serum albumin concentration, indicating liver toxicity. These findings suggest that DM has an anticancer effect on HCCs in an animal model in vivo with potentially less severe side effects than sorafenib. Therefore, further studies of DM's mechanism of action in HCC should be carried out.

α-mangostin preserves hepatic microvascular architecture in fibrotic rats as shown by scanning electron microscopy of vascular corrosion casts.

Liver fibrosis is a dynamic condition caused by wound-healing in which scar tissue replaces the liver parenchyma following repetitive injuries. It is hypothesized that α-mangostin (AM), the major constituent of the xanthone fraction in extracts of Garcinia mangostana L., may protect the hepatic microvascular bed from thioacetamide (TAA)-induced fibrosis. In the present study, rats were divided into 4 groups: Control rats received no treatment; TAA-treated rats received 150 mg/kg TAA 3 times per week intraperitoneally; AM-treated rats received 75 mg/kg AM twice per week intraperitoneally; and TAA+AM-treated rats received both TAA and AM as described above. Rat livers were processed either for light microscopy or for vascular corrosion casting after 30 and 60 days of treatment. Vascular parameters were measured by 3D morphometry analysis of scanning electron micrographs. AM attenuated hepatocellular injuries and delayed both periportal and pericentral fibrosis in the TAA-treated rats. The comparison of findings at day 30 and 60 showed that TAA-induced fibrotic changes were progressive in time, and that the beneficial effects of AM only became apparent after prolonged treatment. The livers of rats treated with both TAA and AM had less space surrounding the portal vessels, improved preservation of the hepatic microvascular pattern, and minimally altered sinusoidal patterns with few signs of terminal portal venule remodeling. AM therefore partially protected the liver against hepatotoxin-induced fibrosis and the associated microvascular changes. The mechanism of the protective effect of AM on the liver remains to be investigated.

Hepatoprotective Effect of Probiotic Lactic Acid Bacteria on Thioacetamide-Induced Liver Fibrosis in Rats.

Hepatic fibrosis is a reversible wound-healing response characterized by the accumulation of extracellular matrix. Probiotics have been used to prevent and treat various disorders. The aim of the present study was to investigate the hepatoprotective effects of probiotic lactic acid bacteria (mixture of Lactobacillus paracasei, Lactobacillus casei, and Weissella confusa) on thioacetamide (TAA)-induced liver fibrosis in rats. Thirty-five male Wistar rats were randomly divided into five groups: (1) control, (2) TAA, (3) TAA+probiotics, (4) TAA+silymarin, and (5) probiotics. Group 1 rats received a standard diet. In groups 2-4, fibrosis was induced by intraperitoneal injection of TAA (200 mg/kg BW) 3 times weekly for 8 consecutive weeks. Group 4 received TAA plus 100 mg/kg BW of silymarin 2 times weekly. Groups 3 and 5 were fed 109 CFU/mL viable microbial cells daily by gavage. The rats were sacrificed after 8 weeks of treatment. Liver tissues were collected immediately and processed for histopathological, lipid peroxidation, and Western blot analyses of TNF-α, TGF-ß1, and α-SMA. Blood serum was collected to measure liver enzymes. Rats in the TAA groups suffered from hepatic injury (increased serum enzyme levels, liver inflammation, and increased concentration of TNF-α, TGF-ß1, and α-SMA proteins) and extensive liver fibrosis. In contrast, TAA-treated rats receiving probiotics or silymarin had significantly lower serum enzyme levels, less inflammation, and less fibrosis. Liver damage was lower in the TAA+probiotics-treated group. Consumption of a mixture of probiotic lactic acid bacteria attenuates the development of liver fibrosis.

Anti-angiogenic and anti-proliferative effects of Benja-ummarit extract in rats with hepatocellular carcinoma.

The herbal extract Benja-ummarit (BU) is a traditional Thai medicine with a putative cancer-suppressing effect. However, this effect has only been tested in vitro in human hepatocarcinoma cell lines. The present study determined the efficacy of a BU extract to treat hepatocellular carcinoma (HCC) in rats in vivo and established its anti-angiogenic and anti-proliferative properties. The BU extract was prepared in 95% ethanol and its composition determined using liquid chromatography-mass spectrometry. HCC was induced in Wistar rats by an injection of diethylnitrosamine (DEN), followed 2 weeks later by injections of thioacetamide (TAA) thrice weekly for 4 weeks. Following 2 months, the DEN-TAA-treated rats were divided into 6 groups that were treated orally for another 2 months with: i) No treatment; ii) vehicle; iii) 30 mg/kg sorafenib (SF); iv) 1 mg/kg BU; v) 10 mg/kg BU; or vi) 50 mg/kg BU. Liver samples were collected for gross morphological, histological, reverse transcription-quantitative PCR and western blot analyses, and serum samples were collected for liver function tests. The size and number of the cancer nodules were reduced ~10-fold in BU-treated HCC groups and ~14-fold in the SF-treated group compared with the HCC group. Furthermore, the serum parameters of liver damage were lower in BU-compared with SF-treated rats. These results indicate that while each of these formulations strongly reduce HCC expansion, BU extract results in less liver damage. Vascular endothelial growth factor expression was reduced significantly in the BU-and SF-treated HCC groups compared with the HCC group (P<0.05). BU extract antagonizes HCC growth in vivo potently through inhibiting tumor angiogenesis. BU, therefore, qualifies as a promising medical herb requiring further evaluation as a treatment of HCC.

Protective effect of alpha-mangostin on thioacetamide-induced liver fibrosis in rats as revealed by morpho-functional analysis.

Liver fibrosis is an excessive accumulation of scar tissue resulting from inflammation and cell death. Thioacetamide (TAA) is a well-known hepatotoxin that induces liver fibrosis. A marker of injured hepatocytes is transforming growth factor-beta 1 (TGF-ß1), while alpha-smooth muscle actin (α-SMA) and tissue inhibitor of metalloproteinase 1 (TIMP-1) are markers of activated hepatic stellate cells. Alpha-mangostin, a major xanthone derivative from the mangosteen pericarp, has been shown to have anti-oxidant and anti-inflammatory activities. The objective of this study was to determine whether alpha-mangostin has a protective effect on TAA-induced liver fibrosis in rats. The rats were treated by intraperitoneal injection of compounds for eight weeks. For the control group a mixture of dimethyl sulfoxide and phosphate buffered saline was administered. Two hundred mg/kg BW of TAA was administered three times weekly. Alpha-mangostin was administered at 5 mg/kg BW and silymarin at 100 mg/kg BW, both twice weekly. TAA induced histologically recognizable liver damage and fibrosis, as anticipated. Furthermore, it increased immunohistochemically detectable TGF-ß1, α-SMA and TIMP-1. Co-administration of alpha-mangostin or silymarin with TAA prevented or ameliorated the effects of TAA administration alone. The anti-fibrotic effect of alpha-mangostin was stronger than that of silymarin.

Alpha-Mangostin Partially Preserves Expression of Ammonia-Metabolizing Enzymes in Thioacetamide-Induced Fibrotic and Cirrhotic Rats.

BACKGROUND: Ammonia metabolizing enzymes, carbamyol phosphate synthetase (CPS) and glutamine synthetase (GS), are expressed in the periportal and pericentral hepatocytes, respectively. CPS and GS function complementary to ensure complete ammonia detoxification. Immunohistochemical analysis confirmed the decline of both CPS and GS in cirrhotic rat liver induced by thioacetamide (TAA). Alpha-mangostin (AM), a major derivative of xanthone from mangosteen, has been reported to possess a wide range of pharmacological properties. OBJECTIVE: To examine the preventive effects of AM on CPS and GS expression in fibrotic and cirrhotic rats induced by TAA over sixteen weeks. MATERIAL AND METHOD: Twenty-four male Wistar rats were divided into 4 groups of 6 animals each. Group 1 was for control. Group 2 wasfor pure TAA treatment. Group 3 was for pure AM administration. Group 4, prevention group, was concurrently treated with TAA and AM. Immunohistochemical technique was employed in order to elucidate the expression of CPS and GS in each animal group. RESULTS: Immunohistochemical staining for CPS and GS showed an increasing decline from week eight to sixteen under pure-TAA condition. Fibrous bridgings, nodule formations, and regenerative nodules were detected. Pure-AM condition yielded strongly CPS and GS-stained hepatocytes in afashion similar to the control. Results from the prevention group showed a decreasing decline of CPS and GS immuno-reactivity from week eight to sixteen as compared to pure-TAA condition. Fewer fibrous portal-caval bridgings were observed at week eight and CPS-positive hepatocytes were found in continuous rings. CONCLUSION: Alpha-mangostin could partially preserve the normal expression of ammonia-metabolizing enzymes under TAA-induced fibrotic and cirrhotic conditions.

Collagen arrangement in space of Disse correlates with fluid flow in normal and cirrhotic rat livers.

Little is known about collagen arrangement in the space of Disse was related to the fluid flow both in normal and cirrhotic liver. We examined the changes in the arrangement of type-I collagen in thioacetamide-induced cirrhotic rat livers with immunohistochemistry and SEM after maceration of the noncollagenous tissues with NaOH. The sparse bundles of collagen fibers in the spaces of Disse were mostly elongated fibers with a disorganized arrangement in each nodule. They connected with the broad fibrous septa. Based on a comparison of the architecture of the collagen fibers and the established flow of fluid in the space of Disse, we hypothesize that the fluid in the space of Disse streams along collagen fibers in all directions to broad fibrous septa. The appearance of perinodular plexus in cirrhotic rat livers probably helps to reduce portal hypertension.

Rat ß3-adrenoceptor protein expression: antibody validation and distribution in rat gastrointestinal and urogenital tissues.

ß3-Adrenoceptors play important roles in the regulation of urogenital and probably gastrointestinal function. However, despite recent progress, their detection at the protein level has remained difficult due to a lack of sufficiently validated selective antibodies. Therefore, we have explored the selectivity of two antibodies for the detection of rodent ß3-adrenoceptors in immunoblots and immunohistochemistry. Of two reportedly promising candidates, antibody AB15688 did not exhibit subtype selectivity in immunoblots. In contrast, the antibody Sc1473 exhibited at least some selectivity in immunoblots and more promising results in immunocytochemical and immunohistochemical stains in cells transfected with cloned ß-adrenoceptor subtypes and in rat and mouse tissues. In a systematic screening of rat gastrointestinal and urogenital tissues, Sc1473 produced selective staining in the epithelial cell lining of the stomach and the urothelium of ureter and bladder. We conclude that the two tested antibodies are inappropriate or at least insufficient for immunoblotting applications, but Sc1473 appears to be useful for immunohistochemical detection of ß3-adrenoceptor protein in rodent tissues. The ß3-adrenoceptor protein exhibits a distinct expression pattern in the rat gastrointestinal and urogenital tract, which is at least partly in line with previously reported functional data.

Expressional changes of carbamoyl phosphate synthetase and glutamine synthetase in the liver of rat with thioacetamide-induced cirrhosis.

BACKGROUND: In order to detoxify ammonia, mammalian livers use carbamoyl phosphate synthetase (CPS) and glutamine synthetase (GS) for conversion into respective non-toxic urea and glutamine. CPS is expressed in the periportal hepatocytes whereas GS is contained in the pericentral hepatocytes. OBJECTIVE: To examine the expressional changes of CPS and GS in the liver being induced to become cirrhotic by hepatotoxin thioacetamide (TAA). MATERIAL AND METHOD: Twenty-five male Wistar rats were divided into 5 groups of 5 animals each. Group 1 was for control. Groups 2 to 5 were treated with 200 mg/kg TAA intraperitoneally three times weekly for 1, 2, 3 and 4 months respectively. The immunohistochemical technique was employed in order to elucidate the expression of CPS and GS in each animal group. RESULTS: As centro-central fibrous bridging developed in the course of TAA treatment, expression of CPS declined dramatically and that of GS was no longer restricted to the pericentral hepatocytes. In month 4, CPS-positive hepatocytes were only found in some regenerative nodules, whereas GS expression became confined to the nodular periphery. Proper CPS staining required tissue fixation in a mixture of methanol, acetone and water (2:2:1 v/v) as opposed to 4% paraformaldehyde. CONCLUSION: In response to the hepatotoxin TAA, the liver attempts to regenerate by means of conserving persistent CPS-positive hepatocytes and rearranging GS-positive hepatocytes in response to vascular obstruction.

Protective effect of alpha-mangostin against type-I collagen formation in thioacetamide-induced cirrhotic rat.

OBJECTIVE: To elucidate the protective effect of alpha-mangostin (alpha-MG) against increment of type-I collagen-positive hepatocytes in rat cirrhosis induced by thioacetamide (TAA). MATERIAL AND METHOD: Rats were separated into 4 groups. The first group was, the control, untreated with TAA. The cirrhotic rats, the second group, were induced by TAA injection (200 mg/kg), 3 times per week. Rats in the third group received treatment of TAA (200 mg/kg) alternating with alpha-MG (100 mg/kg) for every other day. Animals in the last group were treated only with alpha-MG (100 mg/kg), 3 times per week. The chemicals used each group were given intraperitoneally for 16 weeks. The type-I collagen and type-I collagen-positive hepatocytes were explored by using immunohistochemical technique. RESULTS: In cirrhotic livers type-I collagen was immunopositive in the connective tissue and a large number of hepatocytes. The number of type I collagen-positive-hepatocytes (414.00 +/- 25.23) in TAA-induced cirrhosis group increased significantly when compared to those in the control group (131.40 + 9.63). Interestingly, a significant decrease in the number of type-I collagen-positive-hepatocytes was observed in TAA-alpha-MG-prevention group (103.60 +/- 36.55) and in alpha-MG-injected group (54.00 +/- 5.30) compared to those in the control group and TAA-induced cirrhosis. CONCLUSION: 100 mg/kg of alpha-MG could lower the number of type-I collagen-positive-hepatocytes in TAA-induced cirrhosis. It is probable that alpha-MG helps to keep up more blood circulation to the liver cells through dilated sinusoids. This vascular adaptation enhances high oxygen blood to the hepatocytes which, in turn, reduces the damage of hepatocytes caused by TAA-derived reactive oxygen species.

Predominant vascular dilatation with NOS expression in lung lower lobe of thioacetamide induced-cirrhotic rat.

BACKGROUND: About eighteen percent of cirrhotic patients come along with decreased systemic arterial oxygenation and expansion of pulmonary venous plexus which triggered by nitric oxide. The level of nitrate and iNOS significantly increase in the cirrhotic patients. However the localization of nNOS and iNOS in the lung tissue has not yet been clarified. OBJECTIVE: The present study, therefore, aimed to demonstrate the sites of expansion of pulmonary blood vessels and to localize nNOS and iNOS in the lung tissue of cirrhotic rat models induced by thioacetamide (TAA). MATERIAL AND METHOD: The rats were divided into 5 groups. The first group was the control. The other four groups were treated with 200 mg/kg body weight of TAA 3 times per week for 1, 2, 3, or 4 month(s), respectively. At the end of each month rats in each treated group were sacrificed. Lung histology and pulmonary NOS expression was studied by light microscope and immunohistochemical technique, respectively. RESULTS: It was found that diameter of blood vessels were highest increased in the right lower lobe of the 4-months TAA-treated group. In addition, iNOS and nNOS expression was localized at epithelium of respiratory tract, endothelium of pulmonary vessel and macrophage at this age. CONCLUSION: The present study demonstrated that the pulmonary blood vessels at the right lower lobe with cirrhotic background got enormous dilatation. iNOS and nNOS were immunostained at epithelium of respiratory tract, pulmonary endothelium and macrophages. Our observations suggested that enhanced NOS expression is important in the development of systemic hyperdynamic circulatory abnormalities in cirrhosis. As appearance of vasodilatation at right lower lobe of lung, it could, therefore, be evidence confirming that there was a real connection between inferior pulmonary vein and azygos vein at the embryonic period but obliterated later.

Chronological production of thioacetamide-induced cirrhosis in the rat with no mortality.

BACKGROUND: Cirrhotic animal models are useful in studying complications of chronic liver disease. The authors chronologically investigated the effect of thioacetamide (TAA), administered intraperitoneally and adapted individually to weight changes, focusing on the optimal moment to obtain typical features of cirrhosis. MATERIAL AND METHOD: Male Wistar Rats,150-200 g, were intoxicated three times per week with TAA of 200 mg/kg for 4, 8, 12 or 16 weeks (n = 8 per group), respectively and compared with age-matched controls (n = 4 per group). The individual body weight and liver function test were also measured in each group. Liver samples from each group were histologically stained with Sirius red in order to identify the degree of liver fibrosis. RESULTS: Rats intoxicated for 4, 8, 12 or 16 weeks had no mortality and histologically showed hepatitis and advanced fibrosis. At 12 and 16 weeks, all animals showed macronodular cirrhosis with signs of high-grade hepatocellular dysplasia. The weight of the treated groups at different time points was significantly lower than the controls. Routine liver function tests between cirrhotic and control rats showed significantly higher only in alanine transaminase (ALT) and aspartate aminotransferase (AST) at 8 and 12 weeks. However in the cirrhotic rats at 16 weeks, the ALT and AST were much lower than that at 8 and 12 weeks but did not show any difference from the controls. CONCLUSION: Thioacetamide, adapted to individual weight changes, leads to a model of cirrhosis in the rat at 12 and 16 weeks with zero mortality.

Activated Ito cells of cirrhotic liver express M3 muscarinic receptor after thioacetamide exposure.

Ito cells or perisinusoidal stellate cells or hepatic fat storing cells are pericytes of normal liver sinusoidal endothelial cells. Activation of Ito cells by chemicals or toxins causes transdifferentiation into the main collagen-producing cells involving in the progression of liver cirrhosis. Quantitative analysis of Ito cell activation by immunohistochemistry has been shown to be useful in predicting the rate of progression of liver fibrosis in some clinical situations. The present study demonstrated that the activated Ito cells in thioacetamide-induced cirrhotic liver which were immunopositive with alpha smooth muscle actin, expressed M3 muscarinic receptor but not M1, M2, M4 and M5. These findings suggest that the M3 muscarinic receptor might involve in triggering intracellular signalling pathways in activated Ito cell to produce collagen fibers and may be of future interest in hepatic fibrosis therapy.

Distribution of Hepatic Myofibroblasts and Type I and III Collagen in Rat Liver Cirrhosis Induced by Thioacetamide / Distribución de Miofibroblastos y Colágeno Tipo I y III en Hígado de Ratas con Cirrosis Inducida por Tioacetamida

Thioacetamide (TAA) can induce various types of cirrhosis in the rat, including bridging fibrosis, biliary fibrosis, perisinusoidal/pericellular fibrosis and centrilobular fibrosis, in which different populations of hepatic myofibroblasts (MFs) are involved. The hepatic MFs can be classified into 3 groups: (a) portal/septal MFs; (b) activated hepatic stellate cell myofibroblasts (HSC/MFs); and (c) interface myofibroblasts (IF/MFs). The present study was carried out to examine the morphology and localization of hepatic MFs in relation to the distribution of type I and III collagen in rat cirrhotic livers. Immunohistochemistry to a-smooth muscle actin was employed to demonstrate the morphology and localization of the subpopulations of hepatic MFs. The distribution of type I and III collagen was investigated by using specific antibodies. Portal and septal MFs were windmill in shape and localized around tributaries of the portal and hepatic veins where type I and III collagen was accumulated. HSC/MFs with arachnoid in shape were localized in the spaces of Disse and spaces between neighboring hepatocytes where type I collagen was formed. IF/MFs showed arachnoid shapes and distributed along the margin of fibrous septa where type I collagen was condensed. MFs with polygonal shapes were also found around the wall of hepatic sinusoids, margin of fibrous septa and around the portal tract. They were probably transitional cells to the mature MFs. Our data suggest that each subpopulation of hepatic MFs shows characteristic morphology and localization, which correlates with localization of type I and/or type III collagen.

La tioacetamida (TAA) puede provocar diversos tipos de cirrosis hepática en la rata, incluyendo fibrosis en puente, fibrosis biliar, fibrosis perisinusoidal/pericelular y fibrosis centrolobulillar, en los que diferentes poblaciones de miofibroblastos hepáticos (MFs) están involucrados. Los MFs hepáticos se pueden clasificar en tres grupos: (a) MFs portal/ septal; (b) células estrelladas hepática activada miofibroblásticas (HSC/MFs), y (c) miofibroblastos de interface (IF/MFs). El presente estudio se realizó para examinar la morfología y localización de los MFs hepáticos en relación con la distribución de colágeno Tipos I y III en el hígado de ratas cirróticas. Se utilizó inmunohistoquímica de a-actina de músculo liso para demostrar la morfología y localización de las subpoblaciones de MFs hepática. La distribución de colágenos Tipos I y III se investigó utilizando anticuerpos específicos. FMs portales y septales mostraron forma de molino de viento y se localizaron cerca de afluentes de las venas porta y hepática donde los colágenos Tipos I y III se acumularon. HSC/MFs con forma aracnoide se localizaron en los espacios de Disse y los espacios entre hepatocitos vecinos, donde se formó el colágeno Tipo I. IF/MFs mostraron formas aracnoides y se distribuyeron a lo largo del margen de los septos fibrosos donde se condensó el colágeno Tipo I . MFs con formas poligonales también fueron encontrados alrededor de la pared de los sinusoides hepáticos, en el margen de los septos fibrosos y en todo el tracto portal. Probablemente fueron células de transición a los MFs maduros. Nuestros datos sugieren que cada subpoblación de MFs hepáticos muestra una morfología y localización característica, que se correlaciona con la localización de colágenos Tipo I y o III.

Anatomy and histology of the lower urinary tract.

The function of the lower urinary tract is basically storage of urine in the bladder and the at-will periodic evacuation of the stored urine. Urinary incontinence is one of the most common lower urinary tract disorders in adults, but especially in the elderly female. The urethra, its sphincters, and the pelvic floor are key structures in the achievement of continence, but their basic anatomy is little known and, to some extent, still incompletely understood. Because questions with respect to continence arise from human morbidity, but are often investigated in rodent animal models, we present findings in human and rodent anatomy and histology. Differences between males and females in the role that the pelvic floor plays in the maintenance of continence are described. Furthermore, we briefly describe the embryologic origin of ureters, bladder, and urethra, because the developmental origin of structures such as the vesicoureteral junction, the bladder trigone, and the penile urethra are often invoked to explain (clinical) observations. As the human pelvic floor has acquired features in evolution that are typical for a species with bipedal movement, we also compare the pelvic floor of humans with that of rodents to better understand the rodent (or any other quadruped, for that matter) as an experimental model species. The general conclusion is that the "Bauplan" is well conserved, even though its common features are sometimes difficult to discern.

From prenatal life into senescence, testosterone is essential requirement for manhood.

Prenatally, organisms have the bipotentiality to differentiate along either male or female lines, a process with different stages, each with a narrow window of time, during which testosterone plays a pivotal role in the case of male sexual differentiation. During puberty, the body directs the masculinization process with growth of the genitalia and prostate. Body contours become male, with an average height of 10-15 centimeters greater than that of females, a greater bone and muscle mass, a male hair pattern and a male-type fat distribution. These pubertal developments, largely reversible in case of severe androgen deficiency, require adult levels of testosterone throughout life. A new area of interest is in exploring how far age-related body changes (loss of bone and muscle mass, a shift into a higher ratio of body fat/lean body mass) are part of an age-related decline of testicular testosterone production. Therefore, throughout life, testosterone is essential for a normal male life.

Lack of specificity of commercially available antisera against muscarinergic and adrenergic receptors.

Commercially available antisera against five subtypes of muscarinic receptors and nine subtypes of adrenoceptors showed highly distinct immunohistochemical staining patterns in rat ureter and stomach. However, using the M(1-4) muscarinic receptor subtypes and alpha(2B)-, beta(2)-, and beta(3)-adrenoceptors as examples, Western blots with membranes prepared from cell lines stably expressing various subtypes of muscarinic receptors or adrenoceptors revealed that each of the antisera recognized a set of proteins that differed between the cell lines used but lacked specificity for the claimed target receptor. We propose that receptor antibodies need better validation before they can reliably be used.