Mineralocorticoid treatment and the adrenalectomy-induced increase in monoamine oxidase activity

Summary Bilateral adrenalectomy in the rat results in an increase in heart monoamine oxidase activity in animals drinking water and in animals drinking 0.9% saline. Daily administration of deoxycorticosterone acetate prevented the increased monoamine oxidase activity in the animals drinking saline but not in those drinking water.Acknowledgment. This work was supported in part by a grant from the American Heart Association — Louisiana, Inc.     

Ontogenesis of monoamine oxidase in the thyroid gland of rats

Summary During postnatal development, MAO activity in the thyroid gland of male rats increases until day 16, when adult values are reached.     

Monoacylcadaverines as substrates for both monoamine oxidase and diamine oxidase; low rates of activity

Summary Monoacetylcadaverine and monopropionylcadaverine were found to be substrates for both rat liver monoamine oxidase and hog kidney diamine oxidase, but all the K_m-values for the oxidases were very high. The amines were common substrates for type A and type B monoamine oxidase.     

Chlorodimeform and its effect on monoamine oxidase activity in the cattle tick, Boophilus microplus.

The action of the acaricide, chlorodimeform and its metabolite. N-desmethylchlorodimeform, on the activity monoamine oxidase (MAO) from the cattle tick, Boophilus microplus, were studied. Both compounds were found to be potent in vitro and in vivo inhibitors of the enzyme. However the inhibition of MAO does not seem to be related to the toxic action of the acaricide.     

Distribution of noradrenaline and of monoamine oxidase and catechol-O-methyltransferase activity in human foetal heart

Zusammenfassung Die Konzentration von Noradrenalin und die Aktivität der MAO und COMT wurde in verschiedenen Teilen des menschlichen foetalen Herzens bestimmt. Die Ventrikel der Herzen (bis zu 12 Wochen alt) waren sehr noradrenalinarm. Die COMT-Aktivität des rechten Vorhofs war bis zur Mitte der Schwangerschaft viel niedriger als die der übrigen Herzgebiete. Die COMT- und MAO-Aktivität im Gewebe des Spatium zwischen der Aorta und der Arteria pulmonalis lag ungefähr in der gleichen Grössenordnung wie die der Ventrikel.     

Chlorodimeform and its effect on monoamine oxidase activity in the cattle tickBoophilus microplus

Summary The action of the acaricide, chlorodimeform and its metabolite, N-desmethylchlorodimeform, on the activity monoamine oxidase (MAO) from the cattle tick,Boophilus microplus, were studied, Both compounds were found to be potent in vitro and in vivo inhibitors of the enzyme. However the inhibition of MAO does not seem to be related to the toxic action of the acaricide.     

Effects of hypophysectomy, bilateral adrenalectomy and hormone replacement therapy upon organ monoamine oxidase activity.

Changes in MAO activity after hypophysectomy (HX) are not due to adrenal insufficiency. ACTH failed to reverse the effects of HX and enhanced the depression of cardiac and spleenic MAO. The data suggests both facilitatory and inhibitory effects of pituitary hormones on MAO activity.     

Adrenergic mechanism inTetrahymena. I. Changes in monoamine oxidase activity during growth

Zusammenfassung Es wird festgestellt, dass die Aktivität der Monoaminooxidase bei CiliatenTetrahymena pyriformis in der exponentialen Wachstumphase abnimmt und in der stationären Phase zunimmt. In der synchronisierten Zellpopulation verringert sich die Enzymaktivität in beiden Phasen der Zellteilung und der DNS-Synthese.     

Multiplicity of monoamine oxidase in chick brain

Summary The substrate- and inhibitor-related characteristics of monoamine oxidase (MAO) were studied on chick brain mitochondria. It was found that neither 5-hydroxytryptamine nor -phenylethylamine is the specific substrate for type A and type B MAO in chick brain.     

Liver monoamine oxidase in normal and regeneratingDiemictylus viridescens

Résumé L'oxydase monoamine se trouve sous une forme active dans le foie d'un urodèle adulte capable d'activité normale et régénératrice. Au cours des deux premières heures qui suivent l'amputation d'un membre antérieur, on peut noter une augmentation appréciable de l'activité de l'oxydase monoamine. Cette augmentation indique que la tension physiologique produite par l'amputation rend actifs dans le foie les précurseurs de l'oxydase monoamine qui peuvent, à leur tour, stimuler un métabolisme plus rapide et augmenter la quantité des catécholamines qui circulent.     

Inhibition of rat testicular monoamine oxidase activity after 250 R of whole-body X-irradiation

Résumé Chez le rat l'activité de l'oxydase testiculaire monoaminée est augmentée d'une manière significative 7 à 10 jours après une irradiation-X de 250 R du corps entier. Elle s'est abaissée au-dessous de la valeur du contrôle pendant les 153 jours qui suivirent le traitement.

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This research was sponsored by Utah State University Research Project U-300, and U.S. Atomic Energy Commission Grant No. AT(11-1)-1602.     

Monoamine oxidase activity in tissues of spontaneously hypertensive rats

Summary Monoamine oxidase (MAO) activity was assayed both in central and peripheral blood vessels of spontaneously hypertensive rats (SHR) and age-matched normotensive Wistar Kyoto rats (WKR). The activity of MAO in the brain and peripheral vasculature was essentially the same in both SHR and WKR. It can therefore be concluded that central and peripheral vascular MAO activity is not altered in the genetically hypertensive animals.     

Occurrence of mitochondrial monoamine oxidase in human semen

Summary Mitochondrial monoamine oxidase (MAO) was found in human semen, showing its K_m and V_max values of 91.7 M and 290 pmoles/mg of protein/60 min, respectively, with kynuramine as substrate. A major part of the activity was due to type A MAO.     

Multiple forms of monoamine oxidase in developing Xenopus

Zusammenfassung Das Isoenzymmuster der Monoaminoxidase verändert sich während der frühen Entwicklung der Larven vonXenopus laevis. Die Anzahl elektrophoretischer Banden verkleinert sich während der Entwicklung von vier auf eine.

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The author was supported by a grant from the Cleveland State University Faculty Research Committee. The author would like to express his thanks toJohn Y. Pun the president of Bionix (El Cerrito, California) for the use of the apparatus.