H3 Propranolol serum levels following lidocaine administration in rats with CCL4 — induced liver damage

Review of experimental models for inducing hepatic cirrhosis by bile duct ligation and carbon tetrachloride injection

PURPOSE

To present a review about a comparative study of bile duct ligation versus carbon tetrachloride Injection for inducing experimental liver cirrhosis.

METHODS

This research was made through Medline/PubMed and SciELO web sites looking for papers on the content "induction of liver cirrhosis in rats". We have found 107 articles but only 30 were selected from 2004 to 2011.

RESULTS

The most common methods used for inducing liver cirrhosis in the rat were administration of carbon tetrachloride (CCl4) and bile duct ligation (BDL). CCl4 has induced cirrhosis from 36 hours to 18 weeks after injection and BDL from seven days to four weeks after surgery.

CONCLUSION

For a safer inducing cirrhosis method BDL is better than CCl4 because of the absence of toxicity for researches and shorter time for achieving it.

Clonidine changes lidocaine free concentrations in rat myocardium without affecting heart function measured by echocardiography

Lidocaine is a local anaesthetic widely used in regional and epidural anaesthesia. Clonidine a alpha2-adrenergic agonist is an antihypertensive agent, regulating the production of catecholamines (epinephrine and norepinephrine) and added to local anesthetic infusions in order to improve postoperative analgesia. The aim of the study was to investigate the influence of clonidine co-administration on the binding of 14C lidocaine to rat serum and heart tissue protein as well as its pharmacodynamic effects in the heart. Four groups of Wistar rats (n=7) were used; Groups I and II received 4 mg/kg lidocaine i.m. Groups III and IV received lidocaine and 1 microg/kg clonidine i.m. In group I and III fifteen minutes and in groups II and IV thirty minutes after the initial treatment, ultrasound examination of heart function (heart rate, diameter of left ventricle in systole and diastole, ejection fraction) was performed. The animals were then sacrificed in all groups. Lidocaine free fraction in serum and heart was evaluated via ultrafiltration. The kinetics of lidocaine was altered by clonidine co-administration probably by mechanisms related to protein binding alterations. However, the pharmacokinetic interactions were not accompanied by changes of pharmacodynamic parameters including those of heart function as measured by echocardiography.