Calcium deficiency alters chorda tympani nerve responses to oral calcium chloride.
As a preliminary examination of the influence of calcium deficiency on gustatory sensitivity to calcium, we recorded electrophysiological responses of the chorda tympani nerve of calcium-replete and calcium-deprived rats. Relative to rats fed calcium-replete diet, rats fed low calcium diet had lower electrophysiological response thresholds to CaCl2 (300 vs. 30 microM) and calcium lactate (300 vs. 100 microM) but not NaCl. The calcium-deprived animals had a greater chorda tympani response to 30, 100 and 300 microM CaCl2 and 30 and 100 microM calcium lactate but a smaller chorda tympani response to 30, 100 and 300 mM CaCl2 and to 100 mM MgCl2. A behavioral study using an ascending series of 48-h two-bottle preference tests showed that the threshold for acceptance of CaCl2 was similar to the electrophysiological threshold (310 microM in replete rats, 100 microM in calcium-deprived rats). These findings raise the possibility that changes in calcium status influence the perception of calcium, which, in turn, influences calcium intake.
Inoue
M
M
Monell Chemical Senses Center, Philadelphia, PA 19104-3308, USA.
Tordoff
M G
MG
D000818:Animals; D002118:Calcium / Q000172:deficiency*; D002122:Calcium Chloride / Q000494:pharmacology; D017610:Calcium Compounds / Q000494:pharmacology; D002136:Calcium, Dietary / Q000008:administration & dosage*; D002814:Chorda Tympani Nerve / Q000187:drug effects* / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D007773:Lactates / Q000494:pharmacology; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D012965:Sodium Chloride / Q000494:pharmacology; D013649:Taste / Q000187:drug effects* / Q000502:physiology
D017610:Calcium Compounds; D002136:Calcium, Dietary; D007773:Lactates; C110051:calcium lactate; D012965:Sodium Chloride; D002122:Calcium Chloride; D002118:Calcium