Variations in cardiac noradrenaline content during sodium loading in hypertension prone and resistant rats

Summary The cardiac catecholamine content of Sabra rats and their 2 genetically derived substrains, hypertension prone and resistant rats, was studied by high pressure liquid chromatography and electrochemical detection. Both in the control period and after sodium and DOCA administration the cardiac noradrenaline level is higher in hypertension resistant rats than in Sabra rats, and also higher than in hypertension prone rats. This finding suggests that a reduction of the cardiac sympathetic nervous tone is involved in the genetic resistance to sodium.     

Effect of ions on the light-sensitive current in retinal rods

The effect of ions on the light-sensitive current of retinal rods was studied by sucking the inner segment into a tightly fitting capillary with the outer segment projecting into a flowing solution. This new method showed that the light-sensitive pathway, in which Na+ is the normal carrier of current, has an ionic selectivity different from that of other known sodium channels. Externàl calcium has a striking effect on the current, which increased about 20-fold when all calcium was removed. Reducing the sodium concentration gradient greatly prolonged the response to a flash of light, as would be expected if internal calcium blocks sodium channels and if light releases calcium which is subsequently extruded by a sodium-calcium exchange mechanism.     

The effect of lipids fromListeria monocytogenes on immune response in mice

Résumé Nos expériences ont démontré que les lipides deListeria monocytogenes ont un fort effet adjuvant aux niveaux cellulaire et humoral. Comme antigène, on a utilisé des èrythrocytes de mouton. On a déterminé le nombre de cellules de la rate produisant des anticorps ainsi que le titre de l'hémolysine d'après la méthode de l'hémolyse radiale en gélose.

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Supported by grants from Polish Academy of Science.     

Tritium analyses of groundwater from the Gort Lowland of Western Ireland

Zusammenfassung Grundwasserproben aus der Gort-Ebene (West-Irland) wurden auf Tritium-Gehalt analysiert und die Ergebnisse mit dem bereits bekannten Tritium-Einstrom dieser Gegend verglichen. Registrierungen des «World Precipitation Network» in Wien ergaben den Nachweis eines offenbar langsamen Durchflusses in das Grundwasser-Aquifer-System.

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Acknowledgments. The authors are indebted to the Nuclear Physics Division, Atomic Energy Research Establishment, Harwell (England) for tritium analyses and to Mr.B. R. Payne, Section of Isotope Hydrology, IAEA, Wien (Austria) for providing unpublished tritium data from Valentia for the period 1966 to 1971.     

Effect of ultrasonic waves on the ribonuclease activity

Résumé L'irradiation ultrasonique de racines deLens culinaris provoque une baisse de l'activité RNasique dans la zone apicale (0–5 mm). L'ultrason étant non-cavitant, cette réduction d'activité doit être causée par l'action dénaturante liée aux effets thermiques de la perturbation ultrasonique. La relativement haute viscosité cytoplasmique de la zone apicale expliquerait pourquoi celleci est la seule à être affectée.