Volume 8, Number 1, p.p. 23–26
Thyroid pathologies and alteration of HCO3– -ATPase activity
K. Menabde, M. Chipashvili, N. Zaalishvili and N. Koshoridze*
Department of Biology, I. Javakhishvili State University, 2 University St, 0128 Tbilisi, Georgia
The distribution of the Mg2+-dependent,HCO3--stimulated ATPase (HCO3– -ATPase) has been investigated in subcellular fractions of the tissue of the human thyroid gland. It was found that especially high enzymatic activity is characteristic of mitochondria and the endoplasmic reticulum. Correlation between various pathologies of the thyroid and HCO3- -ATPase activity was demonstrated. During development of the various pathologies, the subcellular fractions of the gland showed uneven alterations of HCO3– -ATPase activity. Intriguingly, the enzyme kinetic parameters are also changed, i.e. in the different pathologies both enzyme activity and its affinity towards bicarbonate ions are altered. This raises the question whether pathology is caused by, or results in, changes in the enzyme at the molecular level.
Keywords:
adenoma, carcinoma, diffuse-nodular goitre, HCO3– -ATPase, thyroid gland