Activity-induced thermogenesis in lean and genetically obese (ob/ob) mice

Summary Motor activity was approximately 60% lower in genetically obese than in lean mice, during three consecutive hours at thermal neutrality. It is suggested that this must have contributed to the lower heat production measured in the obese mice and that activity-induced thermogenesis contributes significantly to differences in energy expenditure between the genotypes, at least in the short-term.     

Activity-induced thermogenesis in lean and genetically obese (ob/ob) mice

Motor activity was approximately 60% lower in genetically obese than in lean mice, during three consecutive hours at thermal neutrality. It is suggested that this must have contributed to the lower heat production measured in the obese mice and that activity-induced thermogenesis contributes significantly to differences in energy expenditure between the genotypes, at least in the short-term.     

Stimulation of locomotor activity of genetically obese mice by amphetamine

Zusammenfassung Die motorische Aktivität von genetish obesen (ob/ob) und diabetischen (db/db) Mäusen wurde durchd-Amphetamin stärker gesteigert als bei normalen Mäusen, wobei das Regulationszentrum für die motorische Aktivität intakt zu sein scheint.     

Altered brain cholinergic enzymes activity in the genetically obese rat

Summary Genetically obese male Zucker rats (fa/fa) and their lean littermates (Fa/-) were used in this experiment. Fourteen-week-old obese and lean littermates were sacrificed and choline acetyltransferase (ChAT) and acetylcholinesterase (AChE) enzymes were assayed in specific brain regions. The assays of these enzymes indicate that obese animals and a significantly lower ChAT activity in the cerebellum, pons, and cerebral cortex and a significant increase in ChAT activity in the thalamus and hypothalamus. Meanwhile, the cerebral cortex, cerebellum, midbrain, thalamus and hypothalamus of the obese animals showed significantly higher AChE activity than their lean littermates. It was concluded from this study that obesity may be associated with changes in the enzymes of the brain cholinergic system.This work was supported by a grant from the National Aeronautics and Space Administration (NAG 2-411), a grant from the National Institutes of Health (NIH RR 0811), and a grant from the Division of Research Resources, National Institutes of Health (NIH Grant RR 03020).     

Dissociation of obesity,hypercholesterolemia and diabetes from atherosclerosis in ob/ob mice

Summary Genetically obese, diabetic and hypercholesterolemic C57BL/6J-ob/ob mice were placed on Purina Laboratory Chow containing 2% cholesterol for up to 4 months. They developed higher plasma cholesterol levels and accumulated an increased quantity of cholesterol in the liver but failed to develop atherosclerotic lesions in the aorta as would be expected in an obese, diabetic and hypercholesterolemic human adult.Acknowledgments. We wish to thank Mr. Willis M. Overton for his excellent technical assistance.     

Altered brain cholinergic enzymes activity in the genetically obese rat

Genetically obese male Zucker rats (fa/fa) and their lean littermates (Fa/-) were used in this experiment. Fourteen-week-old obese and lean littermates were sacrificed and choline acetyltransferase (ChAT) and acetylcholinesterase (AChE) enzymes were assayed in specific brain regions. The assays of these enzymes indicate that obese animals had a significantly lower ChAT activity in the cerebellum, pons, and cerebral cortex and a significant increase in ChAT activity in the thalamus and hypothalamus. Meanwhile, the cerebral cortex, cerebellum, midbrain, thalamus and hypothalamus of the obese animals showed significantly higher AChE activity than their lean littermates. It was concluded from this study that obesity may be associated with changes in the enzymes of the brain cholinergic system.     

Colony promoting activity and its target 'pre-CFUc' in genetically anemic mice of W/Wv genotype

Incubation of bone marrow cells with supernatant from long-term cultures of bone marrow cells increases the number of granulocyte-macrophage progenitor cells. This study reveals the presence of target cells of the colony promoting activity (CPA) in W/Wv mouse marrow. It is also shown that CPA does not stimulate erythroid colony formation in vitro.     

Increase in activity of natural killer cells (NK cells) by serum thymic factor]

The serum thymic factor (FTS) and one of its structural analogues have been administered to adult normal Mice for 2 to 12 weeks. This treatment induced a significant increase in spleen cell natural killer (NK) activity, evaluated by a cytotoxicity assay against YAC cells.     

Increase of interferon antiviral activity by exogenous cyclic adenosine-3′∶5′-monophosphate (cAMP)

Summary Some effects of cAMP on replication of Semliki Forest Virus in chick embryo fibroblast cell cultures are described. Depending on concentration, the incorporation of [³H]-uridine into viral RNA or the formation of plaqueforming units is inhibited; the highest concentration tested was 8 mM. Cyclic AMP has an effect of its own and increases the Interferon action in the lower concentration ranges of Interferon (up to 1 unit/ml). The effect of cyclic AMP is fast, needs no induction and is also visible in late phases of viral replication. However, these experiments do not establish a causal relation between cAMP and Interferon.Work supported by the Swiss National Science Foundation, grants 3.1050 and 3.540.     

Increase in the non-specific resistance to infection in mice after oral administration of 2 synthetic glycopeptides with adjuvant activity]

Two synthetic glycopeptides (MurNAc-L-Ala-D-isoGln and MurNAc-L-Ala-D-Glu), having adjuvant activity, were shown to enhance non-specific resistance to infection against K. pneumoniae. These compounds were active by various routes including oral administration and even if administered after the challenge. Two steroisomers lacking adjuvant activity did not protect the infected Mice.