3-Hydroxy-3-methylglutaric acid and experimental atherosclerosis in rats

Summary In rats 3-hydroxy-3-methylglutaric acid effectively counteracts the lipemic and atherosclerotic response of massive doses of vitamin D₂. It regressed the formation of atheromatous arterial lesions. Furthermore the significant decrease in serum -lipoprotein levels on HMG treatment could be due to decrease in VLDL triglyceride and cholesterol levels.Acknowledgments. The authors are indebted to Dr.W. Drell, President, Calbiochem, San Diego, California, USA, for generous gift of HMG and Lady Tata Memorial Trust, India, for providing financial assistance to one of us (S.Y.K.Y.).     

3-Hydroxy-3-methylglutaric acid and triton-induced hyperlipidemia in rats.

3-Hydroxy-3-methylglutaric acid (HMG) significantly decreased cholesterol, triglyceride and phospholipid levels in whole serum, serum beta-lipoproteins and liver of Triton-induced hyperlipidemic rats. Therapeutically 50 mg HMG/kg is equivalent to 200 mg nicotinic acid/kg in lowering all these lipid parameters. HMG may exert its hypolipidemic effect through inhibition of lipoprotein synthesis.     

Hormonal rupture of larval diapause in the tickRhipicephalus sanguineus (Lat.)

Zusammenfassung Die Diapause von Larven der ZeckeRhipicephalus sanguineus (Lat.) wird durch- and-Ecdyson beendet.

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We would like to thank Dr.J. B. Siddal for generously providing-ecdysone, Dr.T. Takemoto for-ecdysone and Dr.N. Krishnan for the juvenile hormone analogue,trans, trans-10, 11-epoxy faresenic acid methyl ester.     

7α-hydroxylation of dehydroepiandrosterone in human testis and epididymis in vitro

Zusammenfassung Zerhackte menschliche Hoden und Epididymis wurden mit Dehydroepiandrosteron ohne Kofaktoren bebrütet und es wurden unter anderem 7-und 7-Hydroxydehydroepiandrosteron und 5-Androsten-3, 7, 17-triol charakterisiert. Die Ausbeute an 7-hydroxylierten Metaboliten war fast gleich in Hoden und Epididymis.

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The authors wish to thank Mr.J. Novák for his excellent technical assistance. We are indebted to Dr.J. E. Jirásek for generous performance of histological control of tissue and to Dr.S. Röhling for his kind pernission of radioactivity measurements.     

Aryl and aniline hydroxylases in rat nuclear membranes after pretreatment with pregnenolone 16α-carbonitrile,phenobarbital and methylcholanthrene

Résumé L'aryl hydrocarbure hydroxylase nucléaire répond seulement au méthylcholanthrène tandis que le phénobarbital et la prégnénolone 16-carbonitril ne l'affectent pas. Les trois substances n'induisent pas l'aniline hydroxylase nucléaire. Cependant elles sont des puissants inducteurs de l'aryl et l'aniline hydroxylase microsomiale.

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We thank Dr.H. Gelboin for the 3-hydroxybenzo(a)pyrene, Dr.J. Babcock for pregnenolone 16-carbonitrile, and Dr.M. Bornens for his helpful discussions.     

Serotoninantagonismus an der Placenta

Summary The placentae of 17 to 19 days pregnant mice respond to subcutaneous serotonin (15 mg/kg) with vascular changes which lead to the death of the fetuses in 3–4 h. Pretreatment of the females withd-lysergic acid derivatives preserves the life of the young. Thus, LSD showed an ED₅₀ of only 30 g/kg, while UML (Deseril®) gave an ED₅₀ of 3.7 g/kg. PML takes an intermediate position. At a 50% efficiency level, UML (Deseril®) antagonises the effect of a 4000 times higher dose of serotonin.     

Laktationshemmende Wirkung von N-[d-6-Methyl-8-isoergolin-I-yl]-N′, N′-diäthylharnstoff (VÚFB-6638)

Summary The inhibiting effect of orally administered N-[d-6-methyl-8-isoergolin-I-yl], N, N-diethylurea (VÚFB-6638) on the production of milk was found in rats. The inhibition of lactation was ascertained through the observation of the daily weightgains of the suckled puppies (ED₅₀=0.112 mg/kg/day) and through the observation of the presence of milk in the stomach of these puppies, as seen through their abdomen wall (0.084 mg/kg/day). This inhibition could be abolished with exogenous prolactin, which gives evidence that the drug studied acts via the endocrine system.

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Für die technische Assistenz danken wir FrauM. Kommersová und FrauV. Maitová.     

Long term toxicity studies with endotoxoid in monkeys

Zusammenfassung Vor dem Hintergrund der vielfältigen Endotoxoidwirkung wurde diese Substanz in chronischen Toxizitätsstudien beiMacaca mulatta geprüft. Endotoxoid wurdeMacaca mulatta in einer Dosierung von jeweils 100/kg in insgesamt 51 Injektionen innerhalb von 12 Wochen injiziert. Dabei zeigte sich, dass diese Substanz keinen Einfluss auf die geprüften klinischchemischen Parameter hatte und bei makroskopischer und histologischer Untersuchung keine Veränderungen auftraten.

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Kindly supported by a grant from the Deutsche Forschungsgemeinschaft to Dr.Fritsch.     

Hoplonemertine worms—a new source of pyridine neurotoxins

Summary Two pyridine bases were isolated from the marine hoplonemertineAmphiporus angulatus (Fabricius) and identified by mass and PMR-spectroscopy as 2,3-bipyridyl and 3,2; 3,2; 4,3'-tetrapyridyl (Nemertelline). Nemertelline, the first tetrapyridyl natural product to be reported, shows a structural resemblance to the tobacco constituent nicotelline. The crustacean toxicity of 2,3-bipyridyl is very similar to that of nicotine, but its mammalian toxicity is negligible.We thank DoctorsN. Meinkoth andN. Riser for collecting specimens, Dr.F. Kuffner for providing the nicotelline sample, Dr.C. Westerman for recording initial PMR-spectra, and Dr.R. King for furnishing the computer simulation program and recording the high resolution mass spectra, and Mr.J. Babashak for use of the Kontes densitometer. This research was supported by an NIH-GRS grant and by the Veterans Administration (No. MRIS-9416).     

Differential effects of ethanol on prostaglandin responses of arterial and venous smooth muscle

Summary The present results, using isolated rat aortic strips and portal vein segments, demonstrate that ethanol, depending upon concentration, can either enhance or attenuate the contractile actions of PGF₂ on at least 2 different types of vascular smooth muscle. At the very least, the present findings question the use of ethanol as a solvent when investigating the contractile actions of PG molecules on smooth muscles.Supported by NIH grant No. HL-18015 and NIMH grant No. MH-26236. The authors are indebted to Dr.John E. Pike and Dr.John Babcock of the Upjohn Company for generously providing us with the PGF₂ used in this study.     

Subcellular distribution of catecholamines and enzymes in human neuroblastoma

Résumé Dans 18 cas de neuroblastome humain la noradrénaline (NA) et la dopamine--hydroxylase présentent des profils de distribution intracellulaire identiques, suggérant un stockage dans la même particule. Le contenu en NA de ces particules n'est pas inférieur à celui des particules du nerf splénique; on peut en conclure qu'un stockage défectueux de NA dans les cas de neuroblastome est peu probable.

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The authors are grateful to Prof.F. Derom (Surgical Clinic, University of Ghent Medical School), Prof.R. Eeckels and Prof.E. Eggermont (Paediatric Clinic, University of Leuven Medical School), Prof.A. Lacquet and Prof.J. Gruwez (Surgical Clinic, University of Leuven Medical School), Dr.G. Delalieux, Dr.F. Delange, Dr.P. De Mol, Dr.R. Denis, Dr.R. Maurus and Dr.J. Otten (Paediatric Clinic, University of Brussels Medical School) and Dr.W. Mattheiem (Surgical Clinic, Jules Bordet Institute, Brussels) for making the tumors available to them.     

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.     

The effect of the ergoline derivative VUFB-6683 on the adenohypophysial prolactin concentration in rats

Zusammenfassung Mit Hilfe vond-6-Methyl-8-ergolin-I-ylacetamid-Tartarat, VUFB-6683 wurde bei säugenden Ratten das Gewicht und der Prolaktinspiegel der Adenohypophyse herabgesetzt und die Laktation gehemmt.

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The authors are indebted to Dr.I. J. Skála, Dr.J. Hondlík, Mrs.V. Maitová and Mrs.J. Emanuelová for technical assistance; and to Dr.I. Mikulá for his aid in designing the study.     

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.     

Circadian rhythm of progesterone secretion during pseudogestation in the rat

Résumé Par des canulations toutes les 6 heures chez des rattes le 7ème jour de la pseudogestation nous avons pu mettre en évidence un pic de progestérone entre 09.00 et 11.00. Sur la base de nos résultats (progestérone, 20 -OH-progestérone, poids des ovaires et corps jaune) et de la publication deFreeman etNeill ³ nous discutons le rôle de la LTH comme régulation possible de ce phénomène.

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Acknowledgements. The authors wish to express their appreciation to Dr.L. Schenkel-Hulliger for her helpful advice during this project.     

Fluorescence of blood cells of the tunicatesPhallusia mamillata andCiona intestinalis

Zusammenfassung Von den Blutzellen derPhallusia mamillata Cuvier zeigen nur die stark vakuolisierten (compartment cells) im UV-Licht eine stabile blaue Fluoreszenz ( _max =5200 und 4600 Å). Sie ist in den Zellgranula lokalisiert. Bei den Blutzellen vonCiona intestinalis L. tritt dagegen eine gelbe Fluoreszenz ( _max = 5900, 5200 und 4600 Å) auf, die nur von den Vanadocyten ausgeht. Diese Fluoreszenz, welche auch von den Testazellen der Oocyten gegeben wird, geht innerhalb einiger Minuten in die blaue Fluoreszenz über.

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This work has been carried out in the Stazione Zoologica, Napoli (director Dr.P. Dohrn) and in the Istituto di Biologia Generale e Genetica della Università di Napoli (director Prof. Dr.B. de Lerma). —M. de Vincentiis wishes to thank Dr,P. Dohrn for placing at his disposal a working place of the Consiglio Nazionale delle Ricerche, Roma. —W. Rüdiger thanks sincerely the Deutsche Forschungsgemeinschaft, Bad Godesberg, for providing grants, and Prof. Dr.H.-J. Bielig for his interest.     

Selective blockade by mephentermine of reserpine-induced serotonin depletion

Zusammenfassung Die kombinierte i.v. Verabreichung von Reserpin (1 mg/kg) und Mephentermin (1 mg/kg) bewirkte Erregung in Kaninchen. Diese Erregung ist verbunden mit einem Verlust an Noradrenalin (NE) im Gehirn, nicht jedoch mit einem Verlust an Serotonin (5-HT). Aus den Ergebnissen lässt sich schliessen, dass die beobachtete Erregung von einem momentanen Ungleichgewicht zwischen NE und 5-HT im Gehirn herrührt.

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This study is supported in part by Career Development Award No. K3 NB 15279-09 and Grant No. MH 11189 from the National Institutes of Health, U.S.P.H.S. The authors wish to thank Dr.A. J. Plummer of CIBA Pharmaceutical Company for supplying the reserpine phosphate and Dr.R. J. Bower of Wyeth Laboratories for the mephentermine used in this study.     

Some characteristics of end-plate potentials after partial blockade by α-bungarotoxin inRana temporaria

Zusammenfassung Nach Behandlung des Sartoriusmuskels von Rana temporaria mit Bu TX wurden die Endplattenpotentiale durch Tubocurarin und Atropin mit unveränderter Wirksamkeit blockiert. Bungarotoxin stabilisiert das Umkehrpotential der Endplatte, welches nachher durch eine Verminderung der äusseren Konzentration von K⁺ oder durch Atropin nicht mehr verändert werden kann.

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The autors are greatly indebted to Dr.D. Eaker from Uppsala University for sending them the polypeptide N. 3 (Naja toxin) and Dr.Yu. Ovchinnikov from Academy of Sciences USSR for the oportunity of working with -bungarotoxin.     

Identification of a major cytokinin in coconut milk

A major cytokinin found in coconut milk was isolted by using the tobacco callus growth-promoting assay as a guide during purification. The structure of the factor was determined to be 14-O-{3-O-[-d-galactopyranosyl-(12)--d--galactopyranosyl-(13)--L-arabinofuranosyl]-4-O-(-L-arabinofuranosyl)--d-galactopyranosyl}-trans-zeatin riboside [G₃A₂-ZR] by various NMR techniques, including heteronuclear multiple bond connectivity by 2D multiple quantum NMR (HMBC), as well as mass spectroscopy and sugar analysis. The optimum concentration of G₃A₂-ZR for cytokinin activity in the tobacco callus assay was estimated to be 5×10^–6 M, so that G₃A₂-ZR is one order of magnitude more potent than 1,3-diphenylurea and one order less potent than zeatin riboside. At least 20% of the cytokinin activity of coconut milk could be attributed to G₃A₂-ZR.