Parathyroid function in hyperthyroidism.

Increased calcium and phosphorus excretion(Aub et al., 1929, Robertson, 1942) as well as decalcification of the skeletal system(Koppen, 1892; Plummer, 1928; Dunlap and Moor, 1929; Hunter, 1930; Askanazy and Rutishauser, 1933; Martos, 1938; Bartels and Haggart, 1938; Brunner, 1940; Stanley and Fazekas, 1949: Nielsen, 1952; Rose and Boles, 1953; Laake 1955; Epstein et al. 1958)has been frequently observed in hyperthyroidism. The increased excretion usually returns to normal after successful treatment surgically or with antithyroid medication(Robertson, 1942; Green and Lyall, 1951). The bones in clinical hyperthyroidism and in thyroid -fed animals are usually poor in calcium content (Smith and Mclean, 1938; Drill, 1941). Aub et al.(1929)were of the opinion that osteoporosis developed in hyperthyroidism due to the wasting of bone matrix by the special catabolic action of thyroid hormone. Histologically, however, osteitis fibrosa generalisata similar to that seen in the bones of hyperparathyroidism was observed in many cases of hyperthyroidism(Follis, 1953). Studies of Krane et al.(1956)using Ca45 observing increased bone formation and destruction in hyperthyroidism also suggested changes similar to osteitis fibrosa generalisata instead of osteoporosis. Hansman and Wilson (1934)suggested cocxistence of hyperparathyroidism to explain the metabolic