Kinetic characteristics of monoamine oxidase and serum cholinesterase in several related rat strains

✍ Scribed by J. S. Bellin; J. M. Sorrentino

• Book ID: 104785072
• Publisher: Springer
• Year: 1974
• Tongue: English
• Weight: 388 KB
• Volume: 11
• Category: Article
• ISSN: 0006-2928
• DOI: 10.1007/bf00485998

✦ Synopsis

This study was performed in order to delineate differences in kinetic enzyme characteristics of brain monoamine oxidase (MAO) and plasma cholinesterase (ChE) derived from the Walker-Walker (Fawn Hooded, FH) rat and from its putative ancestors, the Wistar ( W) and Long-Evans (LE). As compared with the enzyme isolated from the other two strains, brain MAO from FH has both a higher Vma x and increased reaction rate at lower substrate concentrations. It may thus be described as a "more efficient" enzyme. This study confirms previous work which shows that plasma ChE activity of females is higher than that of males. Fluoride ion is a noncompetitive inhibitor of the Wistar ChE, is a competitive inhibitor of the FH enzyme, and has no effect on the LE enzyme. Dibucaine is a competitive inhibitor in all cases except one: ChE derived from the FH female is uncompetitively inhibited. A comparison of the inhibitor constants shows that FH ChE is more resistant to Dibueaine than is that of W, and that LE is the most sensitive. FH eholinesterase is twice as resistant to the action of fluoride as is the Wistar enzyme.