Effect of Prolactin on Biochemical and Morphological Parameters of Rabbit Liver in Warm Ischemia.

BACKGROUND: The aim of the study was to assess the degree of liver damage in a rabbit perfused with histidine-tryptophan-ketoglutarate (HTK [Custodiol]) solution with and without the presence of prolactin (PRL) based on biochemical studies in perfundate and ultrastructural analysis of hepatocytes. MATERIALS AND METHODS: The experiment was carried out on rabbits. Liver ischemia was used in the study, based on Pringle's maneuver. About 70% of the rabbit liver lobes were perfused with HTK with or without the addition of PRL (2.5µg/g liver/h) under ischemic conditions for 2 hours. In the perfundate, the activity of enzymes alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), γ-glutamyl transpeptidase (GGT), and lactate concentration were determined. Liver biopsies were collected for histopathologic evaluation under an electron microscope. RESULTS: The addition of PRL to the HTK significantly reduced the leakage of enzymes from the liver to perfundate compared with the control group without PRL. The activity of ALT, AST, LDH, and GGT in the perfundates obtained after 2-hour perfusion with HTK-PRL solution was lower when compared with activity of the same parameters determined in perfundates with liver perfused with HTK without PRL. The area under the curve (AUC0-2h) calculated for GGT, LDH, and lactates was significantly higher after perfusion with the HTK than with HTK with the addition of PRL. In the study group, bile was secreted throughout the whole experiment. The morphological confirmation of these results was obtained by means of transmission microscopy. CONCLUSION: PRL added to the preservation solution significantly inhibits the process of liver cell cytolysis, which may suggest its hepatoprotective effect.

Pharmacokinetics of calcium from calcium supplements in healthy volunteers.

Calcium supplementation is widely used in deficiency status and as an adjuvant in the treatment of osteoporosis. The objective of this study was to compare the oral bioavailability of calcium from tablets containing calcium fumarate to that of calcium gluconate. Twelve healthy volunteers participated in the study. Single-dose, two-treatment, two-sequence-crossover, randomized design test methodology was applied. The tablets were prepared by direct compression and were subjected to tests: drug content, hardness, friability, disintegration time and in vitro dissolution studies. The preparations were compared using pharmacokinetic parameters such as the area under the plasma concentration - time curve AUC((0-11)), peak plasma concentration C(max), time to reach maximum plasma concentration T(max). No statistically significant difference was observed for any of the parameters, and the 90% confidence intervals calculated for the ratio of the logarithmically transformed AUC((0-11)) values of both formulations were within the bioequivalence limit of 0.80-1.25. It can be concluded that the two tablet preparations of calcium are likely to be bioequivalent.

Pharmacokinetics of selenium following oral administration selenium preparation in rabbits.

The aim of study was to investigate the bioavailability of selenium after oral administration of selenium yeast. As a reference preparation was used sodium selenite. The preparations were investigated in rabbits, according to a randomized two way crossover design in the fasted state. Each animal was given selenium preparation in the form of the single oral dose 0.5 mg Se/kg body weight. A washout period of one week separated both treatment periods. The selenium concentration was determined in serum spectrofluorometry. The divalent equation of one-compartment model was the simplest formula describing the course of selenium changes in serum of rabbits and giving the pharmacokinetic parameters. Pharmacokinetic variables (mean maximum plasma concentration, mean time to reach maximum plasma concentration, and the mean area under the plasma concentration-time curve) were not statistically different for the two preparations. It can be concluded that the two selenium preparations are likely to be bioequivalent.