Specifity of the immunological inhibition of the parathyroid hormone activity

Résumé Des préparations hormonales de parathyroïde humaine, bovine et porcine furent traitées par des sérums anti PTH spécifiques et non spécifiques. Les expériences in vitro et in vivo ont montré que l'inhibition de l'activité biologique du PTH se produit seulement sous l'influence des sérums spécifiques. L'inactivation immunologique n'inhibe jamais complètement l'activité du PTH.     

Interaction of cortisol and epinephrine in the regulation of leucine kinetics in man

To assess the interaction of the two major stress hormones epinephrine and cortisol in the regulation of leucine kinetics in man, epinephrine (50 ng/kg/min) was infused either alone or in combination with cortisol (2 micrograms/kg/min) into two groups of 6 postabsorptive normal male subjects during 180 min. Plasma leucine concentrations decreased by 28% (p less than 0.05) from baseline during epinephrine treatment (plasma levels 515 pg/ml); this was due to a decrease of leucine appearance (determined by 1-13C-leucine infusions) by 23% (p less than 0.025); leucine oxidation decreased by 29% (p less than 0.05). However, when plasma cortisol concentrations were elevated to supraphysiological levels (16.3 mumol/l) during epinephrine administration, the decreases of leucine plasma concentrations, appearance and oxidation were abolished. Plasma glucose and FFA concentrations were similarly elevated during both kinds of treatment. Since leucine appearance represents a measurement of total body protein breakdown and leucine disappearance into non-oxidative pathways reflects protein synthesis, the data indicate that plasma epinephrine concentrations during severe stress exert a protein anabolic effect in man which may counteract catabolic properties of elevated plasma cortisol.     

Circadian and seasonal rhythm in stimulation-produced analgesia

Summary The antinociceptive effect induced in mice by peripheral electrical stimulation has been shown to exhibit both circadian (24 h) and seasonal (1 year) rhythms. These findings contribute to an explanation of the variability reported for stimulation-produced analgesia.     

Fe(II)-induced decomposition of epidioxides. A chemical model for prostaglandin E,prostacyclin and thromboxane biosynthesis

Summary A chemical model for biosynthesis of PGE, PGX and the thromboxanes from the prostaglandin endoperoxides is presented which is based on known reactions of other endoperoxides with the Fe(II)–Fe(III) redox system in vitro.Supported in part by USPH grant CA-13121 through the National Cancer Institute.