ANP protects against reoxygenation-induced hypercontracture in adult cardiomyocytes.
It was investigated whether atrial natriuretic peptide (ANP) or the related peptide urodilatin can be used for protecting cardiomyocytes against reoxygenation-induced hypercontracture. Isolated ventricular cardiomyocytes (from adult rats) were used as the experimental model. When the cells were submitted to substrate-free anoxia (135 min) and subsequent reoxygenation (30 min), the onset of reoxygenation provoked their hypercontracture. It was studied whether the temporary presence of ANP or urodilatin (1 nM to 1 microM) or 8-bromo-guanosine 3',5'-cyclic monophosphate (8-BrcGMP; 1 microM to 1 mM) during the last 15 min of anoxia and the first 15 min of reoxygenation prevented hypercontracture. It was found that ANP (1 microM) prevented hypercontracture in 82 +/- 8% (SD), urodilatin (1 microM) in 80 +/- 9%, and 8-BrcGMP (1 mM) in 72 +/- 10% of the cells (n = 40 cells). When ANP (1 microM) was added during the last 15 min of anoxia and the first 15 min of reoxygenation, the cellular concentration of cGMP increased from 0.41 +/- 0.04 to 2.80 +/- 0.81 pmol/mg protein (n = 6 cultures). The results show that the reoxygenation-induced hypercontracture in cardiomyocytes can be attenuated by the temporary presence of the stimulators of particulate guanylate cyclase, ANP or urodilatin.
Hempel
A
A
Physiologisches Institut, Justus-Liebig-Universität, Giessen, Germany.
Friedrich
M
M
Schlüter
K D
KD
Forssmann
W G
WG
Kuhn
M
M
Piper
H M
HM
D000332:Aerobiosis; D000704:Analysis of Variance; D000818:Animals; D009320:Atrial Natriuretic Factor / Q000494:pharmacology*; D015687:Cell Hypoxia / Q000187:drug effects / Q000502:physiology*; D002478:Cells, Cultured; D006152:Cyclic GMP / Q000031:analogs & derivatives / Q000494:pharmacology; D004232:Diuretics / Q000494:pharmacology; D004734:Energy Metabolism / Q000187:drug effects; D006321:Heart / Q000187:drug effects / Q000502:physiology*; D006352:Heart Ventricles; D007700:Kinetics; D008297:Male; D009200:Myocardial Contraction / Q000187:drug effects* / Q000502:physiology; D009206:Myocardium / Q000378:metabolism; D010100:Oxygen / Q000494:pharmacology; D010446:Peptide Fragments / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar
D004232:Diuretics; D010446:Peptide Fragments; C016276:8-bromocyclic GMP; C056452:Ularitide; D009320:Atrial Natriuretic Factor; D006152:Cyclic GMP; D010100:Oxygen