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.

Differential action of two prolactin isoforms on ischemia and re-perfusion-induced arrhythmias in rats in vivo.

BACKGROUND: The different influences of one of the PRL isoforms (PRL I) on the cardiovascular system have been described in the past. AIM: Our goal was to establish an appropriate iv dose of 2 PRL isoforms (PRL I and PRL II) in intact rats. After establishing this dose, PRL I (0.01 mg/kg) or PRL II (0.001 mg/kg) was administered in bolus 10 min before left anterior descending coronary artery occlusion (7 min) followed by re-perfusion (15 min). We then aimed to study and compare the effects of these isoforms on ischemia- and re-perfusion-induced arrhythmias in the ischemia and re-perfusion-induced arrhythmias model in rats. MATERIALS AND METHODS: Mortality index, ventricular fibrillation and tachycardia (VF, VT) incidence and duration, systolic, diastolic, and mean arterial blood pressure, heart rate and myocardial index of oxygen consumption [pressure rate product (PRP)] were measured and calculated. RESULTS: Both PRL isoforms reduced animal mortality (from 50 to 18.75 and 25%, respectively). PRL II significantly reduced VF incidence (to 25%) as well as VT duration (18.21 ± 3.09) and these effects were markedly different from PRL I and from the control group (p<0.05). Both PRL reduced PRP in the recovery phase (p<0.05). CONCLUSIONS: We proved that supraphysiological doses of PRL isoforms administered in bolus could protect against sudden cardiac death as well as severe arrhythmias episodes during re-perfusion. Because of PRL's positive influence on the cardiovascular system and as an endogenous, well-tolerated substance, it might be of potential clinical use.

Insulin availability from mucoadhesive tablets.

The widespread implementation of peptides as drugs encounters numerous obstacles, the main being invasive and inconvenient parenteral administration. Oral transmucosal administration is one of the possible alternatives, valuable for its noninvasiveness and easy accessibility. The aim of our study was to determine the implementation possibilities of mucoadhesive tablets prepared on a methylcellulose and sodium alginate basis with an addition of absorption-modifying hyaluronic acid, as carriers for peptides destined for oral transmucosal administration. Two series of 50 mg tablets containing 5mg of insulin were prepared for the study. The first series contained methylcellulose, hyaluronic acid and mannitol, while the second series' formulation included sodium alginate, hyaluronic acid and mannitol. Carried out study confirmed that insulin administration in the form of mucoadhesive tablets lowers blood glucose levels in rabbits. Better effects were reached in vivo in the case of MC-based tablets, for which stronger and longer glycemia lowering was achieved.

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.

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.

Caspase-3 Expression and ALT, AST, and GGT Activity After 24 Hours of Porcine Liver Cold Storage, Depending on the Type of Transgenesis.

BACKGROUND: Because of an insufficient number of human organs for transplantation, xenotransplantation may become an effective alternative. We aimed to analyze if the type of transgenesis has an influence on the hepatic caspase-3 expression, the enzyme that executes apoptosis as well as ALT, AST, and GGT activity after 24 hours of cold storage. METHODS: The experiment was carried out on the 24 livers of Polish White Landrace pigs carrying human α1,2-fucosyltransferase and/or α-galactosidase (GAL) genes and livers without this genetic modification (control). Livers were perfused, stored for 24 hours in solution, and subsequently re-flushed. Hepatic concentration of the caspase-3 protein and its mRNA expression were measured just after the animal was killed as well as after 30 minutes of perfusion and after 24 hours of cold storage followed by 30 minutes of reperfusion. Caspase-3 mRNA level was detected with the RT-PCR method. Protein concentration (capsase-3 active and inactive) was assessed with the Western blotting technique. Kinetic methods were applied for the analysis of the ALT, AST, and GGT activity. RESULTS: The highest increase of the ALT activity after cold storage was observed in the group with GAL transgenesis, whereas the GGT activity was highest in the unmodified livers. There was no difference in the caspase-3 expression and AST activity after cold storage as compared with the respective initial results (P = .57 and P = .97, respectively). CONCLUSIONS: It appears that transgenesis does not aggravate ischemic injury of the liver.

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.

Concentration of Tumor Necrosis Factor-α and Interleukin-1ß in Isolated Porcine Liver Depending on Type of Transgenesis.

BACKGROUND: Transgenic animals may serve as organ donors in human organ transplantation. However, the number of the studies addressing all doubts related to this issue is currently insufficient for the clinical application of this approach. The aim of this study was to analyze the hepatic tumor necrosis factor-α (TNF-α) and interleukin-1ß (IL-1ß) synthesis during a 24-hour cold preservation of the transgenic pig liver, depending on the type of transgenesis. MATERIALS AND METHODS: The study was carried out on wild-type and transgenic pig livers with transferred human α1,2-fucosyltransferase (FUT) and/or α-galactosidase (GAL) gene (four groups; n = 6). Harvested livers were perfused for 30 minutes and stored for 24 hours in Biolasol (Biochefa) solution at 4°C with a subsequent 30-minute reperfusion (reflush). TNF-α and IL-1ß concentrations were analyzed with an enzyme-linked immunosorbent assay. Perfusates were collected during the initial perfusion as well as after 24 hours of preservation and during the reperfusion. Tissue samples were harvested just after animal sacrifice, and after organ perfusion and reperfusion. RESULTS: A decrease in TNF-α concentration in homogenates was noted after both perfusion and reperfusion in all experimental groups. In contrast, there was a significant decrease in IL-1ß concentration in the group with combined human FUT and GAL transgenes. Concurrently, increases in TNF-α and IL-1ß concentrations were observed in the reperfusion perfusates in all groups. CONCLUSION: This study shows that IL-1ß is synthesized in the ischemic livers of the transgenic animals with both human α1,2-fucosyltransferase and α-galactosidase transgenes. Further analysis is required to determine the importance of this observation.

Behavioural effects of luteinizing hormone-releasing hormone (LHRH) in rats.

Behavioural effects of intracerebroventricularly-injected (icv) LHRH were studied in female rats. Locomotor and exploratory activities as well as irritability were determined. A pronounced inhibitory effect of 10 micrograms doses of LHRH was found. At 100 micrograms doses of LHRH, barrel behaviour was observed. We conclude that LHRH can modify the activity of central serotonergic receptors in rats.

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.

Distribution of prolactin in selected rat organs and tissues.

A single dose of 25 microg prolactin (PRL)/kg of rat body weight was administered to rats subcutaneously. At 1, 2, 3, 4 and 5 h after the injection, selected organs and tissues were taken for analysis. It was found that 1 h after administration, the highest amount of PRL accumulated in the milk (lactiferous) gland, the blood, the ovaries, the pituitary and the liver. Over time, the prolactin content in the selected organs and tissues decreased. PRL is selectively captured by the milk gland, the pituitary, the ovaries, the liver and the heart. Based on the value of the organ or tissue capacity index for PRL, the following order was established for the organs and tissues to which the hormone binds: milk gland > blood > pituitary > ovaries > lungs > liver > cranial bone > spleen > heart > kidneys > muscular tissue > adrenals > adipose tissue > brain.

Bioavailability of dalarelin--a superactive GnRH analogue--in rats.

125I-marked dalarelin (a modified analogue of GnRH) or GnRH (gonadotropin-releasing hormone) were administered to the tested rats in single doses of 127 ng/kg by subcutaneous injections. Dalarelin and GnRH were absorbed from the injected doses in 0.64 and 0.49%, respectively. Only one remarkable maximal concentration of these hormones was noticed in rats' blood 30 min after the administration. Dalarelin maximal concentration was 261.5 pg/cm3 and was 93.43% higher than the maximal concentration of GnRH. Dalarelin bioavailability was 1651.89 pg/cm3, whereas GnRH bioavailability was 718 pg/cm3 h. The bioavailability level of dalarelin was 230% compared with that for GnRH, which was accepted as a pattern of bioavailability.

Uptake of prolactin and tyroliberin by the heart.

The aim of this study was to observe the specificity of prolactin and tyroliberin uptake and thus to determine their affinity for the heart ventricles and atria. Comparison of the uptake of the examined substances revealed that more of these hormones reached the atria than the ventricles. The contents of prolactin and tyroliberin in the atria were statistically significant compared with 125J. The results observed provide evidence for nonuniform prolactin uptake by the heart.

Distribution of 125J-labeled leucopyrokinin (LPK) in rats.

The distribution in parts of the brain and internal organs of 125J-labeled leucopyrokinin (LPK), an insect myotropic peptide injected into the lateral brain ventricle was determined in rats. A high accumulation of this peptide in adrenals and in the hypothalamus and hippocampus of the brain was found. A lesser but significant LPK accumulation in other internal organs and parts of the brain was also observed. The significance of this effect for the biological activity of LPK in rats is discussed.

Pharmacokinetics and distribution of selenium in blood and organs of rats.

The dynamics of selenium concentration changes in blood, organs and tissues of rats after a single intragastric administration of selenium yeast and sodium selenite was determined. The course of selenium concentration changes in blood was described, the pharmacokinetic parameters were estimated according to the trivalent equation of dicompartment model and the selenium content in liver, kidneys, small intestine, spleen, heart, brain, stomach, testicles and prostate was determined 48 h after the administration of selenium preparations.

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.

The effect of the chemical composition of albumin-containing microcapsules upon their properties.

The effect of the composition of the coating (gelatine, sodium alginate, acetic acid) covering the biodegradable microcapsules upon their efficiency as well as upon albumin incorporation percentage value, were determined by the method of the 3 x 3 Latin squares. Selected physical and chemical properties of the microcapsules as well as the rate of albumin release from the microcapsules were investigated. Microcapsules suitable for parenteral administration were prepared using the method of a complex coacervation with the model substance: human albumin. None of the selected components of the coating was found to have any significant effect upon the efficiency of the microcapsules. However, it was established that the albumin incorporation effect was significantly influenced by gelatine concentration in the composition of the component. Based on the attained results, the composition of the biodegradable capsules was determined: 5% gelatine; 3% sodium alginate; and 25% acetic acid. Using the gelatin-sodium alginate system, microcapsules containing albumin with a prolonged release time, suitable for parenteral administration, were obtained.

Initial studies on the administration route of prolactin.

The influence of administration route of prolactin on its biological availability in rats was determined. Prolactin was administered intraperitoneally, intramuscularly and intranasally (intranasal inhalation) in single doses of 2.5 mg/kg body weight. Within 5 hours after the administration, there were noticed evident differences in prolactin concentrations in blood dependening on the route of administration. The maximal prolactin concentration after its intraperitoneal administration was 1.5 times as high as the maximal concentration observed for intramuscular or intranasal administration. The area under the curves: concentration: intraperitoneal administration time and concentration: intramuscular administration time was 132.99 ng/cm3/h and 136.28 ng/cm3/h, respetively. The area under the curve (AUC0-&) for the intranasal administration of prolactin was not much different than for the intraperitoneal and intramuscular ones, and was 111.30 ng/cm3/h.