title: Calcitonin stimulation of urine flow and sodium excretion in the starling.
abstract: Renal effects of synthetic salmon calcitonin (CT) were examined in normal and parathyroidectomized (PTX) starlings, Sturnus vulgaris. Standard clearance studies were performed. Anesthetized birds were infused with [14C]-inulin in 2.5% mannitol containing either 0.25% gelatin alone as a control, or gelatin plus CT (2 IU CT/h; Armour). In intact starlings, CT significantly increased urine flow and relative clearance of sodium (CNa/CIn). CCa/CIn was significantly elevated only 40 min after start of hormone infusion. No significant change occurred in CK/CIn, CPO4/CIn or in serum levels of Na, K, Ca, or PO4. In PTX starlings, CT induced significantly higher CNa/CIn. Urine flow was significantly higher at 40 and 60 min, whereas CK/CIn increased significantly only 20 min following start of CT infusion. Serum calcium decreased significantly 1 h after hormone administration and was accompanied by increased incidence of tetany. Serum phosphate levels were significantly lower than those of corresponding PTX controls 1 h post-CT, indicating that CT prevented the expected hyperphosphatemia. Higher CT dose (20 IU/h) in PTX birds substantially enhanced urine flow, CNa/CIn, CK/CIn, and occurrence of tetany.
mesh_terms: D000818:Animals; D001717:Birds / Q000502:physiology*; D002116:Calcitonin / Q000494:pharmacology*; D002118:Calcium / Q000097:blood; D007668:Kidney / Q000502:physiology*; D010280:Parathyroid Glands / Q000502:physiology; D010710:Phosphates / Q000097:blood; D011188:Potassium / Q000097:blood; D012964:Sodium / Q000097:blood / Q000502:physiology*; D014556:Urine / Q000502:physiology*
chemical_list: D010710:Phosphates; D002116:Calcitonin; D012964:Sodium; D011188:Potassium; D002118:Calcium