title: NaCl ingestion ameliorates plasma indexes of calcium deficiency.
abstract: Rats deprived of dietary calcium ingest large volumes of concentrated NaCl solutions. To examine why, some physiological consequences of ingesting NaCl solution were measured. Male Sprague-Dawley rats fed diet containing 150 or 25 mmol Ca2+/kg were killed at 20, 40, 80, or 160 min after they started to drink solutions of 0.125% saccharin+3% glucose (S+G), 50 mM CaCl2, or 300 mM NaCl. Relative to rats fed the 25 mmol Ca2+/kg diet given nothing to drink, those fed the same diet that drank NaCl or CaCl2 but not S+G had elevated plasma ionized calcium concentrations and reduced plasma parathyroid hormone (PTH) concentrations. Rats fed the 150 mmol Ca2+/kg diet did not show these changes. In a follow-up experiment, rats fed the 25 mmol Ca2+/kg diet that drank NaCl had elevated plasma ionized calcium and reduced PTH and 1,25-dihydroxyvitamin D concentrations over the following 4-6 h. An in vitro study found that plasma ionized calcium concentrations were modulated by NaCl concentration directly. These findings indicate that NaCl ingestion can temporarily enhance the calcium status of calcium-deprived rats.
authors.affiliation: Monell Chemical Senses Center, Philadelphia, Pennsylvania 19104, USA. tordoff@pobox.upenn.edu
authors.forename: M G
authors.initials: MG
authors.lastname: Tordoff
mesh_terms: D000324:Adrenocorticotropic Hormone / Q000097:blood; D000450:Aldosterone / Q000097:blood; D000704:Analysis of Variance; D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D001798:Blood Proteins / Q000378:metabolism*; D002116:Calcitonin / Q000097:blood; D002117:Calcitriol / Q000097:blood*; D002118:Calcium / Q000097:blood* / Q000172:deficiency*; D002122:Calcium Chloride / Q000494:pharmacology; D003345:Corticosterone / Q000097:blood; D006728:Hormones / Q000097:blood*; D007328:Insulin / Q000097:blood; D008297:Male; D010281:Parathyroid Hormone / Q000097:blood*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012083:Renin / Q000097:blood; D012964:Sodium / Q000097:blood; D017673:Sodium Chloride, Dietary / Q000494:pharmacology*; D014882:Water-Electrolyte Balance
chemical_list: D001786:Blood Glucose; D001798:Blood Proteins; D006728:Hormones; D007328:Insulin; D010281:Parathyroid Hormone; D017673:Sodium Chloride, Dietary; D000450:Aldosterone; D000324:Adrenocorticotropic Hormone; D002116:Calcitonin; D012964:Sodium; D012083:Renin; D002117:Calcitriol; D002122:Calcium Chloride; D002118:Calcium; D003345:Corticosterone