Human plasma dopamine-β-hydroxylase: Oxygen and thermal stability

Summary There are wide individual variations in the thermal stability of human plasma dopamine--hydroxylase (DBH). Thermal stability variations have proven of value in biochemical genetic studies of many enzymes. The development of DBH thermolability depends on the exposure of plasma to oxygen. This observation may help to elucidate the biochemical basis of the genetic regulation of DBH.This work was supported in part by NIH grants HL 17487 and NS 11014.     

Erythrocyte catechol-O-methyltransferase and plasma dopamine-β-hydroxylase in human umbilical cord blood

Summary Plasma dopamine--hydroxylase enzymatic activity and immunoreactive protein levels in human umbilical cord blood are only about 2% as great as values in the blood of older subjects. Erythrocyte catechol-O-methyltransferase activity levels in umbilical cord blood are very similar to those in the blood of adult subjects.This work was supported in part by NIH grants NS 11014 and HL 17487-1. Dr Weinshilboum is an Established Investigator of the American Heart Association. We thank Luanne Wussow and the physicians and nurses of the Department of Obstetrics and Gynecology of the Mayo Clinic for their assitance with these studies.     

A radioimmunoassay for dopamine-β-hydroxylase using a glass-bound antibody

Résumé Les auteurs décrivent une méthode radioimmunologique de dosage de la DH utilisant un anticorps lié de façon covalente à des billes de verre. La technique a été appliquée à la mesure de la DH dans les surrénales et différentes régions du cerveau de buf. Les principaux avantages de cette méthode sont sa relative facilité d'emploi, sa précision et sa haute spécificité.

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This work was supported by USPHS Grants Nos. MH-02717, NS-06801 and CA-02071 and NSF Grant No. GB-27603.Acknowledgements: The authors wish to express their appreciation for the technical assistance of Susan Kadner and William P. Vann.     

Adrenal dopamine-β-hydroxylase activity: 24-hour rhythmicity and evidence for pineal control

Summary Adrenal medullary dopamine--hydroxylase activity was found in male rats to have a 24-hour rhythm, with an approximately 6-fold increase at about the time of the onset of darkness. This nocturnal rise in enzyme activity did not occur when lights were kept on, nor did it occur in animals that had been pinealectomized.Supported in part by grants from the Ford Foundation (No. 630-05050A), National Institutes of Health (No. HD-03352) and National Institute of Mental Health (No. MH-25019) USPHS.     

Elevation of plasma dopamine-β-hydroxylase activity during insulin-induced hypoglycemia in man

Résumé Nous avons étudié l'activité de la dopamine--hydroxylase du plasma humain. Elle a été remarquablement accure par l'administration de grandes quantités d'insuline. Les corrélations entre cette activité et celle des systèmes nerveux sympathiques sont également discutées.     

Dopamine-β-hydroxylase activity in stroke-prone spontaneously hypertensive rats

Summary Dopamine--hydroxylase (DBH) activity was higher in the serum, the mesenteric artery and the cerebral cortex of 4-week-old stroke-prone spontaneously hypertensive rats (SHRSP), and lower in the nucleus tractus solitarii than it was in spontaneously hypertensive rats (SHR).The authors wish to thank Prof. Masao Sano (Nagoya University) for his aid in dissecting the nucleus tractus solitarii and the locus coeruleus.     

Changes in dopamineβ-hydroxylase activity of monkey plasma with age

Summary Plasma dopamine -hydroxylase activity of Japanese monkeys (Macaca fuscata fuscata) increased with age, and the developmental changes were similar to those of human beings. However, the adult level plasma DBH activity of various monkey species was much lower than that of human beings.We thank Dr.K. Nozawa, Dr.O. Takenaka and Mr.T. Shotake (Primate Research Institute, Kyoto University) for their help in collecting monkey blood samples.     

Kinetic studies on soluble and membrane-bound dopamineβ-hydroxylase isolated from storage vesicles of heart and adrenal medulla of different species

Summary IdenticalK _m-values for soluble and membrane-bound dopamine -hydroxylase isolated from adrenal medullary vesicles of different species were obtained; the same holds true for both forms of the enzyme of heart vesicles.The excellent technical assistance of MissSabine Klemt is gratefully acknowledged.     

α- andβ-Guttiferins

Zusammenfassung Die Isolierung, Charakterisierung und antibiotischen Eigenschaften von-Guttiferin (I), C₃₃H₃₈O₈ (Smp. 113–115°), aus den Samenhülsen und vom nahe verwandten-Guttiferin (II), C₂₉H₃₆O₆ oder C_33–34H_38–40O₈ (Smp. 86–91°) (möglicherweise identisch mit-Gambogasäure), aus Gummigutt, dem harzigen Sekret vonGarcinia morella, wurden beschrieben und ihre Verwandtschaft zu Morellin und Moreollin, den beiden bekannten Pigmenten der Samenhülsen, dargelegt. Für I wurde eine Partialstruktur vorgeschlagen. Die Bildung derselben komplexen bromhaltigen Säure vom Smp. 199 bis 200° unter der Einwirkung von Natriumhypobromit auf I und II spricht ferner für deren nahe strukturelle Verwandtschaft.     

Dopamine-β-hydroxylase,adrenaline, noradrenaline and dopamine in the venous blood of adrenal gland of man: A comparison with levels in the periphery of the circulation

Summary In 10 human subjects plasma dopamine--hydroxylase activity was found in the adrenal vein blood to be as high as in the periphery of the circulation. Adrenaline concentration in the adrenal vein blood was in the mean 170 times, noradrenaline concentration 11 times and dopamine concentration little higher than levels in the periphery.This study was supported by the Deutsche Forschungsgemeinschaft.     

β-Endorphin in normozoospermic and pathologic human semen

Summary -Endorphin was estimated in normozoospermic, oligozoospermic and azoospermic human semen. The mean amount in normozoospermic specimens was 278.6±43.6 (SE) pg/ml while in the others only 191.1±25 pg/ml. Both values are significantly higher than those present in the blood.     

Completion of the natural groups of ergot alkaloids: Syntheses and pharmacological profiles ofβ-ergosine andβ-ergoptine

Summary The syntheses and pharmacological potencies of -ergosine and -ergoptine, the missing links in the natural groups of ergot peptide alkaloids are described.86th communication on ergot alkaloids.     

1β-Hydroxylation ofd-norgestrel and norethisterone byBotryodiploadi malorum

Zusammenfassung Die mikrobiologische 1-Hydroxylierung vond-Norgestrel und Norethisteron durch den MikroorganismusBotryodiplodia malorum wird beschrieben. Ausserdem wurde 11-Hydroxynorethisteron isoliert und charakterisiert.

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Acknowledgement. The authors want to express their appreciation to Dr.H. Smith for advice and encouragement through the course of this work. We wish to thank Dr.T. Chang, Dr.C. Hetzel and Mr.C. Kuhlman for obtaining and interpreting the mass spectra and Mr.B. Hormann for NMR decoupling experiments and analytical services.     

On the mineralocorticoid and hypertensogenic properties of 16β-Hydroxy-Dehydroepiandrosterone

Summary Dosages of either 1 or 2 mg daily of 16-hydroxy-dehydroepiandrosterone, given to mononephretomized, salt-loaded female rats, had no detectable effect upon saline consumption, blood pressure, kallikrein excretion or heart and kidney weight. Its alleged mineralocorticoid properties, as judged by these criteria, were not demonstrable.This study was supported by a grant No. HL 15319 from the United States Public Health Service.     

Microbiological transformations ofβ-sitosterol and stigmasterol by a soil pseudomonad

Summary Fermentation of -sitosterol by a soil pseudomonad resulted in the formation of 4-stigmasten-3-one, 4-stigmasten-3-one-6-ol and 5-stigmasten-3, 7-diol. In case of stigmasterol the metabolites isolated and characterized were 4,22-stigmastadien-3-one, 4, 22-stigmastadien-3-one-6-ol and 5,22-stigmastadien-3, 7-diol.The soil pseudomonad strain (BS-305) is maintained at 4°C on nutrient-agar slants.     

Levels ofβ-trace protein and lysozyme in human amniotic fluids

Summary The levels of -trace protein and lysozyme were estimated in amniotic fluids from normal fetuses and from fetuses with neuraltube defects. The values of these proteins in normal amniotic fluids were found to be similar to those detected in fetuses with anencephaly and spina bifida. The levels of lysozyme were shown to be correlated with gestational age.     

Antihypertensive and cardiac effects of two novelβ-adrenoceptor blocking drugs

Summary Two new-adrenoceptor blocking drugs with acute antihypertensive and positive inotropic effects are described: Compound A (2-[4-(3-tert. butylamino-2-hydroxypropoxy)phenyl]-4-trifluoromethylimidazole) and MK-761 (2-(3-tert. butylamino-2-hydroxypropoxy)-3-cyanopyridine hydrochloride). In SH rats both compounds, given orally, lowered arterial pressure and were more potent than hydralazine. The antihypertensive effect of compound A but not of MK-761 was antagonized by timolol. Both compounds had positive inotropic activity on cat heart papillary muscles; these effects were antagonized by timolol. The pretreatment of animals with reserpine greatly reduced the positive inotropic effect of MK-761 but not of compound A. The acute antihypertensive and positive inotropic effects of compound A are likely to be at least partially due to stimulation of-adrenoceptors, e.g. intrinsic sympathomimetic activity. The effects of MK-761 on the same parameters appear to be mediated by different mechanisms.     

α-andβ-activity of O-methylated derivatives of norepinephrine and epinephrine

Summary Metanephrine, iso-metanephrine, normetanephrine and isonormetanephrine were tested for - and -activity on various tissues obtained from rats, guinea-pigs and cats. It was found that methylation of the hydroxyl groups of norepinephrine or epinephrine in either the 3-or 4-position markedly reduces or abolishes -and -activity with the exception of the nictitating membrane of the cat. This receptor seems to show a tissue difference.Acknowledgment. W. H. V. would like to thank the Federal Republik of Germany for the U. S. Senior Scientist Award which enabled him to work at the Department of Pharmacology, University of Mainz, and to conduct part of this work. W. H. V. would also like to thank Prof. Dr E. Muscholl, Mainz, for his hospitality, help and advice during this stay.     

Alterations ofβ-adrenoceptor-density and cAMP-synthesis in rat-erythrocytes after stress erythropoiesis

Summary During the maturation of red blood cells from rats after stress erythropoiesis, adenyl cyclase activity and -adrenoceptor density (pmoles/mg protein) decrease at distinctly different rates suggesting a different turnover of these membrane units.Acknowledgments. This work was supported by the Deutsche Forschungsgemeinschaft. The skillful technical assistance of Mrs I. Groth and Mrs C. Kiele is gratefully acknowledged. The liquid scintillation spectrometer was a gift from the Dr Robert-Pfleger-Stiftung.