Interferon-dependent induction of mRNA activity for (2'-5')oligo-isoadenylate synthetase

At least three different enzymes involved in the regulation of protein synthesis are induced in a variety of cells by interferon (IFN). Sensitive assays for these enzymes have been developed and used to establish the specificity, dose dependence and time course of their induction by IFN. One of these enzymes, the oligo-isoadenylate synthetase E, whose product (2'-5')pppApApA activates the latent ribonuclease F, is increased over 50-fold after IFN treatment. We describe here the assay for an mRNA from IFN-treated mouse L cells, that produces oligo-isoadenylate synthetase activity when injected into Xenopus oocytes. This mRNA is found in the cells only after exposure to IFN. The mRNA increases in mouse L cells with the same time course as the enzyme activity itself. In particular, there is a 3-h lag period between IFN addition and the onset of enzyme and mRNA accumulation. Using anti-IFN antibodies, we show that during this lag period the continued interaction of IFN with the cells is necessary for the full induction of the oligo-isoadenylate synthetase.     

Effect of lesions of the locus coeruleus complex on the circadian rhythm of plasma corticosterone in the mouse

Summary An apparently transient elevation of basal morning (08.00 h) plasma corticosterone levels in male mice was found 48 h after bilateral electrolytic lesions of the brainstem locus coeruleus complex but was not observed 6 weeks after lesioning.Supported by Alfred P. Sloan Foundation research fellowships awarded to W.G. Luttge and S.F. Zornetzer.     

125I-Insulin is preferentially internalized in regions of the hepatocytes rich in lysosomal and Golgi structures

Summary ¹²⁵I-Insulin initially localizes to the plasma membrane of isolated rat hepatocytes but is subsequently internalized and preferentially associates with lysosomal structures. In the present study, we show that this preferential association to lysosomes occurs in regions of the cell rich in lysosomal and Golgi structures.This work was performed while Dr Gorden was visiting professor of the Institute of Histology and Embryology, University of Geneva, Geneva, Switzerland.This work was supported by grant No. 3.120.77 from Swiss National Science Foundation. We thank M.M. Sidler-Ansermet, O. Jerotic and N. Maalaoui for their valuable help.     

The effects of oxamate on the contractility of isolated rat atria

Zusammenfassung Oxamat, das die Lactat-Dehydrogenase hemmt, erniedrigt die Kontraktionsfähigkeit des Vorhofs mit und ohne Anwesenheit von Glucose im Medium und bei Hinzufügung von 2-DG oder Atropin. Hohe Konzentration von Pyruvat erhöht die Depression von Oxamat auf den Vorhof im Glucose-Milieu. Oxamat sensibilisiert das Gewebe für funktionellen Abbau durch Glycolyse.

---

---

This research was supported by grants No. 1441 and No. HE-994801 from Consejo Nacional de Investigaciones de la República Argentina, and from the National Institute of Health, respectively.

---

Research Fellow from the Consejo Nacional de Investigaciones de la República Argentina.

---

Established Investigator from the Consejo Nacional de Investigaciones de la República Argentina.     

Experiments on mitochondrial swelling in vivo

Riassunto E stato provato l'effetto sui mitocondri in vivo dei seguenti composti che producono rigonfiamento dei mitocondri isolati in vitro:l-cistina,l-cisteina, glutatione, L-ascorbato,l-tiroxina,l-3, 5, 3-triiodotironina, fosfato e Ca⁺⁺. Solo il Ca⁺⁺ ha provocato un aumento di volume dei mitocondri nelle cellule provate, i mioblasti coltivati in vitro.     

Intracellular localization and heterogeneity of alkaline phosphatase of Yoshida ascites sarcoma

Zusammenfassung In Yoshida-Sarkomzellen ist die alkalische Phosphatase vorwiegend in der partikelfreien Fraktion in gelöster Form lokalisiert. Gelfiltration fÜhrt zu einer Auftrennung des Enzyms im partikelfreien Überstand von 6 Fraktionen, des Enzyms in den Zellkernen bei 2 Fraktionen.

---

---

We are grateful to Tenovus (Wales) for financial support.