['This study investigated methods of increasing the effectiveness of preservation solutions. Recently, it has been reported that solution effectiveness can be improved by the addition of prolactin (PRL). This study determines the effect of prolactin (PRL) on the amount and release rate of alanine aminotransferase (ALAT) and aspartate aminotransferase (AST) from liver during its 24-hour preservation period.', 'Isolated porcine liver was kept in the HTK (histidine-tryptophan-ketoglutaric acid) solution with and without PRL. Once infusion and the 24-hour preservation period had been finished, samples of the preservation solution were taken and the amounts of released indicator enzymes were determined.', 'Aminotransferases were released from hepatocytes to the preservation solution at various rates. ALT was released much faster into the solution without PRL (k=-0.1230 [U/l/h-1]) and slower with PRL (k=-0.0895 [U/l/h-1]). The enzyme was released into the solution with PRL at a 27% slower rate. Similar results were obtained when the release rate of AST was analyzed. AST was more quickly released into the solution without PRL (k=-0.0642 [U/l/h-1]), and more slowly with PRL (k=-0.0205 [U/l/h-1]). The enzyme was released into the PRL-containing solution at a 68% slower rate.'] Does prolactin ( PRL ) reduce the release of transaminases from the isolated pig liver?