Activity of orotate metabolizing enzyme complex and various urea-cycle enzymes in mutant mice with ornithine transcarbamylase deficiency

Summary The overall activity of the enzyme complex consisting of orotate phosphoribosyl transferase and orotidine monophosphate decarboxylase, and of various enzymes of the urea cycle, has been studied in sparse-fur (spf) mutant mice with ornithine transcarbamylase deficiency. The enzyme complex has a lower overall activity, which could be caused by disturbed pyrimidine metabolism due to hyperammonemia. Other enzymes of the urea cycle do not show any significant change.Acknowledgments. The research was supported by a grant from the Conseil des Clubs Sociaux and Fondation Justine Lacoste Beaubien, Montréal. The authors wish to thank Ms Louise Poulin and Ms Francine Poisson for technical assistance.     

Lipid and phospholipid content and fatty acid composition of the chick lung during embryonic development.

The evolution of total phospholipid, phosphatidylcholine and phosphatidylethanolamine content of chick lung during embryonic development is in good agreement with morphological data. Saturated fatty acids are predominant. A sex-linked difference is observed in the evolution of phosphatidylcholine.     

Role of the Raphe Magnus nucleus in morphine analgesia : studies with intracerebral microinjections in the rat]

Microinjections of low concentration of morphine (5 micrograms) into the nucleus Raphé Magnus of the Rat produce a strong analgesia that can be reversed by systemic naloxone, an opiate antagonist. The administration of naloxone (5 micrograms) into the Raphé Magnus considerably reduces the effects of intravenous morphine. The effects of microinjections of morphine are strongly reduced by Cinanserin, suggesting a role for serotoninergic mechanisms in morphine analgesia.     

Adaptation of the pituitary gland to prolonged LRH stimulation

Summary With prolonged constant rate infusion of luteinizing hormone-releasing hormone (LRH), the LH secretion rate of the rat pituitary gland changes continuously until a steady state of relative desensitization has developed. Recovery from this state can occur independently from changes in the pituitary's LH content.