Testicular atrophy after bile duct ligation in chickens

Skeletal Muscle Fibre Type Changes in an Avian Model of Hepatic Fibrosis

We investigated the susceptibility of type I and type II skeletal myofibres to atrophy in hens with hepatic fibrosis induced by bile duct ligation (BDL). Seven hens, approximately 2 years old, were randomly assigned to BDL (n = 4) and sham surgery (SHAM) (n = 3) groups. Mean body weight and mean liver weight as a percentage of mean body weight were significantly lower in the BDL group than in the SHAM group at 4 weeks post surgery (P = 0.002, P = 0.005, respectively). Mean plasma aspartate aminotransferase activity was slightly higher, while total cholesterol (P <0.001), total bilirubin (P = 0.022) and NH₃ (P = 0.048) concentrations were significantly higher in the BDL group than in the SHAM group. Liver lesions were induced in all hens in the BDL group. The weights of the pectoralis (PCT) (P = 0.049) and flexor perforans et perforatus digiti III (FPPD III) muscles (P = 0.006) as a percentage of body weight were significantly decreased in the BDL group. A significantly reduced mean myofibre cross-sectional area in the PCT of BDL hens (P = 0.005) was indicative of atrophy. No significant differences were observed in the fibre type composition of the PCT, supracoracoideus or FPPD III muscles between the SHAM and BDL groups. However, there was an approximate 43% increase in the number of type I fibres in the femorotibialis lateralis of the BDL group and small angular type II fibres and large round type I fibres in this muscle were characteristic of peripheral neuropathy. The results suggest that type II fibres are more susceptible to atrophy than type I fibres in this model of hepatic fibrosis.

Epididymal ultrastructural changes associated with chronic cholestasis after bile duct ligation in adult rats

Testicular atrophy and testesterone insufficiency have been commonly reported associated with chronic liver diseases. Though testosterone dependent, the epididymal changes induced by liver disease have never been studied before. Thus, this study aimed to assess the ultrastructural events in the epididymis of rats with chronic obstructive jaundice. Chronic cholestasis induced many epididymal structural alterations manifested by the reduced tubular diameters, thickening of the tubular basement membrane, and regression of the principal cells. This was accompanied with reduction of principal cell organelles, cytoplasmic vacuolations, nuclear alterations, and stereovilli loss. The results establish that chronic cholestasis causes epididymal structural changes due to androgen deficiency.

Comb Atrophy after Bile Duct Ligation in Chickens

Gross, histological, and immunohistochemical changes in the combs of chickens after bile duct ligation (BDL) are described. Gross reductions in comb size and volume and lower serum testosterone levels were evident in chickens after BDL. Histologically, atrophic combs were characterized by reduced blood capillary diameter, decreased acid mucopolysaccharides, thinning of the stratum germinativum of the epidermis and dermis, and reduced immunostaining intensity of androgen receptors. These results suggest that the affected cells in atrophic combs are androgen targets. BDL caused testicular atrophy in chickens, a primary complication of liver disease, and the resultant low serum testosterone levels subsequently caused atrophy of the comb. In other words, the atrophy of the comb observed in BDL chickens was a secondary complication of liver dysfunction that simulated the effects of liver disease.

Ursodeoxycholic acid alleviates cholestasis-induced histophysiological alterations in the male reproductive system of bile duct-ligated rats

Ursodeoxycholic acid is the most widely used drug for treating cholestatic liver diseases. However, its effect on the male reproductive system alterations associated with cholestasis has never been studied. Thus, this study aimed to investigate the effect of ursodeoxycholic acid on cholestasis-induced alterations in the male reproductive system. Cholestasis was induced by bile duct ligation. Bile duct-ligated rats had higher cholestasis biomarkers and lower levels of testosterone, LH and FSH than did the Sham rats. They also had lower reproductive organs weights, and lower sperm motility, density and normal morphology than those of Sham rats. Histologically, these animals suffered from testicular tubular atrophy, interstitial edema, thickening of basement membranes, vacuolation, and depletion of germ cells. After ursodeoxycholic acid administration, cholestasis-induced structural and functional alterations were significantly ameliorated. In conclusion, ursodeoxycholic acid can ameliorate the reproductive complications of chronic cholestasis in male patients, which represents an additional benefit to this drug.

Autocrine regulation of biliary pathology by activated cholangiocytes

The bile duct system of the liver is lined by epithelial cells (i.e., cholangiocytes) that respond to a large number of neuroendocrine factors through alterations in their proliferative activities and the subsequent modification of the microenvironment. As such, activation of biliary proliferation compensates for the loss of cholangiocytes due to apoptosis and slows the progression of toxic injury and cholestasis. Over the course of the last three decades, much progress has been made in identifying the factors that trigger the biliary epithelium to remodel and grow. Because a large number of autocrine factors have recently been identified as relevant clinical targets, a compiled review of their contributions and function in cholestatic liver diseases would be beneficial. In this context, it is important to define the specific processes triggered by autocrine factors that promote cholangiocytes to proliferate, activate neighboring cells, and ultimately lead to extracellular matrix deposition. In this review, we discuss the role of each of the known autocrine factors with particular emphasis on proliferation and fibrogenesis. Because many of these molecules interact with one another throughout the progression of liver fibrosis, a model speculating their involvement in the progression of cholestatic liver disease is also presented.

Castration inhibits biliary proliferation induced by bile duct obstruction: novel role for the autocrine trophic effect of testosterone

Increased cholangiocyte growth is critical for the maintenance of biliary mass during liver injury by bile duct ligation (BDL). Circulating levels of testosterone decline following castration and during cholestasis. Cholangiocytes secrete sex hormones sustaining cholangiocyte growth by autocrine mechanisms. We tested the hypothesis that testosterone is an autocrine trophic factor stimulating biliary growth. The expression of androgen receptor (AR) was determined in liver sections, male cholangiocytes, and cholangiocyte cultures [normal rat intrahepatic cholangiocyte cultures (NRICC)]. Normal or BDL (immediately after surgery) rats were treated with testosterone or antitestosterone antibody or underwent surgical castration (followed by administration of testosterone) for 1 wk. We evaluated testosterone serum levels; intrahepatic bile duct mass (IBDM) in liver sections of female and male rats following the administration of testosterone; and secretin-stimulated cAMP levels and bile secretion. We evaluated the expression of 17β-hydroxysteroid dehydrogenase 3 (17β-HSD3, the enzyme regulating testosterone synthesis) in cholangiocytes. We evaluated the effect of testosterone on the proliferation of NRICC in the absence/presence of flutamide (AR antagonist) and antitestosterone antibody and the expression of 17β-HSD3. Proliferation of NRICC was evaluated following stable knock down of 17β-HSD3. We found that cholangiocytes and NRICC expressed AR. Testosterone serum levels decreased in castrated rats (prevented by the administration of testosterone) and rats receiving antitestosterone antibody. Castration decreased IBDM and secretin-stimulated cAMP levels and ductal secretion of BDL rats. Testosterone increased 17β-HSD3 expression and proliferation in NRICC that was blocked by flutamide and antitestosterone antibody. Knock down of 17β-HSD3 blocks the proliferation of NRICC. Drug targeting of 17β-HSD3 may be important for managing cholangiopathies.