Demori I, Bottazzi C, Fugassa E
Istituto di Fisiologia Generale, Università di Genova, Italy.
Horm Metab Res. 1995 May;27(5):221-5. doi: 10.1055/s-2007-979944.
Recently, an increase in gammaglutamyltranspeptidase (GGT) activity and mRNA in liver of hypothyroid rats has been reported. The aim of this study was to verify if triiodothyronine (T3) can directly affect GGT expression in primary cultures of rat hepatocytes. Results obtained from adult rat hepatocytes cultured in serum-free medium demonstrate: 1) a rise in GGT mRNA level magnified by dexamethasone during the maintenance of hepatocytes in culture which parallels the stimulation of GGT activity; 2) a negative effect of T3 on GGT activity of cultured hepatocytes which reflects a specific inhibition of GGT gene expression. The T3 effect on GGT expression in cultured hepatocytes is in line with previous observations on hypothyroid rat liver suggesting an important role for thyroid hormone in maintaining the differentiated adult liver phenotype in the rat.
最近，有报道称甲状腺功能减退大鼠肝脏中的γ-谷氨酰转肽酶（GGT）活性和mRNA增加。本研究的目的是验证三碘甲状腺原氨酸（T3）是否能直接影响大鼠原代肝细胞中GGT的表达。在无血清培养基中培养的成年大鼠肝细胞所获得的结果表明：1）在培养肝细胞的过程中，地塞米松可使GGT mRNA水平升高，这与GGT活性的刺激平行；2）T3对培养肝细胞的GGT活性有负面影响，这反映了对GGT基因表达的特异性抑制。T3对培养肝细胞中GGT表达的影响与先前对甲状腺功能减退大鼠肝脏的观察结果一致，表明甲状腺激素在维持大鼠成年肝脏分化表型方面具有重要作用。
