Calcium metabolism in normal and thyro-parathyroidectomized goats.
1. The effects of thyro-parathyroidectomy on calcium metabolism in the goat have been investigated using stable calcium balance techniques and the isotopes (45)Ca, (47)Ca and (85)Sr.2. Thyro-parathyroidectomized goats, whether receiving supplementary thyroxine or not, are in negative calcium balance, whereas normal or thyroidectomized animals are in positive balance.3. Gastro-intestinal absorption of (45)Ca is less in thyro-parathyroidectomized goats, whether receiving supplementary thyroxine or not, than in either normal goats or thyroidectomized goats receiving thyroxine supplements.4. The rate of endogenous secretion of calcium into the gastro-intestinal tract is unchanged by either thyroidectomy or thyro-parathyroidectomy. Urinary excretion of calcium is also apparently unchanged.5. The bone calcium accretion rate is reduced to approximately the same extent in thyroidectomized and thyro-parathyroidectomized goats. Thyroxine supplements restore the bone accretion rate of both groups of animals to normal or greater than normal levels.6. The bone calcium resorption rate is greater in thyro-parathyroidectomized goats, whether receiving thyroxine supplements or not, than in either normal goats or thyroidectomized goats receiving thyroxine supplements.
D000818:Animals; D001862:Bone Resorption / Q000502:physiology; D002118:Calcium / Q000378:metabolism* / Q000652:urine; D006041:Goats; D007408:Intestinal Absorption / Q000502:physiology; D008297:Male; D010280:Parathyroid Glands / Q000502:physiology*; D011874:Radiometry; D013961:Thyroid Gland / Q000502:physiology*; D013965:Thyroidectomy; D013974:Thyroxine / Q000627:therapeutic use
D013974:Thyroxine; D002118:Calcium