Effect of (+)-catechin on renal and intestinal transport

Summary The ability of dog renal cortex slices to accumulate -methyl-glucoside or glycine is enhanced by the flavonoid (+)-catechin at a concentration of 3.5 mM. This stimulatory effect is apparently due to a decreased rate of efflux of either substrate. On the other hand, the uptake of p-amino-hippuric acid and N¹-methyl-nicotinamide is inhibited by (+)-catechin. The drug at the same concentration is without action on amino-acid transport by guineapig intestine in vitro.This study was supported by grants from Zyma S.A., Nyon. We are grateful to MmesH. Capt andP. Ganguillet and MlleD. Mettraux for their skilful technical assistance.     

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.     

Is the renal vasodilatation induced byβ-adrenoceptor stimulants in the dog mediated through dopamine receptor?

Summary In chloralose-anaesthetized dogs the renal vasodilator effect of isoprenaline is depressed by blockade of either dopamine or -adrenoceptors but the renal vasodilator effect of dopamine is depressed only by blockade of dopamine receptors. This suggests that the vasodilatation induced by -stimulants within the canine kidney is due in part to activation of dopamine receptors.This study was supported by the Life Insurance Medical Research Fund of Australia and New Zealand and by the Australian Kidney Foundation.We thank Mr S. Marshall for technical assistance.     

Distribution of microspheres of 15±5 μm diameter in dog kidneys

Summary The size distribution of plastic non-radioactive microspheres (MS) of 15±5 m diameter in the dog kidney was investigated. No diameter-dependent redistribution of the MS was found.Acknowledgment. We acknowledge the Fresenius Company, Homburg, Germany, for supply of Plasmasteril (HES) and the Medac Company, Hamburg, Germany, which supplied us with Fluosol 43 and part of the animals used in the experiments. Supported by the Stiftung Volkswagenwerk, grant 111702.With the technical assistance of K. Anders.     

An analysis of the distribution of the myelinated nerve fibers in the optic fascicle of a Beagle dog

Summary The composition of both optic fascicles of a Beagle dog was studied in topographically oriented, semithin transections of whole nerve stained with toluidine blue. About 165,000 myelinated fibers were present in each nerve, their maximum caliber reaching 11 m; large, less densely arranged fibers occurred especially in the dorso-temporal region.We are grateful to Dr D.C. Naylor, Mrs K. Schnider, Mr F. da Silva and Mr K. Traber for their aid.     

The effect of intraventricular thyroxine administration on body temperature in dogs at rest and during physical exercise

Summary Infusion of 1 g thyroxine into the left cerebral ventricle of the dog did not change body temperature at rest, but it caused significantly higher increases in T_re during physical exercise.     

N″-cyano-N-4-pyridyl-N′-1,2,2-trimethylpropylguanidine,monohydrate (P 1134): A new,potent vasodilator

Summary N-cyano-N-4-pyridyl-N-1,2,2-trimethylpropylguanidine, monohydrate (P 1134) is a new agent which induces a marked and sustained hypotensive response in normotensive and renal, neurogenic, and spontaneously hypertensive rats, as well as in normotensive and renal hypertensive dogs. The overall potency of this compound is 2–3 times greater than that of hydralazine. The fall of blood pressure is accompanied by an increase in heart rate and cardiac output and a decrease in total peripheral resistance. The hypotensive effect appears to be due primarily to a direct relaxant effect on vascular smooth muscle.Acknowledgment. The helpful comments and advice of Dr W.O. Godtfredsen are greatefully acknowledged.     

Necrosin und die Leukozytenphagozytose

Summary The euglobulin fraction necrosin, prepared according toMenkin from pleural exudates of dogs, strongly inhibitsin vitro bacterium phagocytosis by leucocytes obtained from the abdominal cavity of rats. Depending on the concentration, the average effect amounts to 18–35%. Necrosin has a similar effect (21–38%) on the circulating leucocytes of the dog. The euglobulin fraction prepared by the same method from the serum of untreated dogs has but a slight inhibitory effect on leucocyte activity.     

In situ noradrenaline-induced stimulation of dog thyrotrophic secretion

Summary Anterior pituitary microinfusions of noradrenaline in the dog causes a significant release of TSH while adrenaline and dopamine do not.This study was supported by Grant No. S1-049 from the Consejo Nacional de Investigaciones Cientificas y Tecnológicas, Grant No. 281 from the Consejo de Desorrallo Cientifico y Humanístico, Central University of Venezuela, and Fundación José María Vargas.     

Effect of isoprenaline on dopamine receptors in the rabbit isolated renal artery

Summary The relaxant effects of isoprenaline on rabbit isolated renal artery and aorta were compared. The results suggest that although isoprenaline acts on -adrenoceptors in the aorta it stimulates dopamine receptors in the renal artery.     

Effect of dihydroergocristine infusion on tolbutamide-induced insulin secretion in man

Summary The insulinemic response to 1 g of tolbutamide i.v. is greatly enhanced (+145%) after a 60-min infusion of the -lytic dihydrogenated ergot alkaloid, dihydroergocristine (83.3 m/min, corresponding to a total dose of 5 mg) in 7 healthy subjects. No differences are observed in the glycemic responses.Acknowledgment. The authors are grateful to Mr Franco Della Sala, M.D., for his skillful technical assistance.     

Restriction enzyme studies on human highly repeated DNAs

Summary Various restriction enzymes digest human highly repeated homogeneous DNA to discrete fragments, some of which are present in the male and absent in the female. The male specific 2.4 kilobase HaeIII fragment corresponds to human male satellite DNA IV.This work was supported by grant No. 80.01523.96 from the Progetto finalizzato: Controllo della Crescita Neoplastica of C.N.R. (Rome). We are grateeful to Ms Donatella Guinzoni-Confortini for technical assistance.     

Zur Frage der glomerulären Permeation höhermolekularer Proteine

Summary Haptoglobin and isoagglutinin were found in the urine of diabetic patients, and their renal excretion was higher in patients with diabetic angiopathy. It is concluded from these results (the biological activity of the two polypeptides in urine was intact) that the mechanism of proteinuria can perhaps be explained only by an extension of pores of the renal glomerular filter.     

Irreversible shock in rats after injection of microspheres into the renal artery

Summary After injection of microspheres into both renal arteries of rats, an irreversible shock syndrome develops, resulting in death within 4–12 h. Ligation of both renal pedicles after injection of microspheres prevents the shock. It is presumed that kininogenases released from the kidneys participate in the pathogenesis of the shock syndrome.These studies were supported in part by the Deutsche Forschungsgemeinschaft within the SFB 90, Cardiovasculäres System.     

The ‘Spitzenkörper’, centre of the reducing power in the growing hyphal apices of two septomycetous fungi

Summary Redox dyes, such as methylene blue and neutral red, are stably reduced to their leucobase in the Spritzenkörper of the growing hyphal tips ofNeurospora crassa andMonilia fructigena.We acknowledge the support of the Fonds National Suisse de la Recherche Scientifique and thank both Mrs Ton-That for her electron micrograph and Miss E. Herz for her technical help.     

Regulation of rat renal (Na++K+)-adenosine triphosphatase mRNA levels by corticosterone

We investigated the mechanisms for glucocorticoid regulation of rat renal NaK-ATPase activity. Our findings suggest that the magnitudes of corticosterone-induced increases in ₁ mRNA and ₁ mRNA levels are similar in the kidney of the adult adrenalectomized rats. The results also suggest that corticosterone restores NaK-ATPase activity in adrenalectomized rats prior to any enhanced sodium delivery.     

Heat shock-induced gynandromorphism in the pharaoh's ant,Monomorium pharaonis (L.)

Summary The ability of ants to reacting to sublethal high temperatures with production of gynandromorphs is reported for the first time. The abnormal forms produced in the pharaoh's ant range from ergatandromorphs to classical halfsidegynanders.Thanks are due to Drs V. Rupe (Prague), and B. Styczýnska (Warsaw) for providing the ant strains mentioned and to Mrs G. Hilzbrich for technical assistance.     

Enterohepatic cycling of O-(β-hydroxyethyl) rutosides and their biliary metabolites in the rat

Summary O-(-Hydroxyethyl)rutosides are shown to undergo reabsorption from the intestine following their secretion in bile.Acknowledgment. The authors wish to thank Mr P. B. Wood and Mr S. D. Godfrey for skilled technical assistance and Zyma, S. A., Nyon, Switzerland, for financial support.     

Polypeptides of cerebral subcellular fractions of differentially-housed mice

Summary The difference in protein of cerebral nerve-ending fractions caused by differential housing of male mice is of a quantitative nature and might reflect a change in the number of nerve-endings.This work was supported in part by Centro Nacional Ramón y Cajal (de la Seguridad Social) and Fundación Juan March and was conducted in part at the Istituto Nazionale per lo Studio e la Cura dei Tumori, Milan Italy, while Dr F. P. Conde was on a research fellowship. Thanks are due to Mr Riccardo Gelati for technical assistance and to Mr Mario Azzini for the photography.