Ecdysone metabolism in premolt land crabs (Gecarcinus lateralis)

Journal Article · Fri Jan 01 04:00:00 EST 1982 · Gen. Comp. Endocrinol.; (United States)

DOI:https://doi.org/10.1016/0016-6480(82)90239-8· OSTI ID:6098067

McCarthy, J F

The metabolic fate of (/sup 3/H)ecdysone was examined in land crabs (Gecarcinus lateralis) in premolt stages D/sub 1/ (late)-D/sub 2/ and D/sub 3/ to elucidate changes in biochemical pathways and dynamics of ecdysteroid metabolism during proecdysis. In crabs of both premolt stages, 20-hydroxyecdysone was the principal metabolite (85 to 95% of the recovered radioactivity); further hydroxylation to 20,26-dihydroxyecdysone and formation of polar conjugates (primarily in the midgut gland) occurred to a limited extent. The rate of elimination of (/sup 3/H)20-hydroxyecdysone was slow in crabs of both premolt stages (k approx. 0.006 to 0.009 hr/sup -1/; t/sub 1/2/ approx. 77 to 115 hr). Serum titers of 20-hydroxyecdysone (measured by radioimmunoassay) increased during stages D/sub 0/ to D/sub 2/ and maintained a maximum level of 100 ng/ml for a week (stage D/sub 2/-early D/sub 3/) before dropping rapidly to intermolt levels during the last day before ecdysis (stage D/sub 3/ to D/sub 4/). The rapid decrease in serum titers results from a 10-fold increase in the rate of elimination of serum ecdysteroids at about 24 to 48 hr before ecdysis. The titer of an apolar ecdysteroid, tentatively identified as ponasterone. A, increases rapidly during stages D/sub 1/ and D/sub 2/ to levels several-fold higher than the maximum titers of 20-hydroxyecdysone. Ponasterone A titers then decreased very rapidly during the last 3 days before ecdysis (stages D/sub 3/ and D/sub 4/).

• Research Organization: Oak Ridge National Lab., TN
• DOE Contract Number: W-7405-ENG-26
• OSTI ID: 6098067
• Journal Information: Gen. Comp. Endocrinol.; (United States), Journal Name: Gen. Comp. Endocrinol.; (United States) Vol. 47; ISSN GCENA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ANIMALS
AQUATIC ORGANISMS
ARTHROPODS
BIOLOGICAL PATHWAYS
BLOOD SERUM
CRUSTACEANS
DATA
EXPERIMENTAL DATA
INFORMATION
INVERTEBRATES
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
METABOLISM
METABOLITES
MOLTING
NUMERICAL DATA
ORGANIC COMPOUNDS
QUANTITY RATIO
RADIOASSAY
RADIOIMMUNOASSAY
STEROIDS
TIME DEPENDENCE
TRACER TECHNIQUES
TRITIUM COMPOUNDS