Sheehan症候群患者における下垂体TSH分泌動態の再評価

概要

論文の詳細を見る
Serum concentrations of thyroid-stimulating hormone (TSH) were determined, using a highly sensitive immunoradiometric assay (IRMA), in 10 patients with Sheehan's syndrome. Serum TSH levels in these patients were from 2.3 to 9.0μU/ml, with the mean of 6.4±2.3 (SD) μU/ml, and the data were similar to those measured by a conventional RIA method. The levels of serum TSH in these patients were normal or even higher than those of healthy women (1.8±1.3μU/ml). After supplement therapy by cortisol, serum TSH levels decreased, but remained within the detectable range that was greater than 0.15μU/ml. After supplement therapy by l-thyroxine (T4), serum TSH levels moderately decreased in all patients, and excessive l-T4 administration resulted in a fall of serum TSH levels to lower than the detectable limit. Thyroidal 123I uptake was low in 3 out of 6 patients examined, which supports a recent hypothesis of reduced biological activity of the patient's TSH. While, the remaining 3 patients had normal thyroidal 123I uptake, and administration of perchlorate had no effects on thyroidal radioactivity. Thus, it may be possible that in the former group of patients the TSH has a reduced biological activity, and in the latter group of patients, iodine trapping is intact but further synthesis and secretion of thyroid hormone from the gland are impaired. When the response of serum TSH to TRH was examined, the peak serum TSH levels increased in all patients. The peak TSH levels were 4.8 to 10.2μU/ml with the mean of 7.5 μU/ml, but the data overlapped with those of normal subjects (peak level ranging 5.9-27.7 μU/ml). When the response was analyzed by a percent incitement from the basal level, the patients had only 93-250% increase after TRH, while normal subjects had 288-2339% increase, and there was no overlap between the two groups. Our data indicate that the diagnosis of pituitary hypothyroidism cannot be established by determination of only basal level of serum TSH, but the analysis of percent increases of serum TSH in response to TRH gives us useful information for the diagnosis of this syndrome.

Sheehan症候群患者における下垂体TSH分泌動態の再評価

スポンサーリンク

概要

著者

関連論文

スポンサーリンク