Exchangeable sodium in DOC-salt and post-DOC-salt hypertension in rats.
Eighteen male Sprague-Dawley rats were fed a sodium-free diet and given NaCl (154 mmol/l) labelled with 22Na (37 Bq/l [1 microCi/l]) to drink. Following equilibration, each had a unilateral nephrectomy; 10 days later the animals started a series of 10 injections of deoxycorticosterone (12.5 mg twice-weekly for 5 weeks). Thereafter the animals were split into two groups, one to continue with DOC injections and diet as previously (DOC-salt), the other to stop DOC injections and continue a sodium-free diet and labelled saline of lower concentration (89 mmol/l) (post-DOC). During the period of DOC injections to both groups, blood pressure and exchangeable sodium rose significantly and were significantly correlated. In the post-DOC group, hypertension persisted and was not significantly different from that in the DOC-salt group. However, in the post-DOC-salt group, exchangeable sodium fell to levels similar to those found in uninephrectomized control animals of similar age which had never been given DOC or a high salt intake and had never been hypertensive. Thus an expanded sodium space does not contribute to maintenance of hypertension in the post-DOC-salt model.
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D003900:Desoxycorticosterone / Q000494:pharmacology*; D004039:Diet, Sodium-Restricted; D006973:Hypertension / Q000139:chemically induced* / Q000378:metabolism; D008297:Male; D009392:Nephrectomy; D051381:Rats; D011919:Rats, Inbred Strains; D012083:Renin / Q000097:blood; D012964:Sodium / Q000378:metabolism*; D012965:Sodium Chloride / Q000494:pharmacology*
D003900:Desoxycorticosterone; D012965:Sodium Chloride; D012964:Sodium; D012083:Renin