Automated high-performance liquid chromatographic method for determination of furosemide in dog plasma

An automated high-performance liquid chromatographic method for the determination of the diuretic drug furosemide has been established. Dog plasma was injected directly into a two-column system with a BSA—ODS (ODS column coated with bovine serum albumin) precolumn and a C₁₈ analytical column for the separation of furosemide. The two columns were automatically switched. Furosemide remained trapped on the precolumn while proteins were eluted to waste. After column switching, furosemide was washed onto the analytical column and analysed without interference. The greatest advantage of the method is its easy performance without manual sample preparation; it requires no extraction or deproteinization. The method allows determination of 0.1–10 μg/ml of furosemide with accuracy and precision comparable with previously reported values. The coefficients of variation obtained from replicate measurements of 1 μg/ml and 5 μg/ml samples were 1.65% and 2.40%, respectively. This method was used to measure the plasma levels of furosemide in beagle dogs to whom the drugs was administered, as a reference, in a toxicological study.     

Differences between horse selection based on two forms of osteochondrosis in fetlock

Horses lose potential opportunities because of health problems. Available breeding strategies are not effective enough, probably also because of the different definition used and its genetic usefulness. The aim of the study was to compare the genetic background estimated by the genome-wide association study (GWAS) for osteochondrosis using two different scaling osteochondrosis (OC)/healthy and osteochondrosis dissecans (OCD)/healthy systems for evaluating the disease status of investigated fetlock joints. Two hundred one Warmblood horses trained for performance tests (87 stallions and 114 mares) were phenotyped and genotyped. Four fetlock x-ray images per horse were collected using the RTG Girth HF 80 and Vet Scan ray 3600. The DNA of each horse was genotyped using the BeadChip 70K. To identify SNPs that significantly affect the probability of osteochondrosis, two different methods were applied: the Cochran-Armitage test based on an additive mode of inheritance and logistic regression. The genetic background for osteochondrosis, expressed in the number of SNPs found with significant associations with osteochondrosis, was higher by evaluation in the scale of OCD/healthy horses (16 SNPs on several chromosomes mainly on the ECA1 and ECA10) than OC/healthy (2 SNPs on the ECA15 and one SNP on the ECA10). Detailed definition of osteochondrosis is needed in breeding and in veterinary practice. The genetic background for osteochondrosis and osteochondrosis dissecans seems not the same. Suggestive SNPs could be the candidate markers for osteochondrosis but should be checked on a larger population before usage.     

Endothelin-induced mobilization of Ca2+ and the possible involvement of platelet activating factor and thromboxane A2

Endothelin (ET) caused transient and sustained elevations of cytosolic free Ca2+ concentrations ([Ca2+]i) in cultured rat and rabbit vascular smooth muscle cells (VSMC). Specific platelet activating factor (PAF) antagonists (CV-6209 and WEB-2086) and arachidonic acid (AA) cascade blockers (chlorpromazine, indomethacin, CV-4151 and AA-2414) potently inhibited the ET-induced increase in [Ca2+]i. Additionally, these compounds inhibited the PAF-induced increase in [Ca2+]i. These results suggest that PAF and thromboxane A2 (TXA2) may be involved in the mechanism of ET-induced mobilization of Ca2+ in cultured rat and rabbit VSMC.     

Changes of enzyme activity in the rat liver at different age in circadian cycle

Most of the biological processes in the living organisms of both animals and man are known to be of rhythmical nature. Variability of enzymatic activity in circadian cycle depends on many factors among other on age, sexual maturity, diet as well as medication. The results obtained in our studies indicate, that the activity changes of acid phosphatase and ATP-ase Mg++ dependent in the liver of all the examined age groups were of 24 hour circadian rythm. As to the acid phosphatase activity the results of this experiments showed that in circadian cycle in all examined age groups there is only one peak of elevated activity. ATP-ase Mg++ dependent showed two activity peaks appearing at the same hour both in 30 and 60 days old animals. It should be noticed that the activities of ATP-ase Mg++ dependent in 100 day old animals were two times higher than in 30 and 60 days old rats.     

Responses of grass pea seedlings to salinity stress in in vitro culture conditions

Physiological and molecular mechanisms of adaptation to abiotic stresses of grass pea (Lathyrus sativus L.) are still poorly understood. Responses of four genotypes of grass pea to salinity stress in tissue culture conditions were investigated at early seedling growth stages. Salinity stress was induced in the agar media by adding 0, 50, 100 and 200 mM of NaCl. Germination and seedling emergence percentage was not significantly affected by 50 and 100 mM of NaCl. However, NaCl in 200 mM concentration lowered level of these parameters. Generally, exposure to NaCl stress significantly reduced length of grass pea seedling organs (root and shoot) but did not influence the content of dry weight in shoots and increased it in the roots in two cases. Increasing salt concentration decreased integrity of cellular membranes both in root and shoot tissues. Higher accumulation of phenolic compounds and significant changes in activity of antioxidant enzymes (peroxidase and catalase) were observed in the roots but not in the shoots. Similarly, the content of proline increased mostly in the roots from moderate (100 mM) salinity conditions. Adverse conditions did not resulted in alterations in photosynthetic pigments content of any tested genotypes. The better performance of shoots than roots may result from in vitro conditions in which experiments were conducted.