Yoshida K, Kiso Y, Kurihara H, Kaise K, Kaise N, Fukazawa H, Mori K, Kikuchi K, Yoshinaga K
Department of Clinical Biology and Hormonal Regulation, Tohoku University School of Medicine, Sendai, Japan.
Endocrinol Jpn. 1991 Aug;38(4):363-7. doi: 10.1507/endocrj1954.38.363.
We recently reported that the red blood cell (RBC) carbonic anhydrase I (CAI) concentration in patients with hyperthyroidism is reduced and reflects the patient's mean thyroid hormone level over the preceding months. In this study, RBC CAI concentrations were measured in patients with thyroid nodules who were receiving suppressive doses of thyroxine (group I) and compared with those obtained in patients with primary hypothyroidism receiving replacement doses of thyroxine (group 2). Of the 17 patients in group 1, 16 (94%) had elevated plasma free T4 levels, but all 17 had normal free T3 levels. Of the 17 patients in group 2, 16 (94%) had normal free T4 levels and all 17 had normal free T3 levels. Plasma TSH concentrations in group 1 were all below the lower limit of sensitivity of 0.04 mU/l. In group 2, 11 had normal and 6 had slightly elevated plasma TSH concentrations. The mean (+/- SD) RBC CAI concentration in group 1 (300 +/- 53 nmol/g Hb) was significantly lower than that in group 2 (340 +/- 57 nmol/g Hb). The RBC CAI concentration was significantly correlated with both the concentration of plasma free T4 and free T3. These observations indicate that in patients receiving suppressive doses of thyroxine a slight increase in the plasma free T4 concentration produces a slight but significant decrease in RBC CAI levels.
我们最近报道，甲状腺功能亢进患者的红细胞（RBC）碳酸酐酶I（CAI）浓度降低，且反映了患者前几个月的平均甲状腺激素水平。在本研究中，对接受甲状腺素抑制剂量治疗的甲状腺结节患者（第一组）测定了RBC CAI浓度，并与接受甲状腺素替代剂量治疗的原发性甲状腺功能减退患者（第二组）的测定结果进行比较。第一组的17例患者中，16例（94%）血浆游离T4水平升高，但17例患者的游离T3水平均正常。第二组的17例患者中，16例（94%）游离T4水平正常，17例患者的游离T3水平均正常。第一组的血浆促甲状腺激素（TSH）浓度均低于0.04 mU/l的灵敏度下限。在第二组中，11例患者的血浆TSH浓度正常，6例略有升高。第一组的平均（±标准差）RBC CAI浓度（300±53 nmol/g Hb）显著低于第二组（340±57 nmol/g Hb）。RBC CAI浓度与血浆游离T4和游离T3浓度均显著相关。这些观察结果表明，在接受甲状腺素抑制剂量治疗的患者中，血浆游离T4浓度的轻微升高会导致RBC CAI水平轻微但显著降低。
