In vivo effects of isatin on certain enzymes, lipids & serotonergic system of rat brain

Isatin (10 microM) strongly inhibited the activity of rat brain monoamine oxidase-B (MAO-B) in vitro. At millimolar concentrations (1-10 mM) it inhibited brain acetylcholinesterase (AChE) and sodium, potassium-adenosine triphosphatase (Na+, K(+)-ATPase) activity also. However, isatin did not affect these enzymes after both acute and chronic treatments in vivo. Administration of isatin to rats at 300 mg/kg body weight for 2 and 6 h significantly raised brain serotonin levels. Chronic treatment for 20 days resulted in enhanced brain glycolipids and plasmalogen levels. There was no change in the levels of 5-hydroxy indole acetic acid (5 HIAA), phospholipids, cholesterol and gangliosides under these conditions.