Biopolymers and cell. 1995; 11 (2): 76 - 81

NITRIC OXIDE PRODUCTION BY THE REGENERATING RAT LIVER

M. Yu. Obolenskaya, A. F. Vanin, P. I. Mordvintcev, K. Decker

Nitric oxide (NO) production in the regenerating liver was estimated from the intensity of the electron paramagnetic resonance signal of the mononitrosyl complexes of iron and diethylthiocarbamate (DETC). Preformed complexes of intracellular non-heme Fe2+ and added DETC served as a trap for endogeneously produced NO. The data revealed dynamic changes of NO production temporally connected with the time periodicity of the liver regeneration. The first increase of NO production occurred ca. 1 h after partial hepatectomy (PHE) coinciding with the rapid response of the liver to injury. The second more pronounced production of NO was observed about 6 h after PHE, when the hepa-tocytes entered the first cell cycle, and originated mainly from them. The following minimum of NO synthesis coincided with the maximal rate of DNA synthesis. The third gradual rise of NO production was seen at the end of the investigated period, covering G2+M phases and the transit from the first to the second cell cycle of the hepatocytes and the entrance of nonparenchymal cells into the proliferation.