Die wirkung der β-(3-Pyridyl)-propion-und der β-(3-Pyridyl)-acrylsäure auf die Atmung der Wurzeln vonSinapis alba L.

V práci byly studovány rozdíly v ú?innosti kyseliny β-(3-pyridyl)-propionové (VIII) a β-(3-pyridyl)-akrylové (IX) v závislosti na stupni nenasycení pobo?ného ?etězce. Obě kyseliny inhibují r?st ko?ene i hypokotyluSinapis alba L. a zp?sobují inhibici sukcinátdehydrogenázového enzymového systému. Kyselina IX inhibuje zmíněný systém p?ibli?ně na dvojnásobek inhibice kyseliny VIII. Cytochromoxydázový systém z?stává témě? neovlivněn. Na základě experimen tálních výsledk? byla zp?esněna strukturní podmínka fytotoxické aktivity modelových slou?enin typu I v tom smyslu, ?e v?echny slou?eniny této struktury inhibují kromě r?stu také aktivitu sukcinátdehydrogenázového systému.     

Peroxidases of different parts of the pumpkin plant (Cucurbita pepo L.)

We compared the occurrence of peroxidase isozymes in protein extract from roots, hypocotyls and cotyledons of 10 dayCucurbita pepo plants and of adult leaves of older plants by means of starch gel and polyacryl amide gel electrophoresis. We reached maximum discrimination by means of starch gel electrophoresis: 11 zones were ascertained on the cathode side and about 2 on the anode side at pH 3.1. Two zones occurred regularly:A and (the latter having a more complicated structure). ZoneD is characteristic for roots, but is it suppressed and seldom found with leaves. On the other hand zonesC ₁ andC ₂ are clearly discernible with leaves but are substantially less evident with roots. The character of anodic zoneZ is discussed later in this paper.     

The influence of stimulating doses of 6-benzylaminopurine on awakening apple buds and on their consumption of oxygen

Byl sledován vliv 6-benzylaminopurinu na dýchání pupen? jabloně odr?dy Boskooaké v pr?běhu 5 dn? po pod7#x00E1;ní kininu. Bylo zji?těno, ?e spot?eba kyslíku stanovovaná p?ímou metodou Warburgovou je vy??í ji? prvního dne po podání 6-benzylaminopurmu a stoupá stále výrazněji a? do pátého dne, kdy je spot?eba kyslíku u pupen? stimulovaných o 75% vy??í, ne? u pupen? kontrolních.     

Enzymes of the jejunal enterochromaffine cells in man

Summary A study of enzymatic equipment of enterochromaffine cells (e.c.) in jenual biopsies obtained with a Crosby capsule in normal humans and patients with nontropical sprue was undertaken. The following enzymes were demonstrated: alkaline phosphatase and adenosine triphosphatase (cell membrane), acid phosphatase (corpuscular), non-specific esterase (diffuse and corpuscular, predominantly eserine resistant, in corpuscular localization E 600 resistant), DPN- and TPN-diaphorases and dehydrogenases of lactic acid, malic acid, isocitric acid, glucoso-6-phosphoric acid, succinic acid, -hydroxybutyric acid and -glycerophosphoric acid. Enzyme activities were not equal in all cells suggesting some type of secretory cycle. In most patients with untreated nontropical sprue or with the disease in relapse e.c. were more numerous and hypertrophic with elevated activities of non-specific esterase and acid phosphatase. Implications of these results are briefly discussed.With 8 Figures in the Text, of which 2 in Colour     

Ein Beitrag zur Kenntnis des Selektivitätsmechanismus von Pyrazon

Ve snaze identifikovat fyziologické pochody rozhodující o selektivní toxicitě pyrazonu (1-fenyl-4-amino-5-chorpyridazon-6) jsme sledovali jeho vliv na hlavní enzymové systémy ?ídící dýchání ko?en?. Zatímco jsme u ko?en? zeSinapis alba zjistili úplnou inaktivaci dehydrogenázy kyseliny jantarové—u ko?en? cukrovky je stejný enzym stimulován.     

Dehydrogenase activity and toxinogenesis of a production strain ofCorynebacterium diphtheriae during submerged cultivation

A simple biochemical procedure was obtained for studying metabolism ofCorynebacterium diphtheriae during submerged cultivation based on the modification of the assay of dehydrogenase activity using 2,3,5-triphenyltetrazolium chloride as redox indicator. Results obtained by the estimation of the dehydrogenase activity using TTC are in a good accordance with oxygen consumption assayed manometrically. By following dehydrogenase activity in submerged cultivations of a production strain ofCorynebacterium diphtheriae PW8-Weissensee we found that a massive toxin production is connected with the decrease of the activity of cells. This fall of activity occurs yet during the exponential phase of growth. Especially a sudden fall of succindehydrogenase activity exactly indicates the beginning of a considerable toxin accumulation in the medium. The presence of inhibitory concentrations of iron ions in the medium not only increases the level of dehydrogenase activity but changes its whole kinetics. A retarded and irregular fall of the activity occurs instead of a sharp one typical for good toxin production.     

Changes in the anatomical structure of the shoot apex ofSenecio vulgaris L. during ontogenis in relation to the formation of leaves and inflorescence

An investigation was made of the anatomical structure of the shoot apex ofSenecio vulgaris L. a photoperiodically neutral plant, and compared with the formation of successive leaf primordia along the axis up to the initiation of the terminal inflorescence. In the shoot apex of a germinating plant a central zone can first be distinguished from the peripheral zone which is composed of small and intensely stained cells. Later, a rib meristem appears. At the time of the initiation of the middle (the largest) leaves, the shoot apex has a distinct small central zone and a well developed peripheral zone and rib meristem. Between these zones there is a group of cells dividing in all directions, the subcentral zone. At the time of initiation of the last leaves, the central zone extends to the flanks and gradually ceases to be distinguishable. At the same time, the subcentral zone increases in size. This is caused first by cell division and later, with the initiation of the last, most reduced leaves, by enlargement of the cells. Vacuolization in the inner part of the apex and the arrangement of the superficial cells in rows parallel to the surface of the apex, is a preparatory step to the initiation of the inflorescence.