Biosynthesis of ecdysteroids from cholesterol by crab Y-organs, and eyestalk suppression of cholesterol uptake and secretory activity, in vitro

Academic Article

Abstract

  • Precursor incorporation studies were conducted in vitro with activated Y-organs from 48-hr de-eyestalked Cancer antennarius donors. When the glands were prelabeled in vivo by systemic injection of [ H]cholesterol 12 hr prior to removal, and subsequently incubated 24 hr in label-free medium, the glands secreted H-labeled ecdysone. The glands also secreted an unidentified ecdysteroid with comigrating H-label with characteristic retention time on normal-phase HPLC of 4 min (4-min unknown). The compound is less polar, and is secreted in a quantity and apparent specific activity approximately fivefold greater, than ecdysone. Compared with chromatographic retention times and competitive binding curves of authentic standards, the 4-min unknown was determined not to be ponasterone A, inokosterone, makisterone, or several other possible products or intermediates. In contrast with Y-organs from intact donors, those from de-eyestalked crabs exhibit gretly increased cholesterol uptake and secretion of both ecdysone and 4-min ukknown in vitro. All three responses were suppressed in dose-dependent manner by eyestalk extract in the dose range, 1-4 eyestalk equivalents/Y-organ. Secretion of 4-min unknown was the response most sensitive to eyestalk extract (requiring the least dose for 50% inhibition. © 1985. 3 3 3
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    Digital Object Identifier (doi)

    Author List

  • Watson RD; Spaziani E
  • Start Page

  • 140
  • End Page

  • 148
  • Volume

  • 59
  • Issue

  • 1