The evaluation of lycopene and cysteamine supplementation effects on sperm and oxidative stress parameters during chilled storage of canine semen

The aim of this study was to evaluate the effects of different concentrations of lycopene and cysteamine on characteristics of sperm, liquid peroxidation and enzymatic activities in seminal plasma of canine semen preserved at 5°C for 72 hr. The semen samples were divided into eight aliquots: control, control sham (dimethyl sulfoxide 5%), lycopene groups (250, 500 and 750 µg/ml) and cysteamine groups (2.5, 5 and 10 mM). Motility, viability, membrane integrity, DNA integrity, total antioxidant capacity (TAC) and malondialdehyde (MDA) levels were evaluated. Progressive motility and total motility were higher with the 500 and 750 µg/ml lycopene concentrations, respectively, compared to the control group and the cysteamine groups following 72 hr of storage in the liquid storage. Motility characteristics, viability and hypo-osmotic swelling test (HOST) percentages were significantly improved in 500 µg/ml lycopene compared to other groups. The 500 and 750 µg/ml lycopene concentrations, respectively, showed significantly reduced percentages of spermatozoa with DNA integrity compared to the control group. The 500 and 750 µg/ml lycopene concentrations, respectively, led to the significant decrease of MDA levels. The 500 µg/ml lycopene enhanced TAC levels after 48 and 72 hr that was not observed in other groups. In conclusion, the findings of this study showed that lycopene supplementation in canine semen extenders improved canine semen parameters and TAC levels and decreased MDA levels in the chilling process.     

Pharmacokinetics of Mirtazapine and Its Main Metabolites after Single Oral Administration in Fasting/Fed Horses

Mirtazapine (MRZ) is a human antidepressant drug that is metabolized, predominantly by the cytochrome P450 enzyme system, to 8-OH mirtazapine (8-OH MRZ) and dimetilmirtazapine (DMR) metabolites. In veterinary medicine, this drug is currently administered to cats and dogs with anorexia, although it could also have applications as an antidepressant, antiemetic, and analgesic agent in these species. The aim of this study was to assess the pharmacokinetics of MRZ and its metabolites DMR and 8-OH MRZ in horses. Six healthy female horses were administered MRZ (2 mg/kg) in fasting and fed states according to a balanced crossover study design. Plasma MRZ and metabolite concentrations were evaluated by high-performance liquid chromatography fluorescence detection method. Pharmacokinetic profiles of MRZ and DMR were similar (detected from 0.5 up to 34 and 48 hours, respectively), with an MRZ AUC_0-N/DMR AUC_0-N ratio range varying between 1.1 and 1.7. Surprisingly, 8-OH MRZ was undetected. Most of the pharmacokinetic parameters were not altered by food, with the exception of the time required to reach maximum concentration; this showed a statistical increase in subjects in the fasting state as compared with the fed state. However, because MRZ is an active substance intended for long-term administration, the slight increase of the time required to reach maximum concentration is not considered to be of any clinical consequence. In conclusion, the pharmacokinetic parameters demonstrated in this study suggest that MRZ is suitable for oral administration in the horse. However, further investigations are required to evaluate both its safety and effectiveness in this animal species.     

Determination of reaction rate parameters for the acid copper chromate fixation reactions on oak (Quercus castaneifolia C. A. Mey) sapwood

Acid copper chromate fixation reactions on oak (Quercus castaneifolia C. A. Mey) sapwood were characterized by at least two distinguished reaction periods which differ in their kinetic behavior, particularly reaction rate. In this research, chemical rate equation parameters were studied in detail as a function of chromium fixation time. Theoretically, the kinetic data were distinguished between the adsorption and reduction reactions and consequently, the rate parameters were determined for each stage distinctly. The obtained results showed that at the investigated thermal range (25–33°C), almost for every 3°C increase in temperature the reaction duration has decreased 20.4?min for the first reaction period and 78?min for the second reaction period. Besides that, in all sample replications, up to 58.3% of hydrogen ions function at the reduction reactions of the initial period, demonstrating that acidity (H⁺ ions) has a major effect on reaction rate constant. Accordingly, adsorption reactions of the hexavalent chromium at the starting point follow a pseudo-first-order kinetic reaction. Different to the adsorption reaction the Cr^VI reduction reaction is exothermic with a measured exothermal energy of 48.2?kJ/mol.