Cirrhosis induced by bile duct ligation alleviates acetic acid intestinal damages in rats: Involvements of nitrergic and opioidergic systems

Bone healing around titanium implants in a preclinical model of bile duct ligation-induced liver injury

Objectives

Chronic liver disease increases the risk for periodontal disease and osteoporotic fractures, but its impacts on bone regeneration remain unknown. Herein, we studied the impact of liver cirrhosis on peri‐implant bone formation.

Material and Methods

A total of 20 male Wistar rats were randomly divided into two groups: one with the common bile duct ligated (BDL) and the respective sham‐treated control group (SHAM). After four weeks of disease induction, titanium mini‐screws were inserted into the tibia. Successful induction of liver cirrhosis was confirmed by the presence of clinical symptoms. Another four weeks later, peri‐implant bone volume per tissue volume (BV/TV) and bone‐to‐implant contact (BIC) were determined by histomorphometric analysis.

Results

Peri‐implant bone formation was not significantly different between the SHAM and BDL groups. In the cortical compartment, the median percentage of peri‐implant new bone was 10.1% (95% CI of mean 4.0–35.7) and 22.5% (13.8–30.6) in the SHAM and BDL groups, respectively (p = .26). Consistently, the new bone in direct contact with the implant was 18.1% (0.4–37.8) and 23.3% (9.2–32.8) in SHAM and BDL groups, respectively (p = .38). When measuring the medullary compartment, the new bone area was 7.1% (4.8–10.4) and 10.4% (7.2–13.5) in the SHAM and BDL groups, respectively (p = .17). Medullary new bone in direct contact with the implant was 10.0% (1.2–50.4) and 20.6% (16.8–35.3) in SHAM and BDL groups, respectively, and thus comparable between the two groups (p = .46).

Conclusions

Bile duct ligation has no significant impact on the early stages of peri‐implant bone formation.

Endogenous Opiates and Behavior: 2018

This paper is the forty-first consecutive installment of the annual anthological review of research concerning the endogenous opioid system, summarizing articles published during 2018 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides and receptors as well as effects of opioid/opiate agonists and antagonists. The review is subdivided into the following specific topics: molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors (2), the roles of these opioid peptides and receptors in pain and analgesia in animals (3) and humans (4), opioid-sensitive and opioid-insensitive effects of nonopioid analgesics (5), opioid peptide and receptor involvement in tolerance and dependence (6), stress and social status (7), learning and memory (8), eating and drinking (9), drug abuse and alcohol (10), sexual activity and hormones, pregnancy, development and endocrinology (11), mental illness and mood (12), seizures and neurologic disorders (13), electrical-related activity and neurophysiology (14), general activity and locomotion (15), gastrointestinal, renal and hepatic functions (16), cardiovascular responses (17), respiration and thermoregulation (18), and immunological responses (19).

Anticonvulsant Effects of Thalidomide on Pentylenetetrazole-Induced Seizure in Mice: A Role for Opioidergic and Nitrergic Transmissions

Although accumulating evidence indicates that the immunomodulatory medication thalidomide exerts anticonvulsant properties, the mechanisms underlying such effects of thalidomide are still unknown. Our previous preclinical study suggested that nitric oxide (NO) signaling may be involved in the anticonvulsant effects of thalidomide in a mouse model of clonic seizure. Additionally, several studies have shown a modulatory interaction between thalidomide and opioids in opioids intolerance, nociception and neuropathic pain. However, it is unclear whether opioidergic transmission or its interaction with NO signaling is involved in the anticonvulsant effects of thalidomide. Given the fact that both opioidergic and nitrergic transmissions have bimodal modulatory effects on seizure thresholds, in the present study we explored the involvement of these signaling pathways in the possible anticonvulsant effects of thalidomide on the pentylenetetrazole (PTZ)-induced clonic seizure in mice. Our data showed that acute administration of thalidomide (5-50 mg/kg, i.p., 30 min prior PTZ injection) dose-dependently elevated PTZ-induced clonic seizure thresholds. Acute administration of low doses (0.5-3 mg/kg, i.p., 60 min prior PTZ) of morphine exerted anticonvulsant effects (P < 0.001), whereas higher doses (15-60 mg/kg, 60 min prior PTZ) had proconvulsant effects (P < 0.01). Acute administration of a non-effective anticonvulsant dose of morphine (0.25 mg/kg) prior non-effective dose of thalidomide (5 mg/kg) exerted a robust (P < 0.01) anticonvulsant effect. Administration of a non-effective proconvulsant dose of morphine (7.5 mg/kg) prior thalidomide (5 mg/kg) didn't affect clonic seizure thresholds. Acute administration of a non-effective dose of the opioid receptor antagonist naltrexone (1 mg/kg, i.p.) significantly prevented anticonvulsant effects of thalidomide (10 mg/kg, i.p.). Pretreatment with non-effective dose of the NO precursor L-arginine (60 mg/kg, i.p.) significantly (P < 0.01) reduced the anticonvulsant effects of combined low doses of morphine (0.25 mg/kg) and thalidomide (5 mg/kg). Conversely, pretreatment with non-effective doses of either non-selective (L-NAME, 5 mg/kg, i.p.) or selective neuronal (7-nitroindazole, 30 mg/kg, i.p.) NO synthase (NOS) inhibitors significantly augmented the anticonvulsant effects of combined low doses of thalidomide and morphine, whereas the inducible NOS inhibitor aminoguanidine (100 mg/kg, i.p.) did not exert such effect. Our results indicate that opioidergic transmission and its interaction with neuronal NO signaling may contribute to the anti-seizure activity of thalidomide in the mice PTZ model of clonic seizure.

Hemodynamic characteristics of biliary cirrhosis in rats

AIM

To elucidate the hemodynamic characteristics of biliary cirrhosis in common bile duct ligated rats.

METHODS

Biliary cirrhosis was induced in rats by common bile duct ligation (CBDL). Rats were divided into a sham group and a CBDL group. At the end of 4 weeks, portal pressure (PP) and mean arterial pressure (MAP) were measured directly via catheters. Liver or spleen coefficient was the ratio of liver weight or spleen weight to body weight. Proliferation of fibrous tissue was evaluated by Masson staining.

RESULTS

At the end of 4 wk, the liver of CBDL rats was yellow in color and enlarged. The surface of some livers was scattered with numerous nodules. Masson staining indicated extensive proliferation of fibrous tissue and pseudolobule. PP of CBDL rats was increased and MAP was decreased compared with sham rats. There was a significant positive correlation between PP and MAP (R² = 0.9096). PP of rats with severe ascites was lower than that of rats with mild or no ascites.

CONCLUSION

After 4 wk of CBDL, liver cirrhosis and portal hyper-tension develop. PP is determined by the degree of ascites and MAP.