Effects of extracellular nucleotides and their hydrolysis products on volume regulatory decrease of hepatocytes from trout (Oncorhynchus mykiss)

PAFUNDO, D E; MUT, P; PÉREZ RECALDE, M; GONZÁLEZ-LEBRERO, R. M; FACHINO, V; KRUMSCHNABEL, G.; P. J. SCHWARZBAUM

AMERICAN JOURNAL OF PHYSIOLOGY-REGULATORY, INTEGRATIVE AND COMPARATIVE PHYSIOLOGY

AMER PHYSIOLOGICAL SOC

Año: 2004 vol. 287 p. 833 - 843

0363-6119

Effects of extracellular nucleotides and their hydrolysis products on regulatory volume decrease of trout hepatocytes In trout hepatocytes, hypotonic swelling is followed by a compensatory shrinkage called regulatory volume decrease (RVD). It has been postulated that extracellular ATP and other nucleotides may interact with type 2 receptors (P2) to modulate this response. In addition, specific ectoenzymes hydrolyze ATP sequentially down to adenosine, which may bind to type 1 receptors (P1) and also influence RVD. Accordingly, in this study, we assessed the role of extracellular nucleoside 5´-tri- and diphosphates and of adenosine on RVD of trout hepatocytes. The extent of RVD after 40 min of maximum swelling was denoted as RVD40, whereas the initial rate of RVD was called vRVD. In the presence of hypotonic medium (60% of isotonic), hepatocytes swelled 1.6 times followed by vRVD of 1.7 min?1 and RVD40 of 60.2%. ATP, UTP, UDP, or ATP S (P2 agonists; 5 μM) increased vRVD 1.5-2 times, whereas no changes were observed