Cyclic AMP during development and ageing of the insectCeratitis capitata

Summary Cyclic AMP was determined during the development of the dipteraCeratitis capitata. The concentration of the nucleotide reaches a peak at apolysis with a sharp decline in the pharate adult stage. A gradual increase takes place through the longevity of adult stage reaching a maximum plateau at the end of life.We are indebted to Prof.A. M. Municio for advice and encouragement and Mr.V. G. Corces for technical assistance.     

Interaction between the soluble and particulate neuraminidases of chick liver

Summary The sum of the neuraminidase activities found in the isolated soluble and particulate fractions of chick liver was considerably higher than that observed in the cytoplasmic extract from which these fractions were obtained. Addition of increasing amounts of particulate neuraminidase to a constant amount of the soluble preparation resulted in a progressive loss of enzyme activity.This investigation was supported in part by U. S. Public Health Service Grant NS09176 from the National Institutes of Health.     

Allantoinase in the marine polychaeteEudistylia vancouveri

Summary Allantoinase, an enzyme in the purine-urea cycle, was found inEudistylia vancouveri (Polychaeta). The enzyme had a pH optimum at 7.6 TheK _m was 0.012M allantoin, and the Arrhenius energy of activation was 12.6 to 14.6 kcal/mol.Supported by the U. S. National Science Foundation (Institutional Grant) and by the U. S. Environmental Protection Agency Grant No. T-900204 (WP-175). Publication No. 10 of the Laboratory of Biochemical Ecology; College of Fisheries Contribution No. 458. We thank Dr.Robert L. Fernald for generously making available to us the facilities of the Friday Harbor Laboratories, Friday Harbor, Washington.     

Increased erythrocyte permeability to Li and Na in the spontaneously hypertensive rat

Summary Red blood cells incubated in a physiological medium in which Li replaces Na (LiPSS) gain Li in exchange for Na and K. The rate of Li uptake is modestly but significantly increased in the spontaneously hypertensie rat (SHR) at 37°C and at 22°C. The slow rate of Na gain and K loss during cooling at 2°C was about doubled in unmodified whole blood samples from the SHR.This work was carried out with the aid of a grant from the British Columbia Heart Foundation.     

The effect of oxine-5-sulphonic acid on the hepatic drug metabolism in the rat

Summary Oxine-5-sulphonic acid inhibits the metabolism of aminopyrine in the rat liver in vitro. The characteristics of this inhibition vary according to whether the oxidativeN-demethylation of the substrate is determined by the formation of the metabolite 4-aminoantipyrine or by the production of formaldehyde.     

Timing of single daily meal influences relations among human circadian rhythms in urinary cyclic AMP and hemic glucagon,insulin and iron

Summary Relations among circadian rhythms in serum iron, glucagon and insulin and urinary cyclic AMP excretion differ drastically when diurnally active, nocturnally resting human adults consume all daily food for one week as breakfast only and for another week as dinner only—a finding of interest to diverse fields, e.g., for optimizing certain kinds of therapy or for a better utilization of calories.Supported by grants (No. RR-400 from the General Clinical Research Centers Program of the Division of Research Resources, National Institutes of Health, USPHS and Nos. 5-K6-GM-13, 981 and 1RO1-CA-14445-01) and grant No. 20, Fondation de l'industrie pharmaceutique pour la recherche.     

A new substrate for cultures of dissociated primary rat brain

Different substrates were used to coat plastic petri dishes for the cultivation of dissociated fetal rat brain cells. Only on surfaces which were coated with a mixture of serum and non-reconstituted collagen, did the majority of the inoculated cells attach singly or as aggregates within 24 h. The attachment of the cells was followed by the outgrowth of cellular processes either from single cells or from aggregates in the same time period. This did not occur on collagen or serum treated or on regular plastic dishes. Under the latter conditions a similar outgrowth was observed only after 3–5 days.