Effects of arsenite and oxamate on the in vitro functional activity of estrogen-dominated rat uterine horns

Summary Arsenite but not oxamate produce in vitro a distinct depression of estrogen-dominated uterine motility, both in the absence of substrate as well as in the presence of exogenous glucose or lactate. The addition of oxamate to preparations suspended in a medium with lactate as the sole external substrate ameliorates the depression of uterine motility elicited by arsenite.This work has been supported by grants 6638 and 6294 from the Consejo Nacional de Investigaciones Cientificas y Técnicas de la República Argentina.Senior Investigator of the Consejo Nacional de Investigaciones Científicas y Técnicas de la República Argentina.Junior Investigator of the Consejo Nacional de Investigaciones Científicas y Técnicas de la República Argentina.     

Ontogeny of the sex steroid and prolactin receptors in the male rat adrenal gland

Summary Cytosolic estrogen and androgen receptors and membrane prolactin-binding sites in the male adrenal glands showed a definite pattern during sexual development. The level of sexual steroid receptors paralleled adrenal growth, whereas prolactin binding reached its maximum value in mature rats.Lüthy, I. A., Predoctoral Fellow from the Consejo Nacional de Investigaciones Cientificas y Técnicas and Calandra, R. S., Research Career Awardee from the Consejo Nacional de Investigaciones Científicas y Técnicas, Argentina.Acknowledgments. We would like to thank Mrs D. Bas and Mrs D. B. Destéfano for the skillful technical assistance and the secretarial work, respectively. This work was partially supported by the Consejo Nacional de Investigaciones Científicas y Técnicas de la República Argentina (CONICET), and the Comisión Nacional de Energía Atómica.     

Effect of hypophysectomy on the oxidative and glycolytic metabolism of hypothalamus

Resumen En el presente trabajo se ha estudiado el consumo de oxígeno y la producción de ácido láctico en hipotálamo anterior, medio y posterior en animales hipofisectomizados. Los resultados obtenidos indicaron que la hipofisectomía produce un significativo incremento en la actividad oxidativa del hipotálamo anterior y posterior sin modificar el hipotálamo medio.

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Supported by a grant of the Consejo Nacional de Investigaciones Científicas y Técnicas de la República Argentina.

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Research Fellow from Consejo Nacional de Investigaciones Científicas y Técnicas de la República Argentina.

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Established Investigator. Consejo Nacional de Investigaciones Cientificas y Técnicas de la República Argentina.     

Direct evidence favouring the notion that erythropoietin alters iron transport across the isolated intestinal tract of the rat

Summary A simple and reproducible method, using the isolated not everted intestine of the rat, for the study of iron transport is presented. Erythropoietin (ESF) enhanced significantly the passage of⁵⁹Fe across the intestine augmenting its movement at mucosal and serosal layers of the intestinal well.This work has been supported by grant 6638 from the Consejo Nacional de Investigaciones Científicas y Técnicas de la República Argentina.Senior Investigator of the Consejo Nacional de Investigaciones Científicas y Técnicas de la República Argentina.     

Natriuresis after water loading in rats bearing transplants of pars intermedia

Summary After water loading, rats bearing ocular grafts of the pars intermedia of the pituitary showed that the content of sodium increased in urine, whereas potassium excretion and diuresis did not vary significatively. These results suggest that in the rat the pars intermedia is involved in the regulation of the electrolyte metabolism.Professor and Chairman of Histology. Member of the Investigator Career of the Consejo Nacional de Investigaciones Científicas y Técnicas de la República Argentina.     

The effect of denervation on ATP dependent calcium uptake by microsomes of the submaxillary gland of rats

Zusammenfassung Nachweis, dass in einer Mikrosomen-Fraktion von Speicheldrüsen ein ATP-abhängiges Calciumtransportsystem existiert und dass dieses von der sympathischen Innervierung der Drüsen, nicht jedoch von der parasympathischen Innervierung abhängig ist.

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Members of the Carrera del Investigador Cientifico del Consejo Nacional de Investigaciones Científicas y Técnicas de la República Argentina.

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This work was supported in part by grants No. 3211/68 and 3155/67 from the Consejo Nacional de Investigaciones Cientificas y Técnicas de la República Argentina.     

Incorporation of phospholipids in Ehrlich ascites tumor cells

Summary Ehrlich ascites tumor cells (EATC) were incubated with unilamellar vesicles (UV) or multilamellar vesicles (MV). UV and MV were incorporated differently into EATC. The increase in³²P-phospholipid in EATC in the presence of UV was 12% in 300 min. Absorption of phospholipid from MV could account for only 3%. About 50% of the UV incorporation of³²P was by endocytosis and/or fusion.This work was supported by a grant from the Consejo Nacional de Investigaciones Científicas y Técnicas, Argentina. J. L. Corchs is an investigator from the Consejo Nacional de Investigaciones Científicas y Técnicas.     

The synovial fluid hyaluronic acid in rheumatoid arthritis

Summary The intrinsic viscosity of hyaluronic acid in synovial fluid decreases significatively in mild and severe arthritis (24% and 37% respectively). Variation in hyaluronic acid concentration parallels the above results. Chondroitin-6-sulfate can be detected in about 30% of the arthritic fluids.This work was partially supported by the Consejo Nacional de Investigaciones Científicas y Técnicas de la República Argentina.     

Seasonal variations in the fertilizing capacity ofBufo arenarum (Amphibia Anura) spermatozoa

Resumen La capacidad fecundante de los espermatozoides deBufo arenarum decae más rápidamente en verano que en invierno. Ello probablemente sea debido a la presencia, durante el invierno, de factores testiculares de protección.

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This work was supported by a grant from the Consejo Nacional de Investigaciones Cientificas y Técnicas de la República Argentina and by the Population Council grant No. 71.68 awarded to the Consejo Nacional de Investigaciones Cientificas y Técnicas to be administered by the Instituto de Biología, Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán.

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The author is most grateful to Dr.F. D. Barbieri for his kind discussion and helpful advice in the course of the present study.     

Regulatory properties of the citrate synthase fromRhodospirillum rubrum

Summary Citrate synthase, purified 600-fold fromRhodospirillum rubrum, is activated by KCl and inhibited by ATP and NADH; the effect of the latter inhibitor is completely counteracted by AMP and partially counteracted by KCl.This work was supported by grants from the Consejo Nacional de Investigaciones Cientificas y Técnicas de la República Argentina and the Consejo de Investigaciones de la Universidad Nacional de Rosario. JJC, and EM and AIH, are members of the Carrera del Investigador Cientifico of the former and the latter institutions, respectively.     

The citrate synthase fromBacillus stearothermophilus

Summary Citrate synthase has been purified to apparent homogeneity fromBacillus stearothermophilus. Its kinetic and regulatory properties, and molecular weight, are similar to those of the enzymes from suitable mesophilic counterparts, but its thermal stability is considerably greater.This work was supported by grants from the Consejo Nacional de Investigaciones Cientifficas y Técnicas de la República Argentina and the Consejo de Investigaciones de la Universidad Nacional de Rosario. AIH is a member of the Carrera del Investigador of the latter institution, and JJC is a member of the Carrera del Investigador Cientifico of the former institution.     

Effect of hydrocortisone administration on erythropoiesis in the adrenalectomized dog

Resumen La administración de 2 mg/kg/día de hidrocortisona durante 40 días en perros adrenalectomizados 4 meses antes produjo elevación del volumen de la masa roja circulante y de la síntesis de hemoglobina. El tratamiento con la hormona en la dosis de 4 mg/kg/día durante los siguientes 40 días produjo más aumento de la actividad eritropoyética de la médula ósea, una gran proporción de la cuál fue inefectiva en términos de producción de eritrocitos, produciéndose un descenso de la masa roja circulante.

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Member of the Carrera del Investigador Científico del Consejo Nacional de Investigaciones Científicas y Técnicas de la República Argentina.

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This work was supported by Grant No. 1126d from the Consejo Nacional de Investigaciones Cientificas y Técnicas de la República Argentina.     

The extracellular protease fromPseudomonas fluorescens

Summary An extracellular protease has been purified from cultures ofPseudomonas fluorescens. It is a metalloenzyme with a molecular weight of 37,000±3,700, able to digest casein, hemoglobin and gelatine.This work was supported by grants from the Consejo Nacional de Investig ciones Científicas y Técnicas de la República Argentina, and the Consejo de Investigaciones de la Universidad Nacional de Rosario. JJC is a member of the Carrera del Investigador Científico, and SMJ the recipient, of a schollarship, of the former institution.     

The acidic glycosaminoglycans in gastric mucosa of athyroid rats: The effects of L-tri-iodothyronine

Summary Hyaluronic acid is increased about 12%, whereas dermatan sulfate is decreased about 34%, in gastric mucosa of athyroid rats when compared with controls. Administration of 2 doses of L-tri-iodothyronine reversed the effects of thyroidectomy.This work was partially supported by the Consejo Nacional de Investigaciones Científicas y Técnicas de la República Argentina.     

On the regulatory properties of a halophilic malic enzyme fromHalobacterium cutirubrum

Summary The NADP-linked malic enzyme fromHalobacterium cutirubrum is strongly inhibited by acetyl-CoA and NADH, and rather weakly inhibited by oxaloacetate and glyoxylate, in the presence of very high KCl concentrations (3,M), considered physiological for the extremely halophilic bacteria.This work was supported by grants from the consejo Nacional de Investigaciones Científicas y Técnicas de la República Argentina, and the Consejo de Investigaciones de la Universidad Nacional de Rosario. JJC and MCV are members of the Carrera del Investigador Científico of the former and the latter institutions, respectively.     

Disappearance of different substances in contact with the external surface of the brain

Résumé La disparition de différentes substances en contact avec la surface externe du cerveau est étudiée. Les temps moyens de disparition de celles-ci suggèrent l'existence d'une barrière s'opposant au passage de ces substances du compartiment subarachnoïde crânien au tissu nerveux.

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Work supported by grants from the Consejo Nacional de Investigaciones Cientificas y Técnicas (Argentine).     

Bilateral ovarian hypertrophy in pituitary-grafted rats

Summary Large masses that looked like tumours were found in place of the ovaries in rats with isotransplants of pituitaries, 11 months after this procedure. They were interpreted as being due to massive bilateral cystic hyperplasia and hypertrophy of both ovaries.Acknowledgments. This work was supported by research grants from the Fundación Cherny and from The Consejo Nacional de Investigaciones Científícas y Técnicas.     

Hydrogen peroxide generation inTrypanosoma cruzi

Summary Homogenates from T. cruzi epimastigotes produced 3.4 pmoles H₂O₂/min 10⁶ cells, as detected by the cytochrome c peroxidase assay. Addition of NADH or NADPH increased H₂O₂ production by a factor of 3 and 5, respectively. When supplemented with NADH and NADPH, the mitochondrial, microsomal, and supernatant fractions produced H₂O₂, the soluble fraction and the mitochondrial membranes being apparently the main generators of H₂O₂. The epimastigote homogenates showed cyanide-sensitive superoxide dismutase activity, equivalent to 0.28 g bovine superoxide dismutase per mg homogenate protein.This investigation was supported by grants from Consejo Nacional de Investigaciones Cientificas y Técnicas (CONICET) Argentina and the Scientific Office, American States Organization.Career Investigator of CONICET.     

Effect of estrogens on LH- and FSH-levels in prepuberal male and female androgenized rats

Summary This paper has demonstrated that neonatal androgenization increases in prepuberal male and female rats the FSH-levels without changes in LH, indicating that the sexual differences in the control of FSH is a relevant process that takes place during the differentiation of the hypothalamus.Supported by a grant from the Consejo Nacional de Investigaciones Cientificas y Técnicas, Rep. Argentina.Acknowledgment. We are grateful to NIAMD, Rat Pituitary Program, for the reagents for the radioimmunoassays.     

In vitro formation of a MSH-releasing agent by hypothalamic extracts

Résumé La fraction mitochondriale d'extraits du noyau paraventriculaire du rat incubée avec de l'oxytocine produit la formation d'un agent capable de libérer MSH de l'hypophyse. Les résultats suggèrent que la formation de l'agent qui libère la MSH hypophysaire résulte de la dégradation enzymatique des hormones neurohypophysaires.

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This work was supported by the Consejo Nacional de Investigaciones Cientificas y Técnicas of Argentina.