Acetazolamide-insensitive carbonic anhydrase activities in liver and tonic skeletal muscle of adult male rats with streptozotocin-induced diabetes mellitus

Abstract

One of the four discrete isoenzymes of carbonic anhydrase hitherto characterized, CA III, has the lowest turnover rate and the greatest resistance to inhibition by sulphonamides. Streptozotocin-induced diabetes mellitus resulted in a reduction in acetazolamide-resistant activity of carbonic anhydrase in the liver, but not in tonic skeletal muscle, of adult male rats. The hepatic activity declined with apparent first-order kinetics [calculated rate constant (k) 0.089 day-1] to a minimum of approx. 6% of control values; the reduction in activity was moderated by administration of insulin.

Effects of Gentamicin Sulfate on Enzyme Activities of Carbonic Anhydrase from Human Erythrocytes in Vitro and from Rat Erythrocytes in Vivo.

“…For example, in two recent studies, total hepatic CA (IϩIIϩIIIϩIV) activity was shown to be diminished in the streptozotocin-induced diabetic rat. 22,23) Gluconeogenesis and ureagenesis were also associated with an increase in hepatic CA-V activity. 22) In addition, hepatic pH disequilibrium was explained in terms of changes in CA activity.…”

Morphine Inhibits Erythrocyte Carbonic Anhydrase in Vitro and in Vivo

“…22) Gluconeogenesis and ureagenesis were also associated with an increase in hepatic CA-V activity. 23) There is convincing evidence for over expression of CA-IX and CA-XII in cancer, 24) acidifying the extracellular matrix, which is thought to promote growth of the tumour. Solid tumours are often hypoxic, and expression of CA-IX and CA-XII is upregulated under these conditions.…”

In Vitro and in Vivo Effects of Dantrolene on Carbonic Anhydrase Enzyme Activities

“…27) Gluconeogenesis and ureagenesis were also associated with an increase in hepatic CA-V activity. 28) In addition, hepatic pH disequilibrium was explained in terms of changes in CA activity. Furthermore, many drug side effects are believed to result from CA isozyme inhibition.…”