Effect of intracerebroventricular calcitonin on renal hydromineral excretion in sheep.
The localization of calcitonin in hypothalamic tissue and cerebrospinal fluid and calcitonin binding sites in circumventricular organs suggests involvement in neural mechanisms, possibly hydromineral balance. Therefore, we compared the effects of intracerebroventricular and intravenous infusions of porcine calcitonin (0.04-0.05 mU X kg-1 X min-1) on renal water, Ca, Mg, Na, and K excretions. The intracerebroventricular administration of calcitonin for 60 min induced a pronounced increase (P less than 0.01) in free water clearance, from a preinfusion value of -0.73 +/- 0.45 to +3.02 +/- 1.15 ml/min at the end of the infusion. In contrast, the free water clearance was unaltered during the intravenous infusion of calcitonin. Renal Ca excretion fell significantly (53%) 40 min after the end of the intracerebroventricular infusion of calcitonin, whereas the corresponding intravenous infusion of calcitonin did not change (P greater than 0.05) urinary Ca excretion. Renal Mg excretion was increased (P less than 0.01) during the intracerebroventricular infusion of calcitonin but was not altered during intravenous infusion of calcitonin. Urinary excretions of Na and K were not affected by either intracerebroventricular or intravenous administration of calcitonin. It is concluded that calcitonin can act centrally to modify renal water, Ca, and Mg excretions.
D000818:Animals; D001834:Body Water / Q000378:metabolism*; D001921:Brain / Q000502:physiology*; D002116:Calcitonin / Q000494:pharmacology*; D002118:Calcium / Q000652:urine; D005260:Female; D007276:Injections, Intraventricular; D007668:Kidney / Q000378:metabolism*; D008274:Magnesium / Q000652:urine; D008903:Minerals / Q000652:urine*; D009994:Osmolar Concentration; D011188:Potassium / Q000652:urine; D012756:Sheep; D012964:Sodium / Q000652:urine
D008903:Minerals; D002116:Calcitonin; D012964:Sodium; D008274:Magnesium; D011188:Potassium; D002118:Calcium