Chromosomes and giemsa-bands of the Idaho spotted ground squirrel,Spermophilus brunneus (Howell)

-Spermophilus brunneus . , 13 18 ,S. brunneus S. townsendii mollis (2n=38) , , ; ;S. brunneus . S. brunneus , Spermophilus.

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Supported by National Science Foundation Grants No. GB32114X and No. GB 29131X, and the Sprague Foundation. We thankD. Pozin for technical assistance.     

Reactive synthesis of DNA and mitotic division in atrial heart muscle cells following ventricle infarction

/- 5 - / . , .     

Artificial lung ventilation during diaphragmatic paralysis

ÿe , CO₂ . CO₂ ÿe . , ÿe , .     

Proteins of venezuelan equine encephalomyelitis virions

. : (. . 59,000–61,000 ), (34,000–38,000) (15,000–18,000).     

DNA synthesis and mitoses in atrial myocytes of rats with aortal stenosis

, . 2- , 1,60 ±0,59% , 0,96 ± 0,44% — . ë . , ³- .     

X-ray research of polycrystals. X-ray diffraction methods for precision determinations of polycrystal lattice parameters over unsolved double lines

. - .     

Extrapyramidal pathways with monosynaptic effects upon primate α-motoneurons

, , , , , -.     

The peculiarities of capacitance vessel reflex responses

Conclusion Changes of the vessel capacity resulted from the pressor synocarotid reflexes, intestinal chemoreflexes and reflexes from the right atrium or ventricle and electric stimulation of the somatic nerve afferents can be either similarly or differently directed as compared with the responses of the resistance vessels.

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, , , .

     

Monoamine oxidase activity in membrane structures of rat liver cell

, .     

Changes in the lumen of coronary vessels under oligemic hypotension

Conclusions The decrease of circulating blood volume, resulting in oligemic hypotension, may evoke in anaesthetized cat the active constrictory coronary vessel responses of 2 types, one occuring immediately after start of the hypotension and the other having a significantly prolonged latency.

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, , , , ( 4 ), ( 45 ).

     

Mass spectrometric determination of the amino acid sequence in arginine-containing peptides

aa, a-a a- a aa - aa a -a .     

Antihypertensive effect of Co-factors of the synthesis and precursors of nucleic acids in experimental hypertension

, ₁₂, .     

Microbiological transformation of biflavone

Summary Incubation of 5,5-7,7-tetramethoxy-8,8-biflavone withAspergillus niger results in the formation of 4,4-dihydroxy-5,5-7,7-tetramethoxy-8,8-biflavan.Part of this work was done at Allahabad University, Chemical Laboratories.     

A study of the mechanism of lowering the sensitivity of smooth muscle to noradrenalin with sympathetic hyperinnervation

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The benzilic acid rearrangement of 3α,17β-Diacetoxy-11-hydroxy-12-oxo-5β-androst-9(11)-ene

Zusammenfassung Die Bildung von 11-Carboxy-3, 11, 17-trihydroxy-13-C-nor-5-androstan 11a,17-Lakton aus 3, 17-Diacetoxy-11-hydroxy-12-oxo-5-⁹(11)-androsten wird beschrieben. Der Mechanismus und die Stereochemie dieser Umwandlung (Retro-Aldolkondensation und Benzilsäureumlagerung) wird diskutiert.     

Starfish saponins VII. Structure of luzonicoside,a further steroidal cyclic glycoside from the pacific starfishEchinaster luzonicus

Summary On the basis of comparative chemical and spectral data, the structure of the major saponin, luzonicoside, from the starfishEchinaster luzonicus has been elucidated as2. This is a further example of a novel class of steroidal cyclic glycoside from starfish of the genusEchinaster. Its structure includes a ⁷, 3,6-dioxygenated-23-oxosteroidal moiety, already found in the saponins ofEchinaster sepositus, and a trisaccharide moiety, -D-galactopyranosyl-(12) -L-arabinopyranosyl-(12)--D-glucuronopyranosyl, bridging C-3 and C-6 of the steroid.This contribution is part of the Progetto Finalizzato Oceanografia e Fondi Marini del C.N.R., Roma.Acknowledgments. We wish to thank Mrs M. Pusset, Laboratoire des Plantes Médicinales du C.N.R.S., Nouméa, for the extraction of starfish and the divers of the Centre Q.R.S.T.O.M. de Nouméa for collection.     

Effect of dipyridamole on glomerular mesangial cell ecto-5′-nucleotidase expression

Although dipyridamole has been extensively studied as an anti-aggregating agent, its mechanism of action has not been elucidated. Cultured mesangial cells were treated with dipyridamole 1–100 M from 6–72 h. Ecto-5-nucleotidase activity approximately doubled (from 115±11 to 226±14 nmol/min/mg) after treatment with 100 M dipyridamole for 72 h. This effect was concentration- and time-dependent. Cycloheximide, an inhibitor of protein synthesis, did not alter basal 5-nucleotidase activity. However, it prevented stimulation by 5 M dipyridamole. Adenosine availability at the receptor sites was increased by dipyridamole and S-(p-nitrobenzyl)-6-thioinosine (NBTI), which inhibit adenosine uptake into the cell. Addition of dipyridamole or NBTI to the adenosine-treated mesagial cells produced an additive increase in ecto-5-nucleotidase activity. Dipyridamole, through its effect on extracellular adenosine and ecto-5-nucleotidase, may have an influence upon regulation of the glomerular microcirculation.     

Hydra vulgaris ω10-lipoxygenase is used in vivo to synthesize new α-linolenic acid metabolites

Previous studies conducted in cytosolic extracts of the freshwater hydrozoanHydra vulgaris led to the finding of an abundant 11(R)-lipoxygenase catalyzing the peroxidation of polyunsaturated fatty acid (PUFAs) on the tenth carbon atom from the aliphatic end (10 peroxidation). Here we describe experiments aimed at identifying the actual metabolites generated in vivo by such enzymic activity. Homogenates ofH. vulgaris polyps were analyzed by HPLC. This showed the presence of three major components chromatographically identical to three metabolites obtained when incubating the homogenates with exogenous -linolenic acid (-LA). The presence, in extracts of polyps prelabelled with [¹⁴C]--linolenic acid, of radioactive metabolites displaying the same chromatographic properties, substantiated the hypothesis that the natural products isolated in vivo are derived from -LA. Gas chromatographic analyses revealed that this was the most abundant PUFA in both free and phosphoglyceride-bound fatty acid pools. [¹H]-NMR analysis of the endogenous substances, carried out in comparison with products obtained from exogenously incubated -LA, indicated that their structures were those of 9-hydroxy-, 9-hydroperoxy- and 9-keto-octadeca-10E-12Z-15Z-trienoic acids (9--HOTrE,-HPOTrE and-KOTrE).Hydra homogenates transformed 9--HPOTrE partly into 9--HOTrE and partly into 9--KOTrE. Chiral phase HPLC conducted on 9--HOTrE established that this metabolite was composed mostly of theR anantiomer. These observations, and the finding that the presence of exogenous arachidonic acid in incubated homogenates significantly reduces the production of -LA metabolites, provide strong evidence that these compounds are produced by an enzymic activity identical to the previously-describedH. vulgaris (R)-10-lipoxygenase. Further experiments suggested that -LA, acting as the native substrate for this enzyme, is mainly esterified on the 2 position ofHydra phosphoglycerides, and that the production of the -LA metabolites described here for the first time from natural sources, can be potentially enhanced in vivo by stimuli activating phospholipase A₂.     

A study of excitation-contraction coupling in frog tonic muscle fibers ofRana temporaria

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