An assay for determination of rat adrenal catechol-O-methyltransferase activity: comparison of spontaneously hypertensive rats and Wistar-Kyoto rats.
A method has been developed for measurement of catechol-O-methyltransferase (COMT) activity in the rat adrenal gland. Epinephrine, synthesized in the adrenal gland, was used as substrate, and its enzymatic product, metanephrine, was quantified by high-performance liquid chromatography (HPLC) with fluorescence detection. The method has sufficient precision and accuracy. Soluble (S) and membrane-bound (MB) COMT activity in Wistar-Kyoto (WKY) rats was 20.7 +/- 3.5 and 18.6 +/- 3.4 pmol min(-1) mg(-1) protein (n = 5), respectively. To clarify the role of adrenal COMT in blood-pressure regulation, S and MB COMT activity in spontaneously hypertensive rats were determined. Respective activity was 18.6 +/- 3.4 and 17.0 +/- 1.1 pmol min(-1) mg(-1) (n = 5), which is similar to that in WKY rats. This finding suggests that COMT in the adrenal gland might not be related to blood pressure regulation.
Tsunoda
Makoto
M
Laboratory of Bio-Analytical Chemistry, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan. makotot@mol.f.u-tokyo.ac.jp
Imai
Kazuhiro
K
D000311:Adrenal Glands / Q000201:enzymology* / Q000378:metabolism; D000818:Animals; D002394:Catechol O-Methyltransferase / Q000032:analysis* / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D004789:Enzyme Activation; D004837:Epinephrine / Q000096:biosynthesis; D005453:Fluorescence; D008297:Male; D008676:Metanephrine / Q000032:analysis / Q000378:metabolism; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY
D008676:Metanephrine; D002394:Catechol O-Methyltransferase; D004837:Epinephrine