Analysis of Interactions Between Components of Selected Solution for Organ Perfusion and Preservation.

BACKGROUND: In the literature there is a great deal of information about the activity of liquid preservatives and the solutions used to modify them; however, there is no information about the possibility of interactions between them during multiorgan retrieval. The aim of the study was to analyze the possibility of reactions between the components of Biolasol and histidine-tryptophan-ketoglutarate (HTK). Biolasol is the first Polish liquid preservative intended for rinsing kidneys, livers, and pancreases by simple hypothermia. HTK is a cardioplegic fluid used in organ preservation of hearts, livers, kidneys, pancreases, and lungs. METHODS: Biolasol and HTK solution were used for the tests. The preservatives were mixed together at 1:1, 0.25:0.75, and 0.75:0.25 ratios. The volume of mixtures to be analyzed was 500 mL. The prepared systems were stored in a refrigerator (4°C) protecting against light. The systems were subjected to physicochemical analysis involving pH, density, viscosity, buffer capacity, osmolarity, and absorbance measurements as well as visual and microscopic assessment at time intervals: immediately after mixing (t = 0) and after 12, 24, 48, and 72 hours. RESULTS: The analysis suggests that interactions between solution components can occur and have a positive effect on storage time and effectiveness of organ rinsing. CONCLUSIONS: The use of Biolasol and HTK in multiorgan retrieval is safe.

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.

Comparison of Vascular Endothelial Growth Factor Concentration in Porcine Kidneys Removed From Living Donors After Cardiac and Brain Death.

The aim of this paper was to describe the differences in vascular endothelial growth factor (VEGF) concentration in porcine kidneys removed from living donors (group I), donors after prior induction of brain death by brain herniation (group II), and donors after cardiopulmonary arrest (group III). The groups consisted of 6 animals which underwent dual renal removal procedures; kidneys were rinsed, stored for 24 hours at 4°C and rinsed again. Renal specimens (4g) were collected before and after perfusion (time 0 and 1), after 12 hours (time 2), and after reperfusion (time 3). A Western blot was used to evaluate VEGF concentration in collected tissues homogenates. Additionally, the levels of VEGF, interleukin 1ß, tumor necrosis factor α, and endothelial nitric oxide synthase (eNOS) were detected with enzyme-linked immunosorbent assays. Directly after the removal procedure, no significant differences in VEGF levels (IOD) were observed depending on the donor (moderate levels were observed in all groups: 1.51 in group I, 1.48 in group II, and 1.35 in group III). As a consequence of perfusion and 12 hours of storage, a stable concentration in groups I and III was observed with a gradual increase of VEGF levels in group II (1.23, 2.08, and 1.67 in the respective groups at time 1; 1.49, 2.12, and 1.63 in the respective groups at time 2). After the following 12 hours, a statistically significant (P < .05) higher level of VEGF was observed in group II (2.34) in comparison to groups I and III (1.58 and 1.81, respectively). In group I, a correlation between VEGF concentration and IL-1ß was observed, while in group II there was correlation between VEGF and eNOS levels.

Effect of Recombinant Human Prolactin Addition to Biolasol Solution on Biochemical Indicators in Perfundates of Porcine Kidneys.

BACKGROUND: The influence of recombinant human prolactin (rh-PRL) added to Biolasol solution (concentration 1 µg/L) on selected markers (pH, osmolarity, Na(I) and K(I) concentration) and enzymatic activity (alanine aminotransferase [ALT], aspartate aminotransferase [AST], and lactate dehydrogenase [LDH]) in perfundates was investigated during flushing and preservation of the isolated porcine kidneys. METHODS: The pH, osmolarity, concentration of K(I) and Na(I), and enzymatic activity were determined in perfundates collected after the 5th and 30th minutes of perfusion, after 24 hours of organ preservation, and in the 5th and 30th minutes of reperfusion. Kidneys had been flushed and stored in Biolasol (control group) and in Biolasol with rh-PRL (experimental group). Obtained results were compared with Biolasol solution. RESULTS: In the experimental group, the decrease in pH value in the 5th minute of reperfusion was noted. There was an increase in K(I) concentration, and Na(I) concentration decreased in the 5th and 30th minutes of reperfusion. ALT activity during perfusion and preservation increased, whereas at the 5th and 30th minutes of reperfusion it decreased. AST activity increased during perfusion and preservation and decreased in the 5th and 30th minutes of reperfusion. LDH activity was increased but decreased in the 5th minute of reperfusion. CONCLUSIONS: Addition of 1 µg/L rh-PRL to Biolasol solution decreases pH and osmolarity values; influences Na(I) and K(I) concentration; increases ALT, AST activity during perfusion and preservation of organs; and decreases ALT, AST activity during reperfusion.

Endothelial Nitric Oxide Synthase and Endothelin-1 Expression in the Early Post-Porcine Kidney Autotransplantation Period.

BACKGROUND: The aim of this study was the assessment of endothelial nitric oxide synthase (eNOS) and endothelin-1 (EDN-1) expression in porcine kidneys on the 14th and 30th days after the autotransplantation procedure. METHODS: The research was conducted on 12 animals that underwent a left renal transplantation procedure with further standardized rinsing and 24-hour storage in 4°C; subsequently, the kidneys were implanted in the right retroperitoneal space after right-sided nephrectomy. Removed kidneys were examined (group 0). Six randomly chosen animals (group 1) were under observation for 14 days and 6 others (group 2) for 30 days. RESULTS: After these observation periods, euthanasia was performed on the animals and 4-g samples were collected from the renal cortex and medulla. The Western blot technique was used to detect the eNOS and EDN-1 expression at the protein level. The obtained results are presented as absolute values of integrated optical density. Stable graft function was observed in all animals from the 2nd day after the procedure. eNOS in group 1 reached the mean value of 1.064 and was statistically significantly lower than in group 2 (2.085) or in the control group 0 (3.318). In the case of EDN-1 expression on 14th day after transplantation, the medium level was reported (0.248), which was similar to group 0 (0.216), whereas group 2 presented values 2 times higher (0.743). CONCLUSIONS: A lowered eNOS level in the organ was observed on the 14th day after autotransplantation of a pig kidney; further enzyme normalization is associated with increased EDN-1 expression.

Biolasol: novel perfusion and preservation solution for kidneys.

INTRODUCTION: Biolasol solution (Pharmaceutical Research and Production Plant "Biochefa," Sosnowiec, Poland) is a novel extracellular perfusion and ex vivo hypothermic kidney preservation solution. It ensures maintenance of homeostasis, reduces tissue edema, has low viscosity, and allows the graft to preserve structural and functional integrity. It minimizes ischemia-reperfusion damage. METHODS: Perfundates from control and transplanted kidneys flushed with Biolasol or ViaSpan solutions (Arkas, Warszawa, Poland) were analyzed. Parameters of serum and urine collected from 12 pigs after auto-transplantation were also analyzed. Renal medulla was investigated for structural alterations by analyzing hematoxylin and eosin-stained slides. The mean survival time of pigs after the auto-transplantation procedure was the measure for the novel Biolasol solution effectiveness. RESULTS: We observed a statistically significant decrease in marker enzyme levels alanine transaminase, aspartate transaminase, lactic dehydrogenase, and ions (Na and K) in pigs with grafts flushed with Biolasol. Histopathologic examination revealed that the renal cortex structure was not damaged after the use of Biolasol solution. CONCLUSION: Biolasol solution protects kidneys against ischemia damage and does not differ significantly from the "golden standard" ViaSpan solution.

Comparison of endothelial nitric oxide synthase and endothelin-1 levels in kidneys removed from living pigs after cardiac arrest and brain death.

OBJECTIVES: The aim of this paper was to describe differences between levels of endothelial nitric oxide synthase (NOS-3) and endothelin-1 (ET-1) in swine kidneys removed from living donors (group I) and after inducing brain death by brain herniation (group II) and cardiac arrest (group III). METHODS: Each group consisted of 3 animals who underwent dual renal removal procedure; kidneys were further rinsed according to standardized procedure with Biolasol perfusion liquid, stored for 24 hours (4°C), and rinsed again. Renal specimens of 4 g mass, including renal cortex and medulla, were collected before and after perfusion (times 0 and 1), after 12 hours (time 2), and after reperfusion (time 3). Enzyme-linked immunosorbent assay was used to describe levels of NOS-3 and ET-1 in collected tissues homogenates. Mann-Whitney U test was used to compare results in groups in relation to total protein content (ng/mg), and the correlation between the 2 substances was measured with the use of Spearman rho. RESULTS: Group I presented low and stable levels of NOS-3 in all time intervals (averages, 0.73, 0.99, 0.52, and 0.89, respectively). Level sof ET-1 were similar (0.87, 0.63, 0.69, and 0.86, respectively), and significant correlation between levels of the 2 substances was observed. Increased levels of NOS-3 (1.89 and 1.86) and ET-1 (1.38 and 1.49) were observed directly after removal in groups II and III and further maintained during organ storage. No correlation in group I was observed, and after perfusion significantly lower level of NOS-3 was observed in kidneys removed after brain death in relation to group III (1.77 vs 2.60). CONCLUSIONS: The lowest and stable levels of NOS-3 and ET1 during storage were observed in kidneys removed from living donors. Levels of analyzed substances in this group showed correlation in subsequent time intervals.

Toll-like receptors 2 and 4 in pigs' kidneys early after autotransplantation procedure.

OBJECTIVES: The aim of this paper was to evaluate mRNA expression of Toll-like receptors 2 (TLR2) and 4 (TLR4) and the adaptor protein myeloid differentiation primary-response protein 88 (MyD88) in pigs' kidneys 14 and 30 days after autotransplantation. METHODS: The research was conducted on 12 animals that underwent left renal transplantation procedure with further standardized rinsing with Biolasol solution and 24 hours' storage in 4°C; subsequently the kidneys were implanted in the right retroperitoneal space after right-side nephrectomy. Six randomly chosen animals (group I) were under observation for 14 days, the other 6 (group II) for 30 days. After these observation periods, the animals were killed and 4-g samples were collected from the renal cortex and medulla. RESULTS: Expression of mRNA in homogenates of collected samples were determined with the use of reverse-transcription polymerase chain reaction analysis. Obtained results in both groups, presented in relation to GAPDH, were compared with the use of Mann-Whitney U test. Stable graft function was observed in all animals from the 2nd day after the procedure. TLR2 in group I reached the mean value of 3.64 and was statistically significantly higher than in group II (2.19). Inverse proportion was observed in case of mRNA for TLR4: group II presented 2 times higher value than group I (0.25 vs 0.11). Similarly, significant difference was observed in MyD88 (group I, 0.067; group II, 0.45). CONCLUSIONS: At 14 days after autotransplantation of a pig kidney, mRNA expression for TLR2 is dominant; later, expression increases for TLR4 and MyD88.

The effect of HTK solution modification by addition of thyrotropin and corticotropin on biochemical indices reflecting ischemic damage to porcine kidney.

INTRODUCTION: The aim of our study was to evaluate the impact of perfusion with HTK (histidine-tryptophan-ketoglutarate, Custodiol®, Dr. Franz Kohler Chemie, Germany) solution, modified by the addition of porcine thyroid-stimulating hormone (TSH) and corticotropin (ACTH), on selected biochemical parameters of porcine renal damage within 24 and 48 hours after the onset of cold ischemia time. METHODS: Each study group consisted of 10 adult pigs. During harvesting the kidneys were rinsed with Ringer solution (group 1), HTK (group 2), HTK-TSH (1 µg/dL) or HTK-ACTH (1 µg/dL) in groups 3 and 4. The solutions were cooled to 4°C-6°C. Within 30 minutes of the first perfusion, the discharged fluid was clear and the kidneys cooled to 4°C. The levels of lactate dehydrogenase, asparagine and alanine aminotransferases, lactates, total protein, potassium, calcium, and pH were determined in the perfusate. After 24 and 48 hours the rinsing procedure and the above-mentioned tests were repeated. Differences between the means of 2 independent samples were tested with a nonparametric Mann-Whitney U test. RESULTS: As the result of hormone addition, in both time intervals it was possible to observe considerably lower protein concentrations (g/L) in perfusates compared with HTK solution, without an addition. At 24 hours, we measured following values: 36 ± 4, 8 ± 3 and 6 ± 1 versus 48 hours, 34 ± 1, 2 ± 1, and 4 ± 1 in groups 2, 3, and 4. A similar pattern was observed with LDH (U/L) at 48 hours: 662 ± 89, 374 ± 151, and 386 ± 111, respectively. Lactate concentrations (mmol/L) were then significantly higher: 1.4 ± 0.3 in the TSH group and 1.2 ± 0.5 in the ACTH group as opposed to 0.2 ± 0.1 in unmodified HTK group. CONCLUSION: We observed the possibility of cytoprotective actions of TSH and ACTH addition to the perfusion fluid during cold ischemia, positive effects that were especially visible upon prolonged 48-hour storage.

Effect of iodine-enriched yeast supplementation of diet on performance of laying hens, egg traits, and egg iodine content.

The aim of the study was to evaluate the effect of iodine yeast (I-yeast) supplementation on the performance, egg traits, and iodine content of eggs of laying hens. The experiment was conducted as a completely randomized design. A total of 60 laying hens (Hy-Line Brown), 25 wk of age, was divided into 3 groups (4 replicates), and a feeding experiment was conducted for 12 wk. The concentrations and forms of iodine added to the basal diet were as follows: control group, 1 mg of iodine/kg of feed, Ca(IO(3))(2)•H(2)O; experimental groups E1 and E2, 1 and 2 mg of iodine per kilogram of feed, I-yeast, respectively. The iodine yeast did not significantly affect BW gain. Lower level of hen day egg production for groups E1 and E2 was not confirmed statistically; however, it was probably the consequence of low replication. Feed intake was the lowest in the E1 group and feed conversion rate was the highest in the E2 group. Furthermore, the egg and albumen weight was the highest in the group supplemented with 2 mg/kg of iodine from I-yeast (P < 0.05). The concentration of iodine in the egg yolk from groups E1 and E2 was respectively about 80 and 90% higher, compared with the control group. Eggshells from the group fed with 2 mg/kg of I-yeast contained almost 3 times more iodine than eggshells from the control group. The results suggest that iodine yeast supplementation in the diet of laying hens is an effective method for increasing iodine concentration in eggs and thus could contribute to elimination of iodine deficiency disorders in humans consuming iodine-enriched eggs.

Hepatoprotective effect of prolactin and cysteine contained in perfusion and preservation solutions on porcine liver stored in simple hypothermia.

INTRODUCTION: The aim of our study was to determine the results of histidine-tryptophan-ketoglutarate (HTK) solutions modified by the addition of the antioxidant cysteine (Cys), and of prolactin (PRL) on storage of isolated porcine livers. METHODS: We measured in the media of isolated livers stored for 24 hours in HTK (control group) or modified HTK+Cys (0.3 mmol/L)+PRL (3 IU/L study group) the amounts of aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH), lactic acid as well as Ca (II), Mg (II), Na (I) and K (I) ions during a 30-minute perfusion after 24 hours of storage. RESULTS: All tested markers were released more slowly into HTK+Cys+PRL with less release of K(I) and Mg(II) and greater of Na(I) and Ca(II) ions. CONCLUSIONS: Addition of the Cys and PRL to HTK positively affected 24-hour storage of isolated livers.

Evaluation of cysteine effect on redox potential of porcine liver preserved by simple hypothermia.

INTRODUCTION: Cysteine (cys), a thiol amino-acid, is involved in de novo glutathione (GSH) synthesis in the extra- and intracellular space. It is also probably involved in the anaerobic glycolysis process. Both these facts may affect the metabolic condition of the liver preserved by simple hypothermia for transplantation. The aim of the study was to verify whether cysteine addition to histidine-tryptophan-ketoglutarate (HTK) organ preservation solution showed a positive effect on liver redox potential after 12-hour preservation in simple hypothermia. MATERIALS AND METHODS: After collecting livers of Great White breed pigs that underwent 30 min of warm ischemia, before 30-min perfusion and cooling to 4°C with modified HTK solution containing cysteine prior to 12 h of preservation. Activity of glutathione reductase (GR), glutathione peroxidase (GPx), and superoxide dismutase (SOD) was determined in liver homogenates after perfusion and after the preservation period. The results were compared with pure HTK, Ringer's and reference University of Wisconsin (UW) solutions. RESULTS: 30 min of perfusion and 12 h of cold preservation (CIT) in the Ringer's solution markedly increased GPx, SOD, and GR activities in liver homogenates compared with the activity using other fluids. After 12-h CIT the activities of GR, GPx and SOD were significantly higher in cys-modified HTK solution than the control HTK solution. They were comparable to the values recorded for the UW group. CONCLUSIONS: Addition of cys to the HTK solution positively influenced the total pool of free radical scavengers in a liver undergoing 12-hour ischemia in the simple hypothermia, which was reflected in the elevated redox enzyme activity possibly due to cys participation in GSH synthesis.

Adrenaline and dopamine in porcine livers after cold preservation with University of Wisconsin histidine-tryptophan-ketoglutarate, prolactin-modified histidine-tryptophan-ketoglutarate solutions.

INTRODUCTION: Hepatic ischemia-reperfusion injury remains a significant factor influencing early liver graft function. The aim of this study was to assess the impact on hepatic ischemia as reflected by catecholamine concentrations of different methods of organ preservation. MATERIALS AND METHODS: Catecholamine levels were measured in 24 (n=6/group) pig livers, which underwent 30-minute warm ischemia followed by 30-minute perfusion and subsequent cold storage for 12 hours. For perfusion and preservation, we used University of Wisconsin (UW), histidine-tryptophan-ketoglutarate (HTK), HTK-modified with prolactin (PRL) or Ringer's solutions. Dopamine (DO) and adrenaline (ADR) concentrations in liver venous effluents were assayed using a radioimmunological method after 30 minutes of perfusion and following 12 hours of preservation. RESULTS: DO and ADR levels were higher after 12 hours preservation compared to 30 minutes of perfusion. HTK produced an increase of over 100%. Addition of PRL (20 IU/L) did not affect DO and ADR levels after 30 minutes of perfusion, but significantly decreased their concentrations at 12 hours of preservation. After UW perfusion and preservation, we observed a 10% increase in catecholamine levels as compared with postperfusion values. Preservation with Ringer's solution demonstrated significantly higher DO and ADR levels compared with other solutions. CONCLUSION: Catecholamines are present in the liver after 30 minute of perfusion and 12 hours of cold storage. The increased levels after 12 hours of preservation may be due to their release from intracellular spaces (as a controlled process or as a result of necrosis). It may play a crucial role in reperfusion injury, which, in turn, may explain the mechanism of no-reflow phenomenon.

Evaluation of apoptosis in the liver preserved by simple hypothermia using histidine-tryptophan-ketoglutarate and prolactin-modified histidine-tryptophan-ketoglutarate solution.

INTRODUCTION: Organ ischemia is accompanied by cell death due to apoptosis. It occurs together with necrosis, which has more unfavorable consequences due to the release of cytokines that activate the inflammatory response cascade. The aim of this study was to assess the degree of apoptosis in porcine livers preserved by simple hypothermia for 12 hours using standard solutions (University of Wisconsin [UW] and histidine-tryptophan-glutarate [HTK]), and to evaluate the effect of prolactin (PRL) addition to the HTK solution. MATERIALS AND METHODS: The study was performed on the livers of Great White breed pigs, after inducing 30 minutes of warm ischemia (WIT30), followed by 30 minutes of perfusion-cooling to 4°C, and 12 hours of preservation. Livers were evaluated after preservation in Ringer's solution (control); UW (control reference fluid); HTK and HTK modified by the addition of prolactin (20 UI/L. Apoptosis was assessed in liver sections by the TdT-mediated dUTP nick-end labeling method after 12-hour preservation. We adopted a prevalence scale ranging from 0 to 3+, depending on the number of observed nuclei and apoptotic bodies (AB). RESULTS: Preservation in Ringer's solution yielded AB distribution at the 1+ level, with a lack of characteristic localization resulting from necrotic lesions. Analysis of the livers preserved in the UW solution showed high, 3+ level of AB presence. For the tested HTK solution, the observed ABs localization value was 3+, whereas in the PRL-modified group it was also 3+, but with a tendency to move from zone II to cluster III, which is important for liver metabolic functions. CONCLUSIONS: PRL improved the preservation properties of HTK for porcine livers by maintaining a high apoptosis level. It may stabilize cell membranes thus reducing the oncotic necrosis, promoting increased apoptosis during simple hypothermia.

The effect of HTK solution modification by addition of prolactin on biochemical indices reflecting ischaemic damage to porcine kidney.

INTRODUCTION: The aim of our study was to evaluate the impact of perfusion with HTK solution, modified by the addition of prolactin (PRI), on selected biochemical parameters of porcine renal damage within 24 and 48 hours after the onset of cold ischemia time. METHODS: Each study group consisted of 10 adult pigs. During harvesting the kidneys were rinsed with Ringer's solution (group 1), HTK (group 2), and HTK+PRL in a dose of 0.2 mg/dL, 0.02 mg/dL, and 0.01 mg/dL in groups 3, 4 and 5, respectively. The levels of lactate dehydrogenase, asparagine (AST) and alanine aminotransferases, lactates, total protein, potassium and calcium were determined in the perfusate. After 24 and 48 hours the rinsing procedure and the abovementioned tests were repeated. RESULTS: After 24 hours of storage, in 4 groups, significantly lower levels of LDH (U/L) were recorded compared with HTK solution alone, namely 235 ± 93 versus 271 ± 125 (perfusion minute, 0), and 55 ± 21 versus 125 ± 94 (30th minute). Similar behavior pattern was presented by AST (U/L) and potassium (mmol/L), and the results were 31 ± 8 versus 35 ± 12 and 16 ± 10 versus 29 ± 14, and 12 ± 3 versus 16 ± 3 and 10 ± 1 versus 13 ± 1, respectively. The changes described above were not observed in the 48th hour of reperfusion. CONCLUSION: Our study results indicate the possibility of cytoprotective action of PRL after adding it to the fluid perfusing kidneys during cold ischemia. This effect, observed after 24 hours of storage, was to a considerable extent dose dependent. In our experiment the effect was pronounced only at 0.02 mg/dL supply of PRL.

Effect of prolactin on release of selected enzymes from the isolated rabbit liver.

This report analyzes the effect of prolactin (PRL) on ALT and AST release from the rabbit liver into the preservation solution. Dissected and perfused livers were stored for 24 hours in Ringer's solution without (control group) or with PRL (experimental group). During the organ preservation, sample of the solution were obtained at 1, 8, 12, 16, 18, and 24 hours. It was found that PRL added to Ringer's solution significantly decreased the quantity and rate of released ALT (P < .081) and AST (P < .029) from the preserved liver. ALT was released 2.51 times more slowly (kappa = -0.03329 [h(-1)]) and AST 3.43 times more slowly (kappa = -0.08356 [h(-1)]) into Ringer's solution with PRL. The experimental group showed maintenance of the value of the de Ritis index at a stable level between 2.0-3.0. In conclusion, PRL added to a preservation solution significantly decreased the quantity and slowed the release rate of ALT and AST aminotransferases from the preserved rabbit liver, implying that this hormone has hepatoprotective properties.

Influence of salt form and concentration on the absorption of magnesium in rat small intestine.

The influence of magnesium concentration and salt form on the absorption of this element in the rat small intestine was investigated. The following magnesium salts were studied: gluconate, fumarate, and chloride. At 1 and 5 mM concentrations absorption was most efficient from gluconate whereas at 10 mM absorption from fumrate was more efficient. Mg2+ absorption half-life (t50%) varied with salt and concentration. The Mg2+ absorption half-life for magnesium gluconate at 10 mM concentration was 42 times as long as at 1 mM concentration. The biggest area under the curve, which characterizes substance bioavailability, was observed for each of the investigated salts at 5 mM. Therefore, we may conclude that magnesium administration at 5 mM concentration would be optimal.

Isolation and properties of glycosylated pig prolactin (G-PRL).

Isolation and properties of glycosylated pig prolactin (G-PRL)--Crude prolacting was received via extraction from lyophilized hypophyses with acidic 70% acetone, and then by protein precipitation via increasing acetone concentration in the extract to 92%. Received precipitate was dissolved in 0.1 M acetic acid and prolactin was precipitated in the isoelectric point at the pH = 4.97. Prolactin precipitate was dissolved in phosphate buffer pH = 7.50 and adsorbed on the DEAE-Sephadex column, and then eluated with linear gradient at NaCl concentration range 0.00-0.40 M. Prolactin with molecular mass 24.0 kD was eluated at NaCl concentration 0.19-0.25 M. Using gel filtration method on Sephadex G-100 glycosylated prolactin was divided into 2 fractions with molecular mass equal--55.8 and 17.4 kD. Both 24.0 kD--prolactin and its glycosylated form were characterized by high biological activity. Glycosylated prolactin contains among others mannose and fucose.

The influence of prolactin on the chosen biochemical parameters of the rabbit liver in ischemia.

An experimental model, based on Pringle's scheme of acute warm hepatic ischemia in normothermia was employed in order to study the hepatoprotective properties of prolactin (PRL). In the proposed model one liver lobe was maintained in the portal circulation and the remaining lobes were perfused with HTK solution for 2 hours. The experiment was carried out on female rabbits of the Chinchilla race. In the control group (n= 10) the liver was perfused with HTK solution. In the examined group (n=10), 3 microg of PRL per g of liver per hour was added to HTK solution. Additionally, the animals in the PRL-treated group were intravenously administered a dose of 600 microg of PRL / kg body weight. 1 h before the surgical treatment. The activities of alanine aminotransferase (ALT), alkaline phosphatase (ALP). gamma-glutamyl transferase (GGT) and the lactate concentration were determined in the eluate obtained from the perfused part of the liver. It was found that administration of prolactin during 2 h of perfusion led to a significant decrease of ALT, ALP and lactate concentrations in the eluate. In addition, increase of calcium concentration in the liver was significantly lower with the prolactin group. The observed results let us to draw the conclusion that administration of PRL shows signs of protective effects on hepatocytes in normothermic acute ischemia.

Calcium concentration at rat females with osteoporosis after applying calcium fumarate.

The dynamics of total calcium concentration in blood of rat females with osteoporosis caused experimentally after applying it in the form of fumarate was determined. The fumarate was applied in just one dose by the means of stomach tube at the dose of teoporoz_ 4.28 mg of calcium/100 g of body mass. The total calcium concentration in blood was determined: 0; 1; 2; 3; 5 i 7 h after application. It was observed that one hour after application calcium concentration in control group increased by 19.3%, and in the group of animals after ovariectomy it decreased by 6.7% (P < 0.001). After 2 h calcium concentration in both groups returned to its initial state, and after 3 hours three next decrease in relation to initial time by 10% occurred in the control group and by 4% in the group after ovariectomy. Between 4 h and 7 h after administration calcium concentration in both groups of animals was even and it was maintaining at the constant level in the range 2.248-2.172 mM/l.