The binding of insulin (IMS) and glucagon (GL) on isolated rat hepatocytes during the process of liver regeneration after partial hepatectomy was determined. Adult male rats were subjected to 65-70 % partial hepatectomy, control animals were sham-operated. The binding of radioiodine labelled IMS and GL to isolated hepatocytes was determined 1, 2, 3 and 5 days after the surgery. The plasma levels of IMS and glucose and microviscosity of liver plasma membranes were also measured. The decrease of IMS receptor binding capacity was found 1, 2, and 3 days after operation. Mo differences in sham and partially hepatectomized groups in IMS binding were noted 5 days after operation. A single insulin injection during the process of regeneration did not affect these changes of IMS binding to hepatocytes. The increase of GL binding was observed on the third day after partial hepatectomy, however, on the 5th day no changes of GL binding to its receptors were noted. The plasma insulin and glucose levels were similar in both hepatectomized and sham-operated rats. The increase of plasma membrane microviscosity of hepatocytes during the process of liver regeneration and a negative correlation between IMS binding and membrane microviscosity were found. These results demonstrated significant changes in binding parameters of both IMS and GL receptors in hepatocytes during liver regeneration induced by partial hepatectomy.
Decades of liver regeneration studies still left the termination phase least elucidated. However regeneration ending mechanisms are clinicaly relevant. We aimed to analyse the timing and transcriptional control of the latest phase of liver regeneration, both controversial. Male Wistar rats were subjected to 2/3 partial hepatectomy with recovery lasting from 1 to 14 days. Time-series microarray data were assessed by innovative combination of hierarchical clustering and principal component analysis and validated by real-time RT-PCR. Hierarchical clustering and principal component analysis in agreement distinguished three temporal phases of liver regeneration. We found 359 genes specifically altered during late phase regeneration. Gene enrichment analysis and manual review of microarray data suggested five pathways worth further study: PPAR signalling pathway; lipid metabolism; complement, coagulation and fibrinolytic cascades; ECM remodelling and xenobiotic biotransformation. Microarray findings pertinent for termination phase were substantiated by real-time RT-PCR. In conclusion, transcriptional profiling mapped late phase of liver regeneration beyond 5th day of recovery and revealed 5 pathways specifically acting at this time. Inclusion of longer post-surgery intervals brought improved coverage of regeneration time dynamics and is advisable for further works. Investigation into the workings of suggested pathways might prove helpful in preventing and managing liver tumours., D. Rychtrmoc, ... [et al.]., and Obsahuje seznam literatury