On the role of the decreased renal vascular resistance in the mechanism of volume natriuresis

Summary Acute hypohysectomy (AH) prevented the increase of the cardiac output, renal cortical blood flow (e.g. the decrease of the renal vascular resistance) and renal sodium excretion during the ECFV expansion. The non-occurrence of natriuresis in AH rats is suggested as being partly in causal relation to the inability to decrease the renal vascular resistance and thus to increase the peritubular hydrostatic pressure.Expert technical assistance of Mrs.E. Blaková, J. Kyselicová and Mr.. Kaloai is sincerely acknowledged.     

Neurohypophyseal origin of a humoral factor restoring volume natriuresis in acutely hypophysectomized rats

Zusammenfassung Es wird gezeigt, dass die Natriumund Wasserausscheidung hypophysektomierter Ratten durch ein Hypophysenhinterlappenextrakt korrigiert werden kann. Es handelt sich dabei nicht um ADH und das natriuretische Prinzip scheint auch vom Oxytozin verschieden zu sein.

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The present results and conclusions were discussed in detail by one of the authors (B. L.) in his Purkynje Lecture on Interaction of hormonal and non-hormonal mechanisms of the body fluids volume regulation at the XIXth Meeting of the Czechoslovak Physiological Society, held in Prague on January 26–28, 1972.

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Acknowledgments. We wish to thank Mrs.E. Blaková for her skilled technical assistance.     

The effect of pressure changes on esterification of cholesterol and hydrolysis of cholesterol esters in rat aorta and serum

Zusammenfassung Experimente in vitro zeigen, dass unter Überdruck von 200 mm Hg die Hydrolyse von Cholesteropalmitat in den Aorten und im Blutserum von Ratten gehemmt wird: Die Esterifikation von Cholesterin, in Aorten ebenfalls erniedrigt, zeigt im Serum einen deutlichen Anstieg.

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The skillful technical asistance of Mrs.J. Malíková andJ. Straková is gratefully acknowledged.     

On the role of antidiuretic hormone in volume natriuresis and polyuria in rats

Zusammenfassung An Ratten wird gezeigt, dass eine ADH-Infusion in niedriger Dosierung die Natriurese unter einer Belastung mit physiologischer NaCl nicht beeinflusst, während das Urinvolumen reduziert wird.

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Acknowledgement. Skilful technical assistance of Mrs.M. Blaková is sincerely appreciated.     

Phosphatases IX. Differences in sialic acid content of rat liver alkaline phosphatase isoenzymes

Zusammenfassung Die Heterogeneität der alkalischen Phosphatase in der Rattenleber wird beschrieben. Anodische und kathodische Isoenzyme unterscheiden sich unter anderem durch ihre Reaktion auf die Neuraminidase Behandlung.

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V. Volek, J. tpán, E. Beneová andF. Hemanský, Sb. lék. in print (1973).     

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.     

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.     

The effect of small doses of antidiuretic hormone on renal excretion of sodium and water in saline loaded acutely hypophysectomized rats

Summary Small doses of vasopressin (200 U min^–1 kg^–1) did not influence the loss of ability of acutely hypophysectomized rats to react by natriuresis to the extracellular fluid volume expansion with saline, inspite of restoring their arterial blood pressure to normal. It is concluded that the level of antidiuretic hormone efficient enough to concentrate urine is not a decisive factor in the homeostatic mechanism promoting the volume natriuresis.Acknowledgment. Skilful technical assistance of Mrs E. Blaková is sincerly appreciated.     

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.     

Alkaloide ausVinca minor L. Vincadin,Minovin und Vincorin

Summary The isolation and characterisation of three new alkaloids fromVinca minor L. is described: Vincadine C₂₁H₂₈N₂O₂, Minovine C₂₂H₂₈N₂O₂, and Vincorine C₂₂H₂₈N₂O₃ belonging to the indol- and dihydroindol alkaloids.

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VII. Mitteilung, VI. Mitt.: sieheJ. Mokrý I. Kompi, P. efovi, und. Bauer, Coll. Czech. Chem. Comm., im Druck.     

Thyroid hormone in serum of fetal calf and pregnant cow during the last trimester of pregnancy

Summary Considerably higher thyroxine and triiodothyronine concentrations in sera of bovine fetuses than in maternal samples were found during the last trimester of pregnancy.Acknowledgment. We wish to thank Miss.R. Fajkoová for skilled technical assistance.     

Tapetal development in the anthers ofAllium sativum L. andAllium longicuspis regel

Zusammenfassung Die Meiosis PMZ verläuft beiAllium sativum L. wie auch beiA. longicuspis Regel bis zur Bildung von einkernigen Mikrosporen normal. Dann unterbleibt die erste Pollenmitosis. Mit der postmeiotischen Pollenabortion hängt unmittelbar eine Fehlentwicklung der Tapetalschicht zusammen, die sich durch Hypertrophie manifestiert.

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The author thanks MissJ. Potomková for translating the text into English and Mrs.J. Eliáová for technical assistance.     

Chemical characterization of human urine albumin in proteinuria

Summary From the urine of a patient with proteinuria, the albumin protein component was isolated and compared with human serum albumin. By comparing the amino acid composition of the original proteins and their large cyanogen bromide fragments, peptide maps and N-terminal sequences of 33 amino acid residues, the identity of both proteins was shown.We wish to express our thanks to Mr L. Slepika and Dr A. Koent for the protein fractionation. We are indebted to Mr K. Grüner for the Edman degradation experiments, to Mrs E. Drková for amino acid analyses and Mrs A. Kulhánková for technical assistance.     

Changes in the concentration of adenohypophyseal prolactin and morphological manifestations in the adenohypophysis of lactating rats after administration of D-6-methyl-8-[β-isopropylaminoethyl] ergoline-I

Summary The four days administration of D-6-methyl-8-[-isopropylaminoethyl]ergoline-I (VÚFB-10726) to nursing rats decreases adenohypophyseal prolactin as determined with disc electrophoresis, and produces changes in the histological appearance of adenohypophyses, which indicate the inhibition of prolaction production and secretion.The authors thank Dr.I. J. Skála, Mrs.J. Boubínová, Mrs.J. Emanuelová and Mrs.V. Maitová for technical assistence.     

Synthese von 22,26-Imino-cholestan-Derivaten

Summary 3, 16-diacetoxy-5-pregnane-20-one and the analogue pregn-5-ene derivative have been converted into (22R, 25R)-22, 26-imino-5-cholestane-3, 16-diol. The configuration at C-22 and C-25 was determined by transformation into the known (22R, 25R)-5-solanidane-3-one. Application of the Ruschig method led to (25R)-22,26-imino-5-cholest-22(N)-ene-3, 16-diol.

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Solanum-Alkaloide. XVI. Mitteilung. — XV. Mitteilung:K. Schreiber undH. Ripperger, Tetrahedron Letters Nr.27, 9 (1960).     

On the host-symbiont-cycle of a leafhopper (Euscelis plebejus) endosymbiosis

Summary In the host-symbiont-cycle ofEuscelis plebejus and its bacterial symbionts each of both symbionts (a and t) appears in an infection form during the intraovarial transmission (adult female) as well as during the entrance into the mycetocytes (embryo) and in a vegetative form during the remaining time of the cycle.This work was supported in part by a grant from the Deutsche Forschungsgemeinschaft to ProfessorK. Sander, whom I thank for helpful discussions.     

1,2-Methylen-19-nor-17α-acetoxy-progesteron

Summary The syntheses and structure-determinations of 1, 22- and 1, 2-methylene-19-nor-17-acetoxy-progesterones described prove that there is no influence of the angular C₁₀-methylgroup on the steric course of theCourey-methylenations of ¹-3-keto-steroids.     

The mechanism of blood vessel permeability derangement under the influence of histamine,serotonin and bradykinin

, , , , 10^–2-10^–3M NaCN . (, ). .