Impaired proximal tubular transport functions in anaesthetized splanchnicotomized dogs

Summary The maximal tubular transport of inorganic phosphate,d-glucose and para-aminohippuric acid, respectively, was depressed on the denervated side in unilaterally splanchnicotomized, anaesthetized dogs. It is concluded that renal sympathetic activity might in general regulate proximal tubular transport functions.The authors are indebted to Mrs V. Vajda, Mr A. Karai, Mrs K. Kéry, Mrs B. Asztalos, Mr S. Szécsi and Mr J. Vártok for their valuable technical assistance.     

Effects of calcium-EGTA buffers on active calcium transport in inside-out red cell membrane vesicles

Summary In inside-out red cell membrane vesicles, the free calcium concentration half-maximally stimulating active calcium uptake is about 2 orders of magnitude smaller in a calcium-EGTA buffer than in media containing unbuffered calcium. In calcium-EGTA buffer, the maximum rate of calcium uptake is determined by the total calcium concentration present. A possible model for explaining these findings is presented.Acknowledgments. This work was supported by the Scientific Research Council, Ministry of Health, Hungary (6-03-0306-01-1/Gá). We thank for the valuable comments of Dr Ilma Szász and for the skilful technical assistance of Mrs M. Sarkadi.     

An improved method of transplantation on chicken chorioallantoic membrane (CAM)

Summary An improved method for grafting on the chicken CAM is described and compared with other CAM grafting methods.The author is very grateful to Prof. L. Vakaet, RUCA Antwerpen, to Dr and Mrs M. Mareel, RUG Gent, for their valuable suggestions and to Mrs S. De Wolf-Van Rompaey for her excellent technical assistance. The author is also indebted to Mr F. De Bruyn for making the drawing.     

Receptors for polymerized albumin on liver cells

Summary By the use of rabbit polymerized albumin labelled with fluorescein isothiocyanate, or coated on sheep red blood cells, specific receptors on rabbit liver cells were demonstrated. The possible biological role of these receptors is discussed.We thank Prof. I. Moraru for discussions, Dr A. Sulica for criticism and Mrs Agavni Slughian and Mrs Mariana Caralicea for excellent technical assistance.     

Determination of uric acid and hematin in a single sample of excreta from blood-fed insects

Summary Uric acid and hematin, the principle excretory products in blood-fed mosquitoes can be determined quantitatively in the presence of each other in fecal material from individual females.The investigation was supported by a research grant from the Swiss National Science Foundation. The assistance of Mrs E. Csibi and Mrs U. Briegel is gratefully, acknowledged.     

Reappearance of HCG-receptors in immature rat ovary after HCG-treatment is not due to receptor synthesis

Summary In 24-day-old rats the reappearance of ovarian HCG-receptors after the injection of 200 IU HCG is independent of protein synthesis. The reutilization of occupied receptors in immature female rats is due to dissociation of the receptor-hormone complex.This work was supported in part by the Deutsche Forschungsgemeinschaft (SFB 46). Purified HCG was a gift of Schering AG, Berlin West. We thank Mrs Margarete Lindig and Mrs Rita Rudolph for assistance and Mr A. Schlegel for radioimmunological determinations.     

Inhibition of Ca2+-induced noradrenaline release from central noradrenergic neurons by morphine

Summary Morphine inhibited the noradrenaline release from slices of rat brain cortex induced by introduction of Ca²⁺ ions after superfusion with Ca²⁺-free, K⁺-rich solution. The degree of inhibition was inversely related to the Ca²⁺ concentration used for stimulation.Acknowledgment. We thank Mrs G. Thielecke and Miss G. Werthmann for technical assistance.     

Adrenalectomy,ovarian HCG-binding and the onset of female puberty in the rat

Summary The delay of puberty onset in female rats adrenalectomized before the 25th day of age is due neither to changes in the number of ovarian HCG-receptors nor to an altered hormone affinity of these receptors. It is assumed that glucocorticoids act on an intracellular level, in the ovarian cells, possibly by alterations of cyclic AMP-dependent phosphodiesterase activity.This work was supported in part by the Deutsche Forschungsgemeinschaft (SFB 46). Purified HCG was a gift of Schering AG, Berlin-West. We thank Mrs Margarete Lindig for assistance and Mrs Ursula Frigewski for secretarial help.     

Cold stress induced changes in the uptake and distribution of radiolabelled magnesium in the brain and pituitary of the rat

Résumé L'imposition de conditions hypothermiques augmente l'incorporation de²⁸Mg dans le cerveau et la glande pituitaire du rat.

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Research for this paper was supported by NSF No. GB 27740 X. The authors are grateful for the technical assistance of Mrs.M. Turner, Mrs.E. Rovner and Mrs. L. Macko.     

Chemical studies on the silver staining of nucleoli

Summary The uptake of Ag-ions by isolated nucleoli of rat liver cells was studied. Nucleolar proteins separated by electrophoresis were examined for selective silver-staining. A mechanism for a preferential Ag-staining of the nucleoli is discussed.We thank Mrs L. Schwinn for her valuable technical assistance, and Mrs K. Jain for presenting us DNA. We would like to thank the Department of Biology V for making possible the measurements with the atomic absorption spectrophotometer. This work was supported by the Deutsche Forschungsgemeinschaft.     

The number of parallel fibre-Purkinje dendrite synapses. A morphometric evaluation

Summary Quantitative parameters concerning synapses were studied in the cerebellar molecular layer of 4 cats using ultrastructural morphometric methods. The number of parallel fibre-Purkinje dendrite synapses was estimated to be about 200,000.This study was granted by I.N.I.C. (Centro de Morfologia Experimental—MbP₁ e Centro de Anatomia Patológica e Oncologia-MbP₃).The authors thank Mrs M.L. Brito, Mrs M.A. Nascimento, Mrs M.G. Rodrigues and Mr L.B. Nunes for their technical assistance.     

Participation of microtubules and microfilaments in the transcellular biliary secretion of immunoglobulin A in primary cultures of rat hepatocytes

Summary The biliary secretion of immunoglobulin A (IgA) in primary hepatocyte cultures was investigated by means of immunofluorescence. The characteristic accumulation of IgA in visible bile canaliculi was found to be strongly inhibited by vinblastine and colchicine or by cytochalasin B, but its surface binding was not.The author thanks Prof. Dr D. Mecke for his support and encouragement. The excellent technical assistance of Mrs M. Behringer and Mrs A. Schneck is gratefully acknowledged. The author is grateful to the BIOTEST Serum Institut (Frankfurt) for the kind gift of human IgA. This work was supported by the Deutsche Forschungsgemeinschaft.     

Purification of a nuclease from human serum

Summary The purification procedure for a nuclease from human serum is described. It includes ammonium sulfate precipitation, chromatography on DEAE-Sephadex and on Sephacryl-S 200, and preparative electrophoresis. The enzyme, purified about 2000-fold, is homogeneous in a sodium dodecyl sulfate electrophoretic system, where it has a mol. wt of 78,000. The pH optimum lies around pH 6.5; it is a sugar-nonspecific endonuclease.Acknowledgment. This work has been supported by a research grant from Stiftung Volkswagenwerk through the Akademie der Wissenschaften und der Literatur, Mainz. We thank Mrs R. Nehrbass and Mrs C. Wolpert for technical assistance.     

Dietary utilization of aliphatic alcohols byDrosophila

Summary Metabolic utilization was measured by the increase in life duration of adults receiving a low concentration of alcohol as the sole energy source. Flies were able to use primary alcohols as food in the following order: butanol > ethanol > propanol. Methanol and secondary alcohols were not metabolized. These results cannot be explained by considering only the specific activity of alcohol dehydrogenase upon these substrates.Acknowledgments. We thank Mrs De Scheemaeker-Louis for doing the electrophoretic analysis.     

Autophagy in mouse hepatocytes induced by lysine acetylsalicylate

Summary I.v. administration of lysine acetylsalicylate inces autophagy in mouse liver cells. Single and multiple membrane-bounded vacuoles were found. The latter seems to be an unusual morphological form of the sequestration process. These findings could express a transitory sublethal liver cell injury induced by the drug.Acknowledgments. The authors are indebted to Mrs M. T. Correia and to Mrs M. E. Pereira for technical assistance.     

Effects of 1-alkyl-1,2,3,4-tetrahydrocarbazole-1-ethanamines and related compounds,potential antidepressants,on biogenic amine uptake mechanisms

Summary A new series of compounds structurally related to the potential antidepressant tandamine, i.e., the 1-alkyl-1,2,3,4-tetrahydrocarbazole-1-ethanamines, inhibit the noradrenaline uptake mechanism and are relatively ineffective in inhibiting the serotonin uptake mechanism in vivo. The potency of the most effective compound (9-ethyl-N,N, 1-trimethyl-1,2,3,4-tetrahydrocarbazole is similar to that of desimipramine and is of potential use in the treatment of endogenously depressed patients.The authors acknowledge the technical assistance of Mrs J. Farnsworth, Mrs B. Gut and Mr J. Lacasse.     

Suramin stimulates renal growth in the rat

Summary Suramin given to rats in a single high dose (20 mg/100 g i.v.) stimulated renal growth. Maximum changes are taking place after 6–9 days of treatment.Suramin (Bayer 205) was generously provided by bayer (Leverkusen, Federal Republic of Germany).The authors thank Miss J. Telegdy and Mrs I. Harmos for technical assistance and Mrs M. Herczeg for the preparation of the sections.     

Liver enzyme induction by the anion exchanger resin,Dowex 1×2, in the rat

Summary Peroral treatment of rats with the anion exchanger resin, Dowex 1×2, for 8 days leads to liver enlargement and increase of alkaline and acid phosphatases, glucose-6-phosphate dehydrogenase, malic enzyme, catalase, and the enzymes of microsomal drug metabolism in the liver. The sequestration of bile acids by this treatment mimics the biochemical effects of clofibrate- and phenobarbital-like drugs in the liver.Acknowledgment. The authors want to thank Mrs Fey, Mrs Kremer and Mr Weinrauch for their skilful technical assistance.     

X-irradiation of mice in early fetal period influences dose-dependently sex ratio of offspring until weaning

Summary Fractionated X-irradiation of mouse fetuses on gestation days 11–13 resulted in a significantly increased postnatal mortality of female litters. This occurred only at 3×110 rad, which was the threshold for the formation of typical neuroepithelial, rosette-like malformations.We are greatly indebted for the technical assistance of Miss C. Gutmann, Mrs I. Hempfling and Mrs K. Pfaff.     

Effect of ambient cold on urine concentration by the intact and denervated dog kidney

Summary In dogs transferred from room temperature to a low temperature of 1±(SD) 3.5°C, the plasma norepinephrine (NE) level increased significantly. Urine concentration decreased in the cold, in the intact and similarly in the chronically denervated kidney. After return to a warm environment urine concentration improved in both kidneys while plasma NE remained elevated. The data speak against an essential role of the renal nerves in the adaptation of renal function to ambient cold.Acknowledgments. We are greatly indebted to Dr J. Kurkus and Dr R. Gellert who performed the operations of surgical bladder division, and to Mrs W. Radziszewska for determination of plasma norepinephrine. The study was supported within the national research problem No. 10.4.