Organ culture: a new model for vascular endothelium dysfunction.
BACKGROUND
Endothelium dysfunction is believed to play a role in the development of cardiovascular disease. The aim of the present study was to evaluate the suitability of organ culture as a model for endothelium dysfunction.


METHODS
The isometric tension was recorded in isolated segments of the rat mesenteric artery branch, before and after organ culture for 20 h. Vasodilatation was expressed as % of preconstriction with U46619. The acetylcholine (ACh) induced nitric oxide (NO) mediated dilatation was studied in the presence of 10 microM indomethacin, 50 nM charybdotoxin and 1 microM apamin. Endothelium-derived hyperpolarising factor (EDHF) was studied in the presence of 0.1 mM L-NOARG and indomethacin. Prostaglandins were studied in the presence of L-NOARG, charybdotoxin and apamin.


RESULTS
The ACh-induced NO and prostaglandin-mediated dilatations decreased significantly during organ culture (NO: 84% in control and 36% in cultured; prostaglandins: 48% in control and 16% in cultured). Notably, the total ACh-dilatation was not changed. This might be explained by the finding that EDHF alone stimulated a full dilatation even after organ culture (83% in control and 80% in cultured). EDHF may thereby compensate for the loss in NO and prostaglandin-mediated dilatation. Dilatations induced by forskolin or sodium nitroprusside did not change after organ culture, indicating intact smooth muscle cell function.


CONCLUSIONS
Organ culture induces a loss in NO and prostaglandin-mediated dilatation, which is compensated for by EDHF. This shift in mediator profile resembles that in endothelium dysfunction. Organ culture provides an easily accessible model where the molecular changes that take place, when endothelium dysfunction is developed, can be examined over time.
Alm
Rikard
R
Experimental Vascular Research, Department of Internal Medicine, Lund University Hospital, Lund, Sweden. rikard.alm@med.lu.se
Edvinsson
Lars
L
Malmsjö
Malin
M
D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid / Q000494:pharmacology; D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001030:Apamin / Q000494:pharmacology; D001685:Biological Factors / Q000502:physiology*; D018999:Charybdotoxin / Q000494:pharmacology; D004730:Endothelium, Vascular / Q000187:drug effects / Q000503:physiopathology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D007213:Indomethacin / Q000494:pharmacology; D008638:Mesenteric Arteries; D009569:Nitric Oxide / Q000502:physiology; D019335:Nitroarginine / Q000494:pharmacology; D009924:Organ Culture Techniques; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors; D014652:Vascular Diseases / Q000503:physiopathology*; D014662:Vasoconstrictor Agents / Q000494:pharmacology; D014664:Vasodilation / Q000187:drug effects* / Q000502:physiology
D001685:Biological Factors; D004791:Enzyme Inhibitors; D014662:Vasoconstrictor Agents; C067410:endothelium-dependent hyperpolarization factor; D018999:Charybdotoxin; D019335:Nitroarginine; D001030:Apamin; D009569:Nitric Oxide; D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; D000109:Acetylcholine; D007213:Indomethacin