title: Increased calcium influx in caudal artery of rats made hypertensive with pyridoxine deficiency.
abstract: Moderate pyridoxine deficiency in rats has been shown to induce hypertension, which can be corrected by pyridoxine supplementation. In this study, calcium handling by isolated caudal arteries from pyridoxine-deficient and age-matched control rats was evaluated. We found 45Ca influx into the intracellular compartment to be significantly elevated in deficient rats. This increased influx could be attenuated with nifedipine, a calcium channel blocker, in a dose-dependent manner, suggesting alterations in the calcium channels that would make them leaky. The pyridoxine-deficient arterial segments maintained a higher resting tone; removal of extracellular calcium by EGTA or entry blockade by nifedipine decreased the tone significantly in the deficient arteries, compared with little or no effect in controls.
authors.affiliation: Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Manitoba, Winnipeg, Canada.
authors.forename: M
authors.initials: M
authors.lastname: Viswanathan
authors.forename: R
authors.initials: R
authors.lastname: Bose
authors.forename: K
authors.initials: K
authors.lastname: Dakshinamurti
mesh_terms: D000818:Animals; D001158:Arteries / Q000187:drug effects / Q000378:metabolism; D001693:Biological Transport, Active / Q000187:drug effects; D002118:Calcium / Q000378:metabolism*; D015220:Calcium Channels / Q000187:drug effects / Q000378:metabolism; D004533:Egtazic Acid / Q000494:pharmacology; D006973:Hypertension / Q000209:etiology / Q000378:metabolism*; D066298:In Vitro Techniques; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000378:metabolism*; D009543:Nifedipine / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D026681:Vitamin B 6 Deficiency / Q000150:complications
chemical_list: D015220:Calcium Channels; D004533:Egtazic Acid; D009543:Nifedipine; D002118:Calcium