Monoamine oxidase and semicarbazide-sensitive amine oxidase activities in isolated cardiomyocytes of spontaneously hypertensive rats.
In the isolated cardiomyocytes of spontaneously hypertensive rats (SHR, 3 months old) MAO A and B activities were significantly increased compared to the myocytes in the hearts of age-matched Wistar-Kyoto rats. This increase was not associated with cardiac hypertrophy in these young animals, but might represent an early event in the development of hypertrophy. A semicarbazide-sensitive amine oxidase (SSAO) activity was found in cardiomyocytes. This activity showed a high affinity for benzylamine (Km 5-6 microM) and was not inhibited by 10(-4) M pargyline and 10(-5) M deprenyl, but was largely inhibited by 10(-4) M B24 (3,5-diethoxy-4-aminomethylpyridine), a specific inhibitor of semicarbazide-sensitive amino oxidase with high affinity for benzylamine. The SSAO enzyme of rat cardiomyocytes is a copper-amine oxidase and has a crossreactivity with the antibodies raised against pure pig plasma benzylamine oxidase. In the cardiomyocytes of 3-month old SHR rats the level of this enzymic activity is not significantly increased.
Pino
R
R
Department of Pharmacology, University of Florence, Italy.
Failli
P
P
Mazzetti
L
L
Buffoni
F
F
D006631:Amine Oxidase (Copper-Containing) / Q000737:chemistry / Q000378:metabolism*; D000818:Animals; D002469:Cell Separation; D004789:Enzyme Activation; D005455:Fluorescent Antibody Technique; D006973:Hypertension / Q000201:enzymology; D007150:Immunohistochemistry; D008297:Male; D008995:Monoamine Oxidase / Q000378:metabolism*; D009206:Myocardium / Q000166:cytology / Q000201:enzymology*; D009929:Organ Size; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D012663:Semicarbazides
D012663:Semicarbazides; C010059:carbamylhydrazine; D006631:Amine Oxidase (Copper-Containing); D008995:Monoamine Oxidase