Urinary cyclic AMP in hyperthyroidism.

Urinary cyclic AMP was studied in 22 female and in 6 male hyperthyroid normocalcemic patients and in 3 hyperthyroid hypercalcemic men. Cyclic AMP/creatinine ratios were elevated both in female (4.12 +/- 0.26 mumoles/gm creatinine) and male (3.92 +/- 0.41 mumoles/gm creatinine) hyperthyroid normocalcemic patients as compared with normal female and male controls (2.85 +/- 0.20 and 2.54 +/- 0.14 mumoles/gm creatinine, respectively). However, there was no difference in the 24-hour urinary cyclic AMP excretion of both hyperthyroid and normal subjects. The hyperthyroid hypercalcemic men excreted less (2.47 +/- 0.19) mumoles/24 hr) cyclic AMP/24 hr than the normal male controls. In the thirteen female patients, studied when euthyroid, the cyclic AMP/creatinine ratio was normalised.