Effect of clofibrate on the phospholipid biosynthesis in rat liver

Summary The effect of clofibrate on rat liver phospholipid biosynthesis was studied using³²P as a precursor. Phospholipid classes, levels and specific radioactivity were evaluated. Significant increases in levels of phosphatidylethanolamine and phosphatidylcholine were found and could account for the observed increase in total phospholipids. Specific activity of phosphatidylserine increased and that of phosphatidylethanolamine decreased. This fact suggests that clofibrate seems to alter the systems engaged in the transformation occurring within the different classes of phospholipids but not the de novo biosynthesis.     

Effect of clofibrate on the enzyme activity of rat liver plasma membranes

Summary The activity of 3 plasma membranes marker enzymes (5-nucleotidase, Mg⁺⁺-ATPase and alkaline phosphodiesterase-I) was determined in plasma membranes isolated from liver of control and of clofibrate-treated rats. A complete identity of plasma membranes enzyme activity in the 2 groups of experimental animals was observed for the 3 enzymes studied.     

Effect of prostaglandin E1 on cholesterol biosynthesis in rat liver

Riassunto La prostaglandina E₁ (PGE₁) ha un duplice effetto sulla sintesi epatica del colesterolo: a basse concentrazioni determina un incremento della incorporazione di acetato in colesterolo, mentre a concentrazini superiori a 50 nmoli essa determina una riduzione di questo paramentro.     

Effect of silica on protein biosynthesis by rat liver cell-free systems

Riassunto È stata studiata l'azione di particelle di silice a struttura cristallina e non cristallina sulla incorporazione di leucina-1-C¹⁴ nelle proteine microsomiali di fegato.La silice inibisce l'incorporazione, ma con diversa intensità. Ciò appare essere in rapporto con la struttura delle particelle impiegate.     

Inducing effect of clofibrate on alkaline phosphatase and histidine-glyoxylate aminotransferase in rat liver

Summary The activity of plasma membrane alkaline phosphatase and both mitochondrial and peroxisomal histidineglyoxylate aminotransferase was significantly increased in the livers of male rats following treatment with the hypolipidemic drug clofibrate. Cycloheximide or puromycin administration to rats inhibited the effects of clofibrate.     

Ethionine and methionine biosynthesis in rat liver

Zusammenfassung Injektionen von Ethionin oder Homocystein steigern die Transmethylierung in der Leber.     

Reactivity of some transition metals on nuclear protein biosynthesis in rat liver

Zusammenfassung An enzymatisch aktiven Leberzellkernen aus Ratten wurde die Reaktivität von Hg²⁺, Mn²⁺, Fe³⁺ und Cr³⁺ auf die nukleare Proteinbiosynthese geprüft. Hg²⁺-Ionen hemmen den¹⁴C-Aminosäure-Einbau vollständig, während Mn²⁺ und Fe³⁺ eine schwache Stimulierung verursachen. Die¹⁴C-Einbaurate ist nach Cr³⁺-Zusätzen stark erhöht. Es konnte gezeigt werden, dass die Cr³⁺-Stimulierung nicht durch Adsorption zu erklären ist.     

Effect of PGE1 on lipogenesis in perfused rat liver.

In perfused livers of 24 hour-fasted rats, PGE1 (prostaglandin E1) infused continuously into the perfusate, was found to cause a 45% increase in the incorporation of 1-14C acetate into liver fatty acids. PGE1 was found to have no effect, however, on the activity of the key lipogenic enzymes.     

Effect of acetone on VLDL secretion by the isolated rat liver.

High acetone levels occur in uncontrolled diabetes and after isopropanol administration to rats. In both conditions, very low density lipoproteins (VLDL) secretion is depressed. Acetone, hoever, failed to affect the VLDL secretion rate by the isolated perfused rat liver, suggesting that this metabolite is not involved in impaired VLDL production in diabetes and after isopropanol administration.     

Effect of insulin on lateral diffusion of pyrene in rat liver plasma membrane.

The yield of excimer formation by pyrene molecules inserted in rat liver plasma membranes in sensibly decreased in the presence of 1 nM insulin. This effect can be interpreted as indicating a decrease of the value of the translational diffusion coefficient of the dye within the membrane.     

Effect of hepatectomy on the growth of the foetal rat liver

Résumé Les auteurs ont utilisé deux lots des Rates portantes. L'un d'eux a été soumis à la laparotomie et l'autre à une hépatectomie partielle le 16ème jour de la gestation. Les animaux ont été sacrifiés à des dates échelonnées après l'intervention. Le poids des embryons et celui de leur foie, ainsi que la teneur en DNA du foie ont été mésurés.L'hépatectomie de la mère ralentit la croissance des embryons sans aucun effet spécifique sur le foie embryonnaire.     

Effect of some hyper- and hypo-cholesteremic drugs on the cholesterol biosynthesis by liver homogenates

Riassunto Nè il Triton W R 1339 nè l'acido feniletilacetico sono capaci di modificare significativamente la biosintesi di colesterolo da parte di omogenati di fegato di ratto incubati a 37°C.     

Effect of PGE1 on lipogenesis in perfused rat liver

Summary In perfused livers of 24 hour-fasted rats, PGE₁ (prostaglandin E₁) infused continuously into the perfusate, was found to cause a 45% increase in the incorporation of 1-¹⁴C acetate into liver fatty acids. PGE₁ was found to have no effect, however, on the activity of the key lipogenic enzymes.