Aktivität der Aldolase und der Succinatdehydrogenase (SDH) in der weissen und roten Skelettmuskulatur junger und alter Ratten

Summary The activity of aldolase and succinatdehydrogenase (SDH) in white and red skeletal muscle of young (3–7 months) and old (20–30 months) rats has been determined. In addition also the SDH of liver was measured. The activity of aldolase is higher in white than in red muscles, while SDH shows a higher activity in red than in white muscles. The activity of aldolase is not influenced by ageing in white muscles, but decreased in red muscles by 23%. In old animals the activity of SDH is 34% less in white and 52% less in red muscles. In liver the activity is 44% less. The significance of these changes for the energy metabolism of skeletal muscle is discussed.     

Precocious retina development caused by receptor cell independent light effect

Summary In the retina of the mouth-brooding teleostTilapia leucosticta, light causes an accelerated development of ganglion cells. This effect is presumably not mediated by receptor and interneuronal cells.     

Zum Mechanismus derβ-Lysin-Mutase-Reaktion

Summary Using tritium labelled substrates it is shown that in the rearrangement of (S) --lysine to 3,5-diaminohexanoic acid catalysed by-lysine mutase a stereospecific hydrogen migration from C-5 to C-6 of the substrate occurs. When the reaction is carried out in the presence of [5-³H]-coenzyme B₁₂, the heavy isotope is transferred both to C-6 of 3, 5-diaminohexanoate and to C-5 of-lysine. In the latter the labelled atom occupies the same diastereotopic position as the H atom that is transferred to C-6 of the product.