Vitamin C deficiency exerts paradoxical cardiovascular effects in osteogenic disorder Shionogi (ODS) rats.
Vitamin C is considered to be a very efficient water-soluble antioxidant, for which several new cardiovascular properties were recently described. The aim of this study was to determine in vivo the effects of a severe depletion of vitamin C on cardiac and vascular variables and reperfusion arrhythmias. For this purpose, we used a mutant strain of Wistar rats, osteogenic disorder Shionogi (ODS). After 15 d of consuming a vitamin C-deficient diet, ODS rats had a 90% decrease in plasma and tissue levels of ascorbate compared with ODS vitamin C-supplemented rats and normal Wistar rats. However, plasma antioxidant capacity, proteins, alpha-tocopherol, urate, catecholamines, lipids, and nitrate were not influenced by the vitamin C deficiency in ODS rats. Moreover, there was no difference between ODS vitamin C-deficient and -supplemented rats in heart rate and arterial pressure. After 5 min of an in vivo regional myocardial ischemia, various severe arrhythmias were observed, but their intensities were not modified by vitamin C in vitamin C-deficient ODS rats. The vascular reactivity, measured in vitro on thoracic arteries, was not altered by ascorbate deficiency in ODS rats. These unexpected results suggest that unidentified compensatory mechanisms play a role in maintaining normal cardiac function and vascular reactivity in vitamin C-deficient rats.
Vergely
Catherine
C
Laboratoire de Physiopathologie et Pharmacologie Cardio-vasculaires Expérimentales, IFR n degrees 100, Facultés de Médecine et Pharmacie, 21000 Dijon, France. catherine.vergely@u-bourgogne.fr
Goirand
Françoise
F
Ecarnot-Laubriet
Aline
A
Renard
Céline
C
Moreau
Daniel
D
Guilland
Jean-Claude
JC
Dumas
Monique
M
Rochette
Luc
L
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001011:Aorta; D001145:Arrhythmias, Cardiac / Q000209:etiology; D001205:Ascorbic Acid / Q000008:administration & dosage; D001206:Ascorbic Acid Deficiency / Q000150:complications* / Q000503:physiopathology; D001794:Blood Pressure; D001847:Bone Diseases / Q000235:genetics* / Q000503:physiopathology; D002318:Cardiovascular Diseases / Q000188:drug therapy / Q000209:etiology*; D004032:Diet; D004837:Epinephrine / Q000097:blood; D006339:Heart Rate; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D017202:Myocardial Ischemia / Q000503:physiopathology; D015425:Myocardial Reperfusion / Q000009:adverse effects; D009638:Norepinephrine / Q000097:blood; D010012:Osteogenesis; D010656:Phenylephrine / Q000494:pharmacology; D051381:Rats; D011922:Rats, Mutant Strains; D017208:Rats, Wistar; D024502:alpha-Tocopherol / Q000097:blood
D010656:Phenylephrine; D024502:alpha-Tocopherol; D000109:Acetylcholine; D001205:Ascorbic Acid; D009638:Norepinephrine; D004837:Epinephrine