Hepatoprotective Effect of Prolactin and Cysteine Contained in Perfusion and Preservation Solutions on Porcine Liver Stored in Simple Hypothermia

Pharmacological Benefits and Risk of Using Hormones in Organ Perfusion and Preservation Solutions in the Aspect of Minimizing Hepatic Ischemia-Reperfusion Injury during Storage

For several years, research has been carried out on the effectiveness of solutions for perfusion and preservation of organs, including the liver. There is a search for an optimal pharmacological composition of these solutions, allowing to preserve or improve vital functions of the organ for as long as possible until it is transplanted into a recipient. Hormones due to their properties, often resulting from their pleiotropic effects, may be a valuable component for optimizing the composition of liver perfusion and preservation solutions. The paper presents the current state of knowledge on liver perfusion and preservation solutions modified with hormones. It also shows the characteristics of the hormones evaluated, taking into account their physiological functions in the body.

The Effect of Modified Biolasol Solution on the Efficacy of Storing Isolated Porcine Kidneys

Biolasol is a newly developed solution for storing the liver, pancreas, kidneys, and heart by simple hypothermia. It exhibits high efficacy in maintaining structural and functional integrity of the graft prior to its transplantation. The solution was modified by the addition of ascorbic acid (0.088g/l) and ascorbic acid with prolactin (1 μg/l PRL + 0.088g/l vitamin C). The effectiveness of the obtained solutions in the protection of nephrons of isolated porcine kidneys was assessed based on the analysis of the activity of ALT (alanine aminotransferase), AST (aspartate aminotransferase), and LDH (lactate dehydrogenase) as well as lactate concentration determined in perfundates collected after 2 h (0' and 30' preservation) and 48 h (0' and 30' preservation) of graft storage. It has been found that the synergistic action of Biolasol components determines the integrity and stability of cell membranes, which in turn affects the proper functioning of the organ after transplantation. The addition of ascorbic acid and prolactin to Biolasol affects the maintenance of the normal cytoskeleton of the stored graft.

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 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.

Liver protection strategies in liver transplantation

BACKGROUND

Liver transplantation is the therapy of choice for patients with end-stage liver diseases. However, the gap between the low availability of organs and high demand is continuously increasing. Innovative strategies for organ protection are necessary to expand donor pool and to achieve better outcomes for liver transplantation. The present review analyzed and compared various strategies of liver protection.

DATA SOURCES

Databases such as PubMed, Embase and Ovid were searched for the literature related to donor liver protection strategies using following key words: "ischemia reperfusion injury", "graft preservation", "liver transplantation", "machine perfusion" and "conditioning". Of the 146 studies identified, only those with cutting edge strategies were analyzed.

RESULTS

A variety of therapeutic approaches were proposed to alleviate graft ischemia/reperfusion injury, which included static cold storage, machine perfusion (hypothermic, normothermic and subnormothermic), manual conditioning (pre, post and remote), and pharmacological conditioning. Evidences from animal experiments and clinical trials suggested that all these strategies could potentially protect liver graft; however, their clinical applications are limited partially due to their own disadvantages.

CONCLUSIONS

There are a plenty of methods suggested to decrease the degree of donor liver transplantation-related injury. However, none of these approaches is perfect in clinical practice. More translational researches (molecular and clinical studies) are needed to improve the techniques in liver graft protection.

Influence of trace elements on stabilization of aqueous solutions of ascorbic acid

Together with vitamin C, zinc, selenium, manganese, and magnesium play a vital role in the preservation of organs scheduled for transplantation. In the present study, it is shown that addition of 1 mg/l of these elements influences the stability of 0.3 mM ascorbic acid solutions. The solution's stability was estimated using an accelerated stability test. The concentration of vitamin C was measured using a validated spectrophotometric method, which uses the reduction of 2,6-dichlorophenoloindophenol by ascorbic acid. Elevated temperatures, the factor accelerating substances' decomposition reaction rate, were used in the tests. The research was conducted at two temperatures at intervals of 10 °C: 80 ± 0.1 and 90 ± 0.1 °C. It was stated that the studied substances' decomposition occurred in accordance with the equation for first-order reactions. The function of the logarithmic concentration (log%C) over time was revealed to be rectilinear. This dependence was used to determine the kinetics of decomposition reaction rate parameters. The stabilization of vitamin C solutions was measured as the time in which 10 % of the substance decomposed at 20 and 0 °C. Addition of Se(IV) or Mg(II) ions significantly increase the stability of ascorbic acid solution (∼34 and ∼16 %, respectively), but Zn(II) causes a significant decrease in stability by ∼23 %. Addition of Mn(II) has no significant influence on vitamin C stability.