Evidence against the involvement of cyclic GMP in the insulin-stimulation of lipoprotein lipase activity in fat cells

Under in vitro experimental conditions in which insulin increases adipose tissue lipoprotein lipase, cyclic GMP or dibutyryl cyclic GMP has no effect on this enzyme in rat adipose tissue fragments, or on either the intra- or extracellular forms of this enzyme in isolated fat cells. These results do not support the involvement of cyclic GMP in the insulin-stimulation of lipoprotein lipase in adipose tissue.     

Evidence against cyclic GMP acting as a direct modulator of active sodium absorption in rat cecum

Summary Cyclic GMP concentrations were measured in rat cecum mucosa in vivo when the net absorption of sodium, chloride and fluid was stimulated by methylprednisolone (MP). Whereas Na–K-ATPase specific activity was increased by MP, suggesting enhanced active sodium transport, cyclic GMP levels remained unaffected.Acknowledgments. We thank Miss U. Kautz for engaged technical assistance and Dr G. Schultz for valuable discussions.Supported by Deutsche Forschungsgemeinschaft grant Lo 114/10.     

The effect of lipase activity on the fat content ofStaphylococcus aureus

Résumé Deux souches deStaphylococcus aureus, l'un positif pour Tween 80 et l'autre négatif pour Tween 80 ont la propriété de décomposer des substrates lipidiques. Tous deux peuvent libérer des esthers d'acides gras contenant 16 atomes de carbone (longs et courts). Après l'action duStaphylococcus aureus positif pour Tween 80, des esthers contenant des longs acides gras sont aussi libérés. Dans ces conditions, la quantité totale de lipide bactérien devient plus élevée. Ces deux staphyloques incorporent de la même manière les acides gras libérés.     

Effect of thymectomy on lipoprotein lipase activity in the serum and the heart of rats

Zusammenfassung Entfernung der Thymusdrüse führt zu einer Abnahme des Gehaltes an Lipoprotein-Lipase in Serum und Herzmuskel der Ratte. Die Veränderung wird im Verlaufe der ersten 3 postoperativen Wochen als signifikant betrachtet.     

Comparison of circulating lipoprotein lipase activity in Zuckerfa/fa andFa/-rats

Summary Lipoprotein lipase activity was determined in Zucker rats by assaying VLDL radioactivity. Animals were i.v. injected with³H₂-oleic acid and¹⁴C-glycerol with or without Triton WR 1339. This enzymatic activity was higher infa/fa rats than in non-obeseFa/-rats.     

The effects of a heterologous antibody against a crude lipoprotein lipase fraction in mice]

The antigens contained in a crude lipoprotein-lipase fraction from the Rabbit adipose tissue have no effect on Mice, even after daily injections for several months. But they induce an immune reaction in Sheep, allowing one to produce several immune sera with a high physiological activity, without any specific barrier between Rabbit and Mouse. After total absorption of these immune sera by normal Rabbit serum, the remaining antibodies have an activity against esterasic lipoproteins. Small doses of these antibodies induce in Mice marked hyperplastic and degenerative reactions of the adipose tissue and an extensive lysis of the pancreas. A correlative high lymphocytic activation, producing B and T immunoblasts, is induced.     

Circadian variation of adrenocortical cyclic nucleotides (cyclic AMP and cyclic GMP) in hypophysectomized rats

The existence of a circadian variation in the adrenocortical concentrations of cyclic AMP and cyclic GMP in male adult Wistar rats examined 10 days after hypophysectomy is demonstrated. The results suggest that the circadian variations of adrenocortical cyclic nucleotides observed previously in intact rats might not entirely depend upon pituitary corticotrophin.     

Circadian variation of adrenocortical cyclic nucleotides (cyclic AMP and cyclic GMP) in hypophysectomized rats

Summary The existence of a circadian variation in the adrenocortical concentrations of cyclic AMP and cyclic GMP in male adult Wistar rats examined 10 days after hypophysectomy is demonstrated. The results suggest that the circadian variations of adrenocortical cyclic nucleotides observed previously in intact rats might not entirely depend upon pituitary corticotrophin.Acknowledgment. Thanks are due to Prof. J. M. Racadot and Dr Y. Drouet for their assistance with the histological examinations.     

Activators of serum lipoprotein lipase in alloxan diabetic rats

Summary The amount of free fatty acid (FFA) liberated with intralipid in post-heparin guinea-pig serum, when serum from alloxan diabetic rat is incubated, is higher than that liberated when serum from healthy rats is used. The above effect is probably due to larger quantities of lipoprotein lipase present in the diabetic serum.     

Rapid effects of insulin on cyclic GMP location in an intact protozoan

We studied rapid changes in location of cyclic GMP inTetrahymena pyriformis. Insulin caused cGMP localization in cilia and near the plasma membrane (0.5–1 min). Later (1–5 min) cGMP localization was diffuse in cytoplasm with perinuclear accentuation. Inactive insulin analogs did not elicit these changes.     

Effects of N2, O2'-dibutyril cyclic GMP on the nucleoside phosphotransferase activity of the retina of the chick embryos.

In the retina of the chick embryo, 2 different forms of nucleoside phosphotransferase take part in the phosphorylation of thymidine. One is an unstable form with higher molecular weight. The other with lower m. wt is a stable form. This paper shows that N2,O2'-dibutyril cyclic GMP causes a marked decrement of the activity of the unstable nucleoside phosphotransferase.     

Elective induction in mice of solid and ascitic carcinoma of the exocrine pancreas by the repeated doses of antibodies against a lipoprotein lipase fraction]

Small doses, repeated for months of anti-esterase-lipoprotein antibodies, from several antisera raised against a crude lipoprotein-lipase from Rabbit adipose tissue (2), induce exocrine pancreatic carcinomas in mice, without any specific barrier. This seems to be the first case of a quite elective carcinogenic process of the pancreas, by an immunological mechanism, with a very high incidence, up to 100%. Such carcinomas are highly metastatic, produce a pancreatic carcinomatous ascites, and are deadly. This immunological pathogeny is discussed., more particulary on an action of immuno-complexes in an abnormal physiological environment.     

Rapid effects of insulin on cyclic GMP location in an intact protozoan.

We studied rapid changes in location of cyclic GMP in Tetrahymena pyriformis. Insulin caused cGMP localization in cilia and near the plasma membrane (0.5-1 min). Later (1-5 min) cGMP localization was diffuse in cytoplasm with perinuclear accentuation. Inactive insulin analogs did not elicit these changes.     

Metabolic activity of goat adipose tissue at the end of gestation and at the beginning of lactation: level of deoxyribouncleic acid content and lipoprotein lipase activity]

In the goat the passage from late pregnancy to early lactation is accompanied by a decrease of the epiploon lipoprotein lipase activity and an increase in the epiploon DNA content. The between-goat variations allow us to emphasize a linear relation between the lipoprotein lipase activity decrease and the reduction of the epiploon volume, expressed on a DNA basis. These parameters, used as indicators of the adipose tissue metabolic status, could contribue to the determination of a feeding strategy adapted to high yield milking Ruminants.