Regulation of membrane phospholipid metabolism in heart cell culture.
We have isolated, from newborn rats, heart cultures enriched in contractile muscle cells (M) and cultures of fibroblast-like cells (F). M cultures respond to simulated ischemia by an arrest of beating activity, by a decrease in beta oxydation rate, ATP and phosphocreatine content and by a loss of membrane phospholipids associated with neutral lipids accumulation. F cells in contrast do not respond to oxygen deprivation. Firstly, we observed that cocultures of M and F cells respond to oxygen deprivation by an arrest of beating activity and a decrease in cellular ATP content, but failed to exhibit any significant loss of membrane phospholipids. Secondly, we demonstrated that culture medium conditioned by F cells is able to inhibit the reaction of M cells to simulated ischemia thus suggesting that fibroblasts produce a diffusible factor able to block phospholipase activation. Heat treatment and trypsinisation failed to abolish this activity, indicating that the phospholipase inhibitory factor is probably not a polypeptide.
Freyss-Beguin
M M
MM
Laboratoire de Pharmacologie, URA CNRS 1482, Faculté de Médecine, Necker-Enfants Malades, Paris, France.
Millanvoye-Van Brussel
E M
EM
Simon
J M
JM
Duval
D P
DP
D000818:Animals; D016718:Arachidonic Acid / Q000378:metabolism; D002478:Cells, Cultured; D003327:Coronary Disease / Q000378:metabolism; D005227:Fatty Acids / Q000378:metabolism; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism; D008563:Membrane Lipids / Q000378:metabolism*; D009206:Myocardium / Q000166:cytology / Q000378:metabolism*; D010741:Phospholipases A / Q000037:antagonists & inhibitors; D010743:Phospholipids / Q000378:metabolism*
D005227:Fatty Acids; D008563:Membrane Lipids; D010743:Phospholipids; D016718:Arachidonic Acid; D010741:Phospholipases A