Occurrence of hibernation in the golden hamster,Mesocricetus auratus waterhouse

Résumé Une hypothèse est présentée pour expliquer la variabilité en durée de la période préléthargique au cours de l'année. La période préléthargique pouvait être approximée à trois mois. Dès novembre, le Hamster développe une prédisposition, résultant dans un raccourcissement de la période préléthargique. En février, la prédisposition pour le sommeil hivernal est au maximum, mais ensuite elle est perdue.     

Aneuploidy as a consequence of senescence and ovariectomy in the golden hamster (Mesocricetus auratus)

The hypothesis of the preferred X-chromosome loss in elder human females was reevaluated in the golden hamster: early castration of females proved that the increase of aneuploid cells is correlated with the loss of the ovaries. But here, and in old females, aneuploidy consisted of random loss of excess of chromosomes, in no case an X-chromosome.     

Aneuploidy as a consequence of senescence and ovariectomy in the golden hamster (Mesocricetus auratus)

Summary The hypothesis of the preferred X-chromosome loss in elder human females was reevaluated in the golden hamster: early castration of females proved that the increase of aneuploid cells is correlated with the loss of the ovaries. But here, and in old females, aneuploidy consisted of random loss or excess of chromosomes, in no case an X-chromosome.     

Profound hypothermia in golden hamsters (Mesocricetus auratus) induced by serotonergic potentiating and noradrenergic inhibiting drugs

Profound hypothermia (6 degrees C) was induced in cold exposed golden hamsters (Mesocricetus auratus) by a combination of drugs that potentiate brain serotonergic activity (fluoxetine and pargyline) and inhibit noradrenergic activity (alpha-methyl-p-tyrosine). Individual drugs and combinations of 2 were ineffective.     

Profound hypothermia in golden hamsters (Mesocricetus auratus) induced by serotonergic potentiating and noradrenergic inhibiting drugs

Summary Profound hypothermia (6°C) was induced in cold exposed golden hamsters (Mesocricetus auratus) by a combination of drugs that potentiate brain serotonergic activity (fluoxetine and pargyline) and inhibit noradrenergic activity (alpha-methyl-p-tyrosine). Individual drugs and combinations of 2 were ineffective.Acknowledgements. We acknowledge the support of a research grant PCM74-05158 A01 to A.H.M. from the National Science Foundation (USA) and thank Lilly Research Laboratories, Indianapolis, Indiana, for the gift of fluoxetine (Lilly 110140).     

Complete development ofAncylostoma ceylanicum (Looss, 1911) in golden hamsters,Mesocricetus auratus

Zusammenfassung Es gelang, den HakenwurmAncylostoma ceylanicum an den Goldhamster zu adaptieren, was zur Vereinfachung chemotherapeutischer Versuche bei der Bekämpfung dieses tierischen und menschlichen Parasiten im Laboratorium beitrug.     

Effects of ovariectomy on the oxidative metabolism of the central nervous system and adrenal glands in female hamster (Mesocricetus auratus)

Summary We have studied the influence of ovariectomy on the oxidative activity of hypophysis, hypothalamus, posterior cortex, septal area, amygdala and adrenal glands, in female hamsters, because their neuroendocrine behavior seems to differ from that of rats. Our results show a decreasing the O₂ uptake in the hypothalamus and adrenal glands and an increase in the rest of the structures.     

Effects of ovariectomy on the oxidative metabolism of the central nervous system and adrenal glands in female hamster (Mesocricetus auratus)

We have studied the influence of ovariectomy on the oxidative activity of hypophysis, hypothalamus, posterior cortex, septal area, amygdala and adrenal glands, in female hamsters, because their neuroendocrine behavior seems to differ from that of rats. Our results show a decreasing the O2 uptake in the hypothalamus and adrenal glands and an increase in the rest of the structures.     

Oxidative activity during the sexual cycle of the central nervous system,adrenal glands and ovaries in the hamster (Mesocricetus auratus)

Summary The results indicate significant increases of the oxidative metabolism in the oestrus of the ovaries, hypothalamus and the posterior cortex, while in the amygdala this increase occurs in the phase of diestrus.     

Inhibition of potassium (86Rb) influx in Ehrlich ascites cells by bilirubin and ouabain

Summary Bilirubin inhibited influx of potassium into Ehrlich ascites cells without altering efflux. The data showed that compared with ouabain, net potassium influx components were impaired in a higher degree by bilirubin. The reversal of this effect was shown, in our experimental conditions, only for ouabain.Acknowledgments. This work was supported by a grant from the Consejo Nacional de Investigaciones Cientificas y Técnicas, República Argentina. The authors wish to thank Miss Marta S. Göthje for techical assistance.     

The role of distinct membrane components of the enzyme in the ouabain sensitivity of Na+/K+ ATPase]

Purified plasma membranes from a cell line derived from the murine plasmocytoma MOPC 173 exhibited a 50% inhibition of the Na+K+ ATPase by 120 muM ouabain. EDTA treatment of such membranes induced a drop in the ouabain concentration needed for 50% inhibition to 0.4 muM. Supernatants obtained after EDTA treatment were able to complement with Ca(++) + Mg++ the washed EDTA treated membranes which recover their original resistance.