Summary
Experiments were performed to test the hypothesis that insulin has a role in the pathogenesis of atherosclerosis. Rats were injected intravenously with sodium (1-14C)-acetate (10 μCi per 100 g weight) with and without insulin (100000 μ units per 100 g weight). After one hour, they were killed, and the lipids extracted from the cleaned aortas. The lipids were separated by thin layer chromatography, and the radioactivity in the total lipids and the lipid fractions was measured. The results showed that insulin stimulated the incorporation of sodium (1-14C)-acetate into total lipids, cholesterol and phospholipids to a significant extent. Incorporation into triglyceride just failed to reach statistical significance. These results are compatible with some of the features of human atherosclerosis, and support the hypothesis that insulin and atheroma are causally linked. The finding that insulin had an effect on cholesterol metabolism was unexpected and warrants further investigation.
Résumé
On a soumis à l'expérience l'hypothèse que l'insuline joue un rôle dans la pathogénèse de l'athérosclérose. De l'acétate de sodium 1-14C (10 μCi par 100 g de poids) avec et sans insuline (100000 μ unités par 100 g de poids) a été injecté à des rats, par voie intra-veineuse. Une heure après, ils ont été tués et les lipides extraits de l'aorte nettoyée. Les lipides ont été séparés par Chromatographie en couche mince et la radioactivité a été mesurée dans les lipides totaux et les fractions de lipides. Les résultats ont montré que l'insuline a stimulé l'incorporation de l'acétate de sodium 1-14C dans les lipides totaux, le cholestérol et les phospholipides d'une façon significative. L'incorporation dans les triglycérides n'atteignait pas la significativité. Ces résultats sont compatibles avec quelques aspects de l'athéro-sclérose chez l'homme et viennent appuyer l'hypothèse d'une étroite liaison entre l'insuline et l'athérome. On ne s'attendait pas à découvrir que l'insuline avait un effet sur le métabolisme du cholestérol et cela implique de nouvelles recherches.
Zusammenfassung
Es wurden Versuche durchgeführt, um die Hypothese zu prüfen, ob Insulin eine Rolle in der Pathogenese der Arteriosklerose spielt. Zu diesem Zweck wurden Ratten intravenös (1-14C-Natriumacetat (10 μCi pro 100 g Körpergewicht) mit und ohne Insulin (100000 μE pro g Gewicht) injiziert. Nach einer Stunde wurden die Tiere getötet und die Lipide aus den gereinigten Aorten extrahiert. Die Lipide wurden durch Dünnschichtchromatographie getrennt, dann wurde die Radioaktivität in den Gesamtlipiden und den Lipidfraktionen gemessen. Die Ergebnisse zeigten, daß Insulin die Inkorporation von (1-14C)-Natriumacetat in die Gesamtlipide, das Cholesterin und die Phospholipide in signifikantem Ausmaße stimuliert. Die Inkorporation in die Triglyceride war gerade eben statistisch nicht signifikant. Diese Ergebnisse sind vereinbart mit einigen Charakteristica der menschlichen Arteriosklerose und unterstützten die Hypothese, daß Insulin und Atherom ursächlich verknüpft sind. Der Befund, daß Insulin eine Einwirkung auf den Cholesterinstoffwechsel hat, war unerwartet und erfordert weitere Untersuchungen.
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This work formed part of a thesis accepted for the degree of MD (Belfast) 1970.
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Stout, R.W. The effect of insulin on the incorporation of sodium (1-14C)-acetate into the lipids of the rat aorta. Diabetologia 7, 367–372 (1971). https://doi.org/10.1007/BF01219472
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DOI: https://doi.org/10.1007/BF01219472