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.     

Effect of cholesterol feeding and fasting on sterol synthesis in seventeen tissues of the rat

Rates of sterol synthesis were measured in 17 tissues of the rat, and the responsiveness of these rates to cholesterol feeding and to fasting was determined. The liver and gastrointestinal tract together account for 90% of synthetic activity of the whole body. After the rats had been fed cholesterol or fasted, liver synthesis was markedly decreased, whereas synthetic rates in all other organs tested were essentially unaffected (this conclusion applies to synthesis of cholesterol and of five other digitonin-precipitable tissue sterols). Consequently, the highest rate of cholesterogenesis in the cholesterol-fed or fasted rat is found in the gastrointestinal tract.