RESPIRATION AND ADENINE-NUCLEOTIDES OF BALTIC LAMPREY (LAMPETRA-FLUVIATILIS L.) HEPATOCYTES DURING SPAWNING MIGRATION

Seasonal variations of lamprey hepatocyte endogenous respiration durin g spawning migration (November-May), when the animals are starving, we re determined. In winter, the respiration is decreased 2.5-3 times as compared with the respiration of early migrants in Autumn and markedly (about twice) increased again in Spring (April). The reasons for such regulation are discussed. The respiration responsible for ATP synthes is and proton leak and non-mitochondrial respiration in hepatocytes we re determined in every season. The content of adenine nucleotides in h epatocytes of the autumn migrants was close to that of mammals. Howeve r, ATP concentration in Winter decreased markedly (ten times in indivi dual animals). Isolation of viable cells at this period is possible on ly in the medium with pH 6.5. In Spring, the level of adenine nucleoti des again reached the Autumn value. Weight characteristics and protein content of lamprey hepatocytes are about ten times lower than those o f the mammalian ones. The mass of lamprey hepatocytes decreased by 30- 40% at the period from early Spring to the spawn in May, most likely t his decrease being due to the lipid expenditure. (C) 1998 Elsevier Sci ence Inc. All rights reserved.