Molt-inhibiting hormone

Chung JS, Webster SG (2005) Dynamics of in vivo release of molt-inhibiting hormone and crustacean hyperglycemic hormone in the shore crab, Carcinus maenas. Endocrinology 146 5545-5551... 

Although It Is unknown how azadlrachtln acts as an ecdysis Inhibitor, It apparently does not act by Inhibiting chitln synthetase (32). Possibly, ecdysis Inhibition Is caused by a disruption of the tltre of ecdysterone (40, 44) or by an Interference with the neuroendocrine system, prothoradcotroplc hormone and allatotroplc hormone, which controls the tltres of molting hormone and juvenile hormone, respectively (45). 

The probability that nematode endocrine control involves some compounds similar in structure to vertebrate or insect steroid hormones has prompted several investigations of the effects upon nematodes of exogenous application of various concentrations of several of these compounds (53-62). When observed, effects have consisted primarily of inhibition or stimulation of growth, reproduction or molting. Although the high concentrations of added steroid or the nature of the assey system in some of these experiments might lead to speculation about the in vivo extrapolation of such results, the bo<(y of work is compatible with the hypothesis that steroids are hormonally active within nematodes. 

Robbins, W. E., J. N. Kaplanis, M. J. Thompson, T. J. Shortino, and S. C. Joyner, Ecdysones and synthetic analogs Molting hormone activity and inhibitive effects on insect growth, metamorphosis, and reproduction. Steroids, 16, 105-125 (1970). 

Two hormones known to regulate insect metamorphosis and development are the juvenile hormones and 20-hydroxyecdysone. Juvenile hormone inhibits progress toward the adult form and 20-hydroxyecdysone is the driving force for molting. For 20 years juvenile hormone agonists have been the subject of intensive chemical research providing several new insecticides, including methoprene and kinoprene (2). 

The hormone that inhibits molting is methyl famesoate, which is very similar to the juvenile hormone of insects it inhibits the functioning of the Y organ between two successive molts. In insects this second hormone is... 

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