Diurnal and seasonal changes in endogenous melatonin levels in the blood plasma in dogs.

This paper describes research on the levels of endogenous melatonin (MLT) in the blood serum in dogs in different seasons (March, June, September, December) and at different times of day (11:00, 12:00, 23:00, 24:00 and 1:00), using immunoassay method. Blood samples were collected in the diurnal cycle, in consecutive seasons. The conducted studies show that MLT levels undergo clear changes in both the diurnal cycle, as well as in seasonal one in this species.

Pharmacokinetics of tylosin in broiler chickens.

Biological availability and pharmacokinetic properties of tylosin were determined in broiler chickens after oral (p.o.) and intravenous (i.

Bacterial resistance to quinolone antibiotics in Poland.

The resistance of 167 pathogenic bacteria of animal origin to quinolones was determined by the disc diffusion method, and by the minimum inhibitory concentration (MIC) test. The highest resistance of Escherichia coli was found to be against nalidixic acid (NA), 49.1% and flumequine (FLU), 38.

Xylazine impairs the anticonvulsant activity of conventional antiepileptic drugs in mice.

In this study the influence of xylazine upon the threshold of electrically-induced convulsions and the anticonvulsant action of diazepam, phenobarbital and phenytoin was studied in mice. All drugs were given as solutions intraperitoneally (i.p.

Influence of D-cycloserine on the anticonvulsant activity of phenytoin and carbamazepine against electroconvulsions in mice.

Purpose: D-Cycloserine (DCS) is a high-efficacy partial agonist at the strychnine-insensitive glycine modulatory site within the N-methyl-D-aspartate (NMDA)-receptor/ionophore complex. Previous studies demonstrated that DCS exhibits anticonvulsant activity in a variety of experimental epilepsy models. In this study, we determined the influence of DCS in subprotective doses on the anticonvulsant action of phenytoin (PHT) and carbamazepine (CBZ) in mice.