Distribution of Catechol‐o‐methyl Transferase in the Nervous System and Other Tissues

Abstract

O-METHYLATION has been shown to be the principal pathway for the metabolism of administered adrenaline and noradrenaline (AXELROD, INSCOE, SENOH and WITKOP, 1958; LABROSE, AXELROD and K m , 1958). An enzyme, catechol-0-methyl transferase (COMT),? which catalyses the transfer of a methyl group from S-adenosylmethionine to the 3-hydroxy group of catechois, has been described (AXELROD 1957; AXFLROD and TOMCHICK, 1958). Since the products, metanephrine (3-0-methyladrenaline) and normetanephrine (3-O-methylnoradrenaline), have negligible physiologd activity (EVARTS et a/., 1958), this enzyme may be of major importance in the inactivation of endogenously released catecholamine hormones. The functional role of catecholamines in the autonomic nervous system and the relatively high concentration of these amines in certain regions of the central nervous system (VOGT, 1954) suggested a study of the distribution of COMT in the nervous system and certain organs. METHODS A N D MATERIALS Prepation of tissues. Tissues were obtained from adult monkeys (Macaca mulatt), which were killed by exsanguination under pentobarbital anaesthesia. The tissues were dissected immediately Axaua, J. .ad Touoooc R (19S8)J. W. C k m . 233,702. Axumm J. .nd TOMM~CK R. (unpublbhcd obemtiom). B u m G. L 4 Gnzen16 S. S. (1957) J. Physid. 138, 81. EVANS E. V.. Giusspre L.. FLFMIW T. E. and ~D S M A. (1958) Proc. Sor. exp. Bid., N. r.

Distribution of catechol-O-methyltransferase enzyme in rat tissues.

“…The highest COMT enzyme activity has been found in the liver, followed by the submaxillary and parotid glands, pancreas, adenohypophysis, neurohypophysis, different brain areas, peripheral nerves and ganglia, and blood vessels (Axelrod et al, 1959). Despite the relatively wide and abundant distribution of the enzyme in rat tissues, the exact cellular localization of COMT is not completely known.…”

“…1975;Axelrod et al, 1959). Intense staining was also observed in kidneys, in which COMT activity is high (Guldberg and Marsden, 1975;Ax'elrod and Tomschik, 1958).…”

Immunocytochemical Localization of Catechol-O-Methyltransferase in Lymphoid Tissue and Bone Marrow of Rat

“…COMT is important in the enzymatic inactivation of circulating catecholamines (27,28), catecholamines released as neurotransmitters from both central and peripheral catecholamine containing neurons (9,18,24), xenobiotic catechols (3,14), and catecholestrogens (6,15). COMT activity is widely distributed in mammalian tissues (17,18) and has been clearly demonstrated in splenic tissue (1,2,19) and in erythrocytes (32,42). Biochemical studies indicate that COMT is present almost exclusively as a soluble cytoplasmic protein with a molecular size of 23000 Daltons (7,8) although several investigators have reported the presence of small amounts of membrane-bound COMT activity (7).…”

Effect of visual pattern restriction in early life on brain enzyme in the rat

“…The AChE fmdings will be reported elsewhere as a part 01" a more detailed paper. HIOMT activity in the pineal gland was determined by measuring the formation of melatonin methyl-14C produced from S-adenosylmethionine-methyl-14C and N -acetylserotonin, employing the procedure as reported by Axelrod et al (1961)_ RESULTS Experimental groups did not differ on emotionality rating either after 35 days or after 70 days in rearing conditions. However, significant differences in body weight were obtained for different groups, as evident in Table 1, which shows body weight for all experimental groups for four weighing periods.…”