Pharmacodynamic and Pharmacokinetic Studies on Tetracycline Hydrochloride in Rabbits

Tetracycline is one of the most important groups of antibiotics that have harmful effects on the consumers, therefore the public health safety against its residues represents a significant issue. This study aimed to estimate the effect of tetracycline hydrochloride on some hematological parameters, kidneys function tests as well as liver and breast muscle enzymes with special reference to the supposed withdrawal time of this drug in different rabbits’ tissues (kidney, liver and muscles), following oral dose of tetracycline using High Performance Liquid Chromatography. Tetracycline was administrated to eighteen rabbits directly into the stomach at a dose of 35 mg/kg BW once daily for five successive days. Samples were collected on the 1st, 3rd, 7th, 14th, 21st and 28th days after the last oral dose. The results revealed that, tetracycline caused a significant increase in the uric acid, urea, creatinine, alkaline phosphatase (ALP), aspartate aminotransferase (AST), alanine aminotransferase (ALT), creatine phosphokinase (CPK) and lactate dehydrogenase (LDH) activities with no significant changes in the hematological parameters when compared with the control group. The residues remained in the liver and kidney for 7 days, while in muscles for 3 days only after the last oral dose of the drug. In conclusion, the disturbances in the biological parameters occurred by tetracycline administration in rabbits was transient and returned to normal after 7 days of last treatment. The withdrawal time of tetracycline was 14 days from the rabbit's tissues

Effects of Oral Administration of Atorvastatin or Fenofibrate on Hyperlipidemia Induced by Betamethasone Dipropionate Injection in Rabbits

Betamethasone, a fluorinated and synthetic steroid, is a commonly used glucocorticoid. To our knowledge, no available studies exist concerning the hyperlipidemic effect of betamethasone dipropionate (BDP) in rabbits. Therefore, the current study was conducted to highlight the effects of intramuscular injection of BDP on lipid profile in rabbits, investigate the possible mechanism underlying the produced effects and evaluate the possible antihyperlipidemic effect of atorvastatin (ATR) and fenofibrate (FFB). For this purpose, twenty male New Zealand rabbits were classified into control, BDP (0.5 ml/kg B.wt/ IM/day/single dose), BDP+ATR; rabbits were IM injected with BDP, then they were orally given ATR (1.9 mg./kg. B.wt./ once/ day/ month) and group IV (BDP+FFB); rabbits were IM injected with BDP then they were orally given FFB (7.5 mg/kg B.wt/ once/ day/ month). The obtained result revealed that single IM injection of BDP produced a significant elevation in triglycerides, total cholesterol, LDL level with a significant decline in HDL in comparison to control group on the 3rd,7th,14th, 21st, 30th day of the experiment. On the 30th day of the experiment there was an increase in the ALT, AST, MDA, VCAM-1 as well as a significant decrease in TAC. Furthermore, BDP induced a significant increase in HMG-COA reductase gene expression and a significant decrease in lipoprotein lipase gene expression. Oral administration of ATR or FFB concurrently with BDP for a month succeeded in reducing the hyperlipidemia induced by BDP in rabbits