Insect hormones in vertebrates: Anabolic effects of 20-hydroxyecdysone in Japanese quail

Ecdysteroids are hormones controlling cell proliferation, growth and the developmental cycles of insects and other invertebrates¹. They are occasionally present in various unrelated plants for no apparent reason; no phytohormonal function has yet been identified. In certain cases, ecdysteroids are accumulated to high levels in leaves, roots or seeds. Some ecdysteroid-containing plants have been known as medicinal plants for centuries. One of them,Leuzea carthamoides Iljin (Asteraceae), growing in Central Asia, contains 0.4% ecdysteroid in dry roots and 2% in seeds. A pharmacological preparation from this plant, Ecdisten, is already available as a commercial preparation for its anabolic, tonic and other effects, for medical use (review²). It remained problematic, however, whether ecdysteroids were truly responsible for these effects, becauseLeuzea contains a number of other biologically active compounds in addition to ecdysteroids. We extracted and purified ecdysteroids from the seeds ofLeuzea. With 6 g of 96% 20-hydroxyecdysone (20E), we made a large-scale feeding assay with Japanese quail to find out whether ecdysteroid alone could duplicate the anabolic effects of the seeds. We found that the 96% ecdysteroid increased the mass of the developing quails in a dose-dependent manner, with the rate of increase proportional to the ecdysteroid content in the seeds; there was a 115% increase in living mass with 100 mg kg^–1 of pure 20E compared with 109.5% increase with 100–180 mg kg^–1 20E equivalents in the seeds. We conclude that the plethora of growth-promoting, vitamin-like effects induced in vertebrates byLeuzea is mediated by ecdysteroids.     

Ecdysteroid titers during larval reproduction of the dipteran insectHeteropeza pygmae

Summary Ecdysteroid titers were measured in whole-body extracts of pedogenetically reproducing larvae of the dipteran insectHeteropeza pygmaea and in the dietary fungus. The titers are very low in the first 3 days of larval growth, but increase during the last 2 days. The level of 20-hydroxyecdysone is then significantly higher than that of ecdysone. Measurements of the titers in the fungus gave no conclusive results.Supported by the Swiss National Science Foundation, grants No. 3.218-0.77 to D.F.W. and 3.714-0.80 to B.L. We thank Xiang-Xiong Zhu for help with the RIA and Mrs G. Rhyner for technical assistance. Gifts of ecdysone antiserum from Dr J. D. O'Connor and of 23,24-[³H₂]-ecdysone from Dr J. Koolman are also gratefully acknowledged.     

Level of ecdysteroids in the hemolymph of the freshwater prawn,Macrobrachium rosenbergii (Crustacea: Decapoda) in relation to the phenomenon of cheliped autotomy in males

Summary Ecdysteroid titers were determined in the hemolymph of adult freshwater prawn,Macrobrachium rosenbergii, during various stages of the molt cycle, using radioimmunoassay. A comparison was made between hormone levels in males which undergo normal molt and dominant males of the population which periodically commit cheliped autotomy. The latter is a recently discovered phenomenon whereby a male voluntarily sheds off both its long claws at molt, once the ratio between body length and combined claw length reaches a ceiling level of about 13. Shortly before an autotomizing molt, hormone levels were about three times higher than on the eve of a normal molt.10 November 1986     

Makisterone A and 24-methylenecholesterol from the ovaries of the honey bee,Apis mellifera L

Summary Makisterone A, a 28-carbon ecdysteroid (molting hormone) has been isolated from the ovaries of queen bees. Analysis by reversed-phase and silica high performance liquid chromatography (HPLC) in conjunction with a radioimmune assay (RIA) revealed about 11 ng of makisterone A present per gram of ovaries on a fresh weight basis. No C₂₇ ecdysteroids were detected. The predominant neutral sterol present was 24-methylenecholesterol.     

Ecdysteroids in the pupae of Opogona sacchari （Bojer）, a new invasive alien pest

The banana moth Opogona sacchari (Bojer) of the family Hieroxestidae is a new invasive alien pest in China that originated from the moist tropical and sub- tropical areas of Africa[1]. So far, the pest has dispersed to many areas around the world includin…     

Titers of ecdysone, 20-hydroxyecdysone and juvenile hormone III throughout the life cycle of a hemimetabolous insect,the ovoviviparous cockroachNauphoeta cinerea

Summary Titers of ecdysone, 20-hydroxyecdysone and juvenile hormone III were measured in whole body extracts or hemolymph of embryos, first, penultimate and last stadium nymphs, and adult females ofNaupoheta cinerea. We used a gas-chromatography/mass spectrometry method for quantifying juvenile hormone and a radio-immunoassay for ecdysteroid determination. Juvenile hormone III is particularly abundant in the embryonic stage (up to 960 ng/g), at a low level in first and penultimate stadium nymphs (2–10 ng/ml) and almost absent in the last nymphal stadium; in the adult female the juvenile hormone titer rises to 180 ng/ml in hemolymph during rapid oocyte growth. The titers of ecdysone and 20-hydroxyecdysone undergo similar fluctuations in the embryonic and nymphal stages, being highest at the time of cuticle formation in the embryo and a few days before the nymphal and adult molts (around 100–200 ng/ml for exdysone and 2–4 g/ml for 20-hydroxyecdysone).Acknowledgments. We thank Mrs A. Tschan for rearing the cockroaches, Mr M. Kaltenrieder for drawing the graphs, Mr G.C. Jamieson and Mrs C. Reuter for GC/MS analyses. We are also grateful to the Swiss National Science Foundation (grant no. 3.291-0.82 to B. Lanzrein) and the United States National Science Foundation (grant no. PCM 82-08665 to D.A. Schooley) for their financial support.