The effect of monoamine synthesis-inhibitors on the ovarian compensatory hypertrophy

Resumen La administración continuada de-metilpara-tirosina, un inhibidor de la síntesis de catecolaminas, impide la hipertrofia compensadora del ovario en ratas. Este efecto es prevenido por la simultânea injección de DOPA, un. precursor de las catecolaminas. El grado de la hipertrofia compensadora del ovario no fue modificado por lap-cloro-fenilalanina, un inhibidor de la síntesis de serotonina. El estudio histológico de los ovarios de los animales tratados con MPT sugiere que ésta bloquea la ovulación, no modificando aparentemente la secreción tonica de las gonadotrofinas FSH y LH.

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A grant from the Consejo Nacional de Investigaciones Científicas y Tecnicas of Argentina supported this research.-methylp-Tyrosine was a gift from Dr.Karl Pfister of Merck Sharp & Dohme Research Laboratories.     

Dissociation of glucocorticoid effects of C-21 steroids at high concentrations in thymocytes

Summary A dissociation between inhibition of RNA synthesis and cell lysis was observed when thymocytes of adrenalectomized rats were incubated with high concentrations of pregn-4-ene-11-ol-3, 20-dione and pregna-1,4-diene-11-ol-3,20-dione. In contrast, no dissociation of these effects was found with the typical glucocorticoids cortisol and corticosterone, nor with their 1,4-diene analogs under the same conditions.Acknowledgments. This work was supported by grants from the Consejo Nacional de Investigaciones Científicas y Técnicas de la República Argentina to the Instituto de Biologia y Medicina Experimental and the Programa de Regulación Hormonal y Metabólica as well as by financial help from the Secretaría de Ciencia y Tecnología.     

Delay in skin allograft rejection in rats grafted with fetal adrenal glands

Resumen Se ha observado en este trabajo que el injerto de suprarrenales de fetos en ratas de 6 días de edad determina aumento del tiempo de supervivencia de aloinjertos de piel realizados al 10° día de vida en relación a los testigos y a ratas injertadas con suprarrenales de adulto. Un efecto similar se observó cuando se administró diariamente a partir del 6° día de vida 16-metil prednisona en dosis altas que producían gran trastorno del crecimiento, evidente disminución de peso del timo y en algunos casos muerte del animal.

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Fellow of the Consejo Nacional de Investigaciones Centificas y Técnicas (Argentina).     

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.     

Differential effect of hypophysectomy on skin and tracheal cartilage glycosaminoglycans

Resumen En 12 ratas normales y en 12 hipofisectomizadas 150 días antes se determinaron las concentraciones de ácidos urónicos, glicoproteínas, ácido hialurónico, heparitín sulfato, condroitín-4-sulfato, condroitín-6-sulfato, dermatán sulfato y heparina en piel y cartílago traqueal. Estos estudios demostraron dos hechos: (1) un efecto distinto de la hipofisectomía sobre piel y tráquea en relación con el metabolismo de las glicoproteínas y el ácido hialurónico, cuyas concentraciones aumentaron en la primera y descendieron en la segunda; (2) una disociación entre el comportamiento del ácido hialurónico y los glicosaminoglicanos sulfatados en piel, aumentando la concentración del primero y disminuyendo las correspondientes a los segundos en forma variable segÚn la fracción considerada.

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

The acidic glycosaminoglycans of the synovial fluid in rheumatoid arthritis

Resumen Se estudiaron los glucosaminoglucanos del líquido sinovial de la rodilla de pacientes con artritis reumatoidea clásica. El nivel de glucosaminoglucanos totales desciende en la artritis un 55% comparado con los controles. Esto es debido principalmente a la disminución del ácido hialurónico (59%). Se confirmó la presencia de pequeñas cantidades de controidin-4-sulfato y se detectaron trazas de una sustancia similar al condroitin-6-sulfato.

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

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This work was partially supported by research grants from the CONICET, Republica Argentina.     

Changes in serum proteins due to lesion or resection of the olfactory bulbs of the rat

Resumen La sección y extirpación bilateral de los bulbos olfactorios, en ratas de ambos sexos, producen disminución de las proteínas séricas totales, albumina y globulinas y, sin modificaciones de la globulina. Esa disminución se hace significativa 21 días después de las operaciones.     

Hemodynamic changes in rats without adrenal medula submitted to hypovolemic shock

Resumen La extirpacion de la medula suprarrenal no provoca alteraciones de la hemodinamia en ratas estudiadas en condiciones basales, mientras que durante el shock hipovolemico las ratas meduloprivas presentan un volumen minuto cardiaco menor, y un aumento de la presion arterial media y de la resistencia periferica total, en relacion a los testigos normales sometidos al mismo tipo de shock.

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This work has been partially supported with a grant from the Consejo Nacional de Investigaciones Cientificas y Técnicas. The isotopes were obtained through the Comisión Nacional de Energía Atomica.

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Established Investigator. Carrera del Investigador Científico del Consejo Nacional de Investigaciones Científicas y Técnicas de la República Argentina.     

Narciclasine,an inhibitor of protein synthesis. Action onAllium cepa L. root meristems

Summary Shortening of nucleologenesis time in a synchronous cell population, labelled as binucleate, by a caffeine pulse and fall in frequency of prophases are related to narciclasine inhibition of protein synthesis inAllium cepa L. meristems.Acknowledgments. We gratefully acknowledge Dr D. Vázquez and Dr A. Jiménez, from the Instituto de Bioquímica de Macromoléculas, for calling our attention to this protein synthesis inhibitor and providing us samples both of narciclasine andNarcissus bulbs. We also greatly appreciate Dr B. Rodriguez and Dr F. M. Panizo of the Instituto de Química Orgánica (Departamento de Productos Naturales) for their valuable help in isolation and characterization of narciclasine, and for laboratory facilities. The work has been partially supported by the Comisión Asesora para la Investigación Científica (Spain). A.S. has a fellowship awarded by the Instituto de Cultura Hispánica, Spain.     

Effect of theophylline and triiodothyronine on some early estrogenic responses in the rat uterus

Summary Theophylline increases and triodothyronine decreases uterine edema induced by physiological doses of estradiol-17. Both of them decrease estrogen-induced uterine eosinophilia and the number of blood eosinophils, suggesting an explanation for the results in the uterus.Acknowledgments.—We wish to thank Dr G. Pineda, Salvador Hospital, Santiago, for the gift of L-triiodothyronine (Sigma). This work was supported by grant B 012-783, Servicio de Desarrollo Científico y Creación Artística, University of Chile.     

Scarites buparius,a caraboid beetle with an X1X2Y sex-chromosomes system

Summary Scarites buparius has 2n=37 and n=17+X₁X₂Y. This multiple sex-chromosomes system seems to be the result of a reciprocal translocation between the primitive X-chromosome and an autosome. This is the first caraboid beetle, exceptingCicindela spp., that has multiple sex-chromosomes.This work has been supported by a grant of the Comisión Asesora de Investigación Científica y Técnica, No. 1.552.     

Metabolism of amphibian spermatozoa in relation to their motility

Summary Bufo arenarum spermatozoa were able to sustain motility both under aerobic and anaerobic conditions. In aerobiosis, the oxygen consumption varies between 2.6 and 4.2 l O₂/10⁸ cells/h at 30°C. The synthesis of lactic acid by anaerobic spermatozoa demonstrated the existence of an active glycolytic pathway.This work was supported by the Consejo Nacional de Investigaciones Científicas y Técnicas and the Latinoamerican Program of Human Reproduction (PLAMIRH), grant 34-95-2-75.     

Inhibition of the NADP-linked glutamate dehydrogenase fromTrypanosoma cruzi by silver nitrate

Summary The purified NADP-linked glutamate dehydrogenase fromTrypanosoma cruzi was strongly inhibited by silver nitrate. The inhibition was reversed by reduced glutathione, and was modified by the presence of the substrates during preincubation of the enzyme with the inhibitor.This work was supported by grants from the Consejo Nacional de Investigaciones Científicas y Técnicas de la República Argentina and the Secretaría de Estado de Ciencia y Technología de la República Argentina. JJC is a member of the Carrera del Investigador Científico, and SMJ a Research Fellow, of the former Institution.     

Ultrastructural and histochemical studies on the mucous granules in the tube feet of the starfishEchinaster brasiliensis

Resumen Es estudiada la ultraestructure y la histochimica de gránulos de secreción de células glandulares mucosas del pié ambulacrario de la estrella de marEchinaster brasiliensis. Estos gránulos secretores tienen una organización distincta comparada con aqueles encuentrados en la estrella del marAsternia stellifera anteriormente estudiada. Así son organizados en forma de circolos concentricos en torno du un eixo.

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Acknowledgments. The authors wish to express their thanks to Mrs.Arlene Mayhugh for her valuable technical assistance. This work was, in part, supported by grants from the Fundação de Amparo à Pesquisa do Estado de São Paulo, Brazil.

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Pesquisadora-Conferencista do CNPq (TC 308-Proc. 9051/70).     

The effect of RNA synthesis inhibitors on prenucleolar bodies

Summary Inhibition of RNA synthesis prevents the fusion of prenucleolar bodies in the NOR region during nucleologenesis. However, their physical coalescence between themselves is increased, as shown inAllium cepa L. meristems.This work has been partially supported by the Comisión Asesora para la Investigación Científica y Técnica (Spain). We greatly acknowledge M.L. Martínez and O. Partearroyo for their skilfull technical and secretarial work.     

Occurrence of adrenaline and noradrenaline cells in the adrenal gland of the gentoo penguin (Pygoscelis papua)

Resumen Se investigó con microscopía óptica y electrónica y aplicando la técnica de glutaraldehido-plata la distribución y características de las células que contienen adrenalina y noradrenalina en el pinguino Papúa (Pygosceles papua).

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I thank Dr. J. H.Tramezzani and Dr. G. F.Wassermann for their important advice. I thank also Mrs.Isabel López de Farías for her technical assistance. This work was supported in part by the Argentine Antarctic Institute.     

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.     

Pineal-related changes in cyclic AMP levels of rat medial basal hypothalamus

Summary Pinealectomy (Px) in adult male rats resulted in increased cyclic AMP accumulation by medial basal hypothalamic (MBH) explants 3 and 7 days after surgery. 24 h after superior cervical ganglionectomy (Gx) an augmented MBH cyclic AMP accumulation was observed. The effects of Px and Gx were additive, as revealed in animals subjected to Gx 3 days after Px.This study was supported by grants from the Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) (N^o 6638) and from the Fundación Alberto J. Roemmers, Argentina.     

Cytogenetics of South American akodont rodents (Cricetidae). V. Segregation of chromosome No. 1 polymorphism inAkodon molinae

Summary Akodon molinae is polymorphic with 2n=42, 43, 44, where the metacentric autosome No. 1 is homologous to 2 acrocentrics 1a and 1b. Matings between 2n=43 heterozygotes 1/1a, 1b gave a surplus of 1/1 offspring, a moderate reduction of heterozygous and a strong reduction of homozygous 1a, 1b/1a, 1b offspring. The latter type also has a highly reduced fertility.This work was supported by grants from the Consejo Nacional de Investigaciones Científicas y Técnicas, the Comisión de Investigaciones Científicas de la Provincia de Buenos Aires and the Organización de Estados Americanos.     

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.