M. Kitakaze et al., VESNARINONE INHIBITS ADENOSINE UPTAKE IN ENDOTHELIAL-CELLS, SMOOTH-MUSCLE CELLS AND MYOCYTES, AND MEDIATES CYTOPROTECTION, Journal of Molecular and Cellular Cardiology, 29(12), 1997, pp. 3413-3417
Vesnarinone is a novel synthetic inotropic agent. Recently, it has bee
n reported that vesnarinone inhibits adenosine uptake in the B-lymphoc
ytoid cell line. Since extracellular adenosine is cardioprotective, we
examined whether vesnarinone inhibits adenosine uptake in cells const
ituting the cardiovascular system. 1 mu Ci of [H-3]adenosine was added
to cells of the myocyte cell line (C2C12), human coronary smooth musc
le cell line (HCASMC), human and bovine coronary endothelial cell line
s (HCAEC and BCAEC), bovine arterial endothelial cell line (BAEC), and
human umbilical venous endothelial cell line (HUVEC). After 10s - 5 m
in, cells were separated from free [H-3]adenosine, and the radioactivi
ty was measured. When 0.1-100 mu M of vesnarinone was added to each ce
ll line, the uptake of adenosine was inhibited dose-dependently {% inh
ibition of [H-3]adenosine uptake at 10 and 30 mu M of vesnarinone: 14
and 33% (C2C12), 47 and 72% (HCASMC), 37 and 58% (HCAEC), 42 and 68% (
BCAEC), 19 and 68% (BAEC), 29 and 59% (HUVEC)). The cellular viability
of HCAEC exposed to 60 min of hypoxia and 60min of reoxygenation incr
eased from 34 +/- 5 to 67 +/- 6% (Trypan blue exclusion test) and 23 /- 5 to 78 +/- 6% (LDH release), which was completely blunted by 8-sul
fophenyltheophylline, an adenosine receptor antagonist, and was partia
lly blunted by alpha,beta-methyleneadenosine 5'-diphosphate, an inhibi
tor of ecto-5'-nucleotidase. We also found that vesnarinone is cytopro
tective against hypoxia and reoxygenation in C2C12 and HCASMC. We conc
lude that vesnarinone inhibits the uptake of adenosine in cardiovascul
ar cells, which contributes to cytoprotection. (C) 1997 Academic Press
Limited.