GLORIA

GEOMAR Library Ocean Research Information Access

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Archives of Insect Biochemistry and Physiology 10 (1989), S. 303-316 
    ISSN: 0739-4462
    Keywords: juvenile hormone metabolites ; L-[14C]methionine incorporation ; Chemistry ; Food Science, Agricultural, Medicinal and Pharmaceutical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Corpora cardiaca-corpora allata (CC-CA) from vitellogenic females of Nauphoeta cinerea degraded, in vitro, racemic and (10R)-juvenile hormone III (JH III) at a rate of 249 pmol/CC-CA/h and 786 pmol/CC-CA/h, respectively. The major metabolite formed was JH III acid, together with some highly polar products. CC-CA homogenates degraded racemic JH III to a small extent, whereas (10R)-JH III was degraded efficiently to JH III acid. No highly polar products were formed by CC-CA homogenates. When CC-CA were incubated with racemic JH III acid, some of this substance was degraded to highly polar products, and a minor part was methylated to JH III. CC degraded very little JH III acid and did not methylate it to JH III. CC-CA homogenates methylated JH III acid very efficiently; we measured an apparent Kmax of 37.8 μM and a Vmax of 1,260 pmol/4 h/ CC-CA equivalent. The addition of JH III acid to CC-CA in vitro increased the rate of biosynthesis of JH III, as determined by measuring incorporation of methyl[14C]methionine into JH III. These data indicate that the metabolite JH III acid can enter the CA and be methylated to JH III.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Archives of Insect Biochemistry and Physiology 10 (1989), S. 317-331 
    ISSN: 0739-4462
    Keywords: Chemistry ; Food Science, Agricultural, Medicinal and Pharmaceutical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: In vitellogenic females of Nauphoeta cinerea, injected (10R)-juvenile hormone (JH) III was degraded more rapidly than racemic JH III: we measured a half-life of 21 min (with or without coinjection of lipophorin) for the former and 24 min (with coinjection of lipophorin) and 43 min (without coinjection of lipophorin) for the latter. One to two hours after injection, JH III acid was the major metabolite observed; in addition, several highly polar products were found. The half-life of injected racemic JH III acid was 19 min with coinjection of lipophorin and 4 min without. The JH III acid titer in hemolymph was low (around 5-10 pmol/ml) in last instar larvae and previtellogenic and pregnant females and reached higher values (40-100 pmol/ml) in vitellogenic and ovulating females. Racemic JH III acid could be methylated in vitro to JH III by corpora cardiaca-corpora allata (CC-CA) from penultimate instar larvae and females at stages between adult ecdysis and ovulation and at the very end of pregnancy, but not by CC-CA from last instar larvae and adult females at earlier stages of pregnancy. This indicates that CC-CA are capable of methylating JH III acid only at stages when JH III is detectable in the hemolymph. In double-labelling experiments with CC-CA from vitellogenic females and L-[14C]methionine and [3H]JH III acid as precursors, we observed that only a small proportion (1-8%) of total biosynthesized JH III was derived from JH III acid when the latter was present at physiological concentration. This suggests that in vivo recycling of JH III acid by CC-CA plays only a minor role in the regulation of the titer of JH III and JH III acid.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...