Oostatic hormone

M. domestica oostatic hormone seems to Inhibit the release or synthesis of egg development neurosecretory hormone (EDNH) (12), but in mosquitoes the hormone seems to act directly on the ovary (6). R, prolixus oostatic hormone, which has been partially purified (13), is a small peptide of M, 1,411 as determined on Sephadex G-50. Kelly et al. (5) prepared a crude extract of oostatic hormone from M, domestica, injected it into the autogenous mosquito Aedes atropalpus, and demonstrated inhibition of both egg development and ecdysteroid biosynthesis. They suggested that oostatic hormone functions at a point subsequent to release of EDNH. They were unable, however, to exclude the possibility that release of EDNH, itself, was inhibited. 

Oostatic hormone (nmol) Number of females Yolk length ( m SE)... 

Female A. aegypti were fed blood on a chicken, immediately injected with oostatic hormone, and 24 h later analyzed for egg development. M, of oostatic hormone was used as 1047.6 based on mass spectra analysis of the purified hormone for nmol calculations. 

Table III. Effect of Oostatic Hormone on Trypsin Synthesis in Decapitated and Ovariectomized Female Ae, aegypti...

Immediately decapitated and injected with oostatic hormone (1.45 nmol)... 

The synthetic peptide was then chromatographed using Cjg reversed phase HPLC. Native "oostatic factor" coeluted with the synthetic peptide indicating that "oostatic hormone" structure is NHj-Tyr-Asp-Pro-Ala-(Pro)j-COOH. A Corey-Pauling-Koltun (CPK) atomic model of the factor indicates that the carboxyl end of the molecule probably exhibits a left-handed helical conformation in solution due to the six proline residues (23). 

Model. Blood digestion plays a key role in the survival of vector arthropods and in the transmission of many important diseases such as malaria, dengue and Lyme disease (21.22). Collating these observations, a model for the control of trypsin biosynthesis in the mosquito is proposed. After the blood meal the midgut epithelial cells start to S3mthesize trypsin in concert with the neuroendocrine system that synthesizes oostatic hormone, as was proposed for Rhodnius by Davey and Kunster (11), which accumulates in the developing ovary as a prohormone. The... 

Table V. Effect of Synthetic Oostatic Hormone on Tr3rpsin Biosynthesis in Mosquitoes, Fleas, Flies and Sandflies...

Females were analyzed 24 h after the blood meal for [1,3-3H]DIP-trypsinlike derivatives. Oostatic hormone concentrations are based on M, 1047.6 derived from mass spectra analysis. 

Since the report of the existence of an oostatic hormone In the corpora lutea of BlPteHa aermanlca and grlgntaiig (D>... 

Oostatic Hormones inhibit ovarian maturation (Aea-TMOF) Aedes aegypti YDPAPPPPPP-OH 239... 

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