On the origin and metabolic fate of α-ecdysone in insects
TL;DR: The conversion of α- to β-ecdysone occurs efficiently in isolated abdomens of Calliphora and Bombyx, thus indicating that the ecdysial gland may not be the site of this conversion, and that the observed hormonal effect of β-ECDysone may be due in part to its prior metabolism to α-ecdYSone.
About: This article is published in General and Comparative Endocrinology.The article was published on 1970-08-01. It has received 124 citations till now. The article focuses on the topics: Bombyx.
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TL;DR: The titer of ecdysone in whole animal extracts of Manduca sexta was determined by radioimmunoassay during the fifth (last) larval instar, pharate pupal development and pupation as discussed by the authors.
265 citations
TL;DR: Developmental correlations suggest that the sterol 7,8-dehydrogenase and terminal hydroxylases in Manduca prothoracic glands are not regulated by protharacicotropic hormone, in contrast to the utilization of 7- dehydrocholesterol in crustaceans, which is influenced by molt inhibiting hormone.
184 citations
TL;DR: Cells of a diploid line established from embryos of Drosophila melanogaster, and maintained in the laboratory for more than 3 years, respond specifically to the synthetic moulting hormones α-ecdysone and β-ecdYSone and to several ecdysone analogues.
164 citations
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TL;DR: It has been shown that in the presence of a NADPH2-generating system prostatic nuclei convert testosterone to dihydrotestosterone, whereas prostatic cytoplasm reduces dihydotestosterone to androstandiol.
985 citations
TL;DR: Aus Seidenspinner-Puppen wurde durch Methanolextraktion und Anreicherung in Bezug auf das im Test am abgeschnürten Abdomen von Calliphora-Larven wirksame Prinzip ein kristallisierter einheitlicher Stoff vom Schmp. 235-237° erhalten, der im calliphora test with 0,0075 γ wirkksam ist as mentioned in this paper.
Abstract: Aus Seidenspinner-Puppen wurde durch Methanolextraktion und Anreicherung in Bezug auf das im Test am abgeschnürten Abdomen von Calliphora-Larven wirksame Prinzip ein kristallisierter einheitlicher Stoff vom Schmp. 235—237° erhalten, der im Calliphora-Test mit 0,0075 γ wirksam ist. Wie Versuche an Saturniiden-Puppen (C. M. Williams) zeigten, handelt es sich um das Hormon der Prothorakaldrüsen.
282 citations
TL;DR: In this article, the vollstandige Struktur und Konfiguration des Insektenverpuppungshormons Ecdyson wird durch Rontgenstrukturanalyse der naturlichen, schweratomfreien Verbindung als 2β.3β.14α.22βF.25-Pentahydroxy-Δ7-5β-cholestenon-(6) ermittelt.
Abstract: Die vollstandige Struktur und Konfiguration des Insektenverpuppungshormons Ecdyson wird durch Rontgenstrukturanalyse der naturlichen, schweratomfreien Verbindung als 2β.3β.14α.22βF.25-Pentahydroxy-Δ7-5β-cholestenon-(6) ermittelt.
187 citations
TL;DR: The role of the blood is to serve, not as a reservoir, but as a pipeline through which ecdysone flows from the ring-gland to its sites of action and swift inactivation, which can account for its low titer in both the blood and tissues.
Abstract: 1. Ecdysone is in a highly dynamic state after its injection or its secretion by the ring-gland of Sarcophaga peregrina. Hormonal activity is rapidly destroyed by an inactivating mechanism which is present in the tissues but not in the blood.2. Inactivation is blocked by low temperatures or anaerobic conditions—a finding that implicates chemical and, more particularly, oxidative reactions. The mechanism in question could be demonstrated in larval fragments but not in crude or fractionated homogenates.3. When injected into mature larvae, 1 µg of α-ecdysone loses 50% of its activity in 1 hour and 98% in 8 hours. Lower doses show even briefer "half-lives."4. The rapid inactivation of ecdysone can account for its low titer in both the blood and tissues. Thus at the "critical period" for puparium formation, the entire larva contains only 2.5 nanograms, corresponding to only 7% of a Sarcophaga unit.5. The evidence points to the accumulation, not of the hormone itself, but the covert biochemical and biophysical ...
162 citations