Defensive steroids from a carrion beetle (Silpha americana)

Summary The defensive anal effluent discharged bySilpha americana in response to disturbance contains a mixture of steroids stemming from a glandular annex of the rectum. The compounds have been characterized as 15-hydroxyprogesterone (1, principal component), 5-pregnan-15-ol-3, 20-dione (2), 5-pregnan-3, 15-diol-20-one (3), 5-pregnan-7, 15-diol-3,20-dione (4), 5-pregnan-3, 7, 15-triol-20-one (5), 5-pregnan-16-ol-3,20-dione (6), and 5-pregnan-3, 16-diol-20-one (7), none previously found in insects. Bioassays with jumping spiders showed compounds1 and6 to be feeding deterrents at the 1 g level.Paper No. 78 of the series: Defense Mechanisms of Arthropods. Study supported by NIH (Grants AI-02908, AI-12020). We thank Maura Malarcher and Maria Eisner for excellent technical help, and the Squibb Institute of Medical Research for samples of authentic reference compounds.     

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

, ₁₂, .     

Inhibition of sodium transport in frog skin by cardiac glycosides of different molecular structure

p 19-OM no- . ; — .     

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

aa, a-a a- a aa - aa a -a .     

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.

---

---

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

Rhythmic activity in frog (Rana pipiens) visual system

Zusammenfassung Nachweis, dass die Netzhaut-Ganglienzellen dritter Klasse beiRana pipiens auf Beleuchtungsperiodenausgleich reaktiv rhythmische potentialfolgen von bursts und firing erzeugen. Als wirksamste Beleuchtungsperioden erwiesen sich solche im mesopischen Bereich bei Mindestdauer von 15 sec. Weder skotopische noch photopische Belichtungen führten zu rhythmischer Aktivität.     

Giant pigment granules in dermal melanocytes of rat scrotal skin

Summary Giant melanosomes, ellipsoidal (1.5 m×1.3 m) or spherica (1.1 m–1.4 m in diameter) exist in the scrotal skin of the black pelted Long Evans rat. They are longer and wider than normal stage IV melanosomes (0.7 ×0.4 m) found in theses dermal melanocytes.The authors acknowledge with gratitude, the technical assistance of Evelyn Ann Flynn. This work was supported by grant AM 20669-16 from the National Institute of Arthritis, Metabolism, and Digestive Diseases, USPHS.     

Über die Zytologie der Parthenogenese und der Geschlechtsbestimmung bei der GallmückeOligarces paradoxus Mein

Summary InOligarces paradoxus, the chromosomal behaviour was compared during pedogenetic development of and . The -egg undergoes a single non-reductional maturation division, the -egg shows two divisions which result in reduced nuclei. After maturation in the -egg, the number of chromosomes is restored by endomitosis. The nuclei of germ-line cells contain a high number of chromosomes (: 74\2-82; : at least 58) in both sexes. In somatic nuclei, the number is diminished by elimination to 10 in , to 5 in .     

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

. - .     

Artificial lung ventilation during diaphragmatic paralysis

ÿe , CO₂ . CO₂ ÿe . , ÿe , .     

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.

---

, , , .

     

Effect of some monoamine oxidase inhibitors on deamination of biogenic monoamines by rat liver mitochondrial monoamine oxidase

N--N- MAO , , .     

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

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

Proteins of venezuelan equine encephalomyelitis virions

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

Extrapyramidal pathways with monosynaptic effects upon primate α-motoneurons

, , , , , -.     

Orally administered melatonin stimulates the 3α/β-hydroxysteroid oxidoreductase but not the 5α-reductase in the ventral prostate and seminal vesicles of pinealectomized rats

Summary Pinealectomized rats were treated orally with melatonin (MEL) for 14 days. Prostates and seminal vesicles were investigated for the activity of the 4-3-ketosteroid-5-oxidoreductase (5-R) and of the 3/-hydroxysteroid-oxidoreductase (3-HSO). The activity of the 3a-HSO was significantly stimulated (p<0.01, Friedman test) when compared to controls. The activity of the 5-R did not change significantly.This work was supported by the Deutsche Forschungsgemeinschaft, Sonderforschungsbereich 34 (Endokrinologie).     

The effect of chloramphenicol analogs on protein biosynthesis in a cell-freeEscherichia coli B system

a aaa a aa aa a a E. coli aa, a aa aa a , a a aa - a .

---

---

Laboratory of Biological Investigations.

---

Laboratory for Chemistry of Antibiotics.     

A study of the mechanism of polymyxin M inactivation

.I.NH₄OH , N N - - ,-. , .     

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.

---

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