ACTH-like material

Rafaeli et ai. have recently reported the existence of an adrenocorticotropin (ACTH)-like material in locust CC (5.) detectable by immunoassay. They also reported that ACTH at 10 mM stimulated liquid excretion from, and elevated levels of cAMP in, locust Malpighian tubules. Extracts of CC produced similar effects in the traditional in vitro assay (fi.). They believe that a diuretic peptide in locusts has at least immunological similarity to ACTH. While the partial sequence reported (4.) by Morgan et ai. has no apparent similarity to ACTH, it is conceivable that these groups could be investigating the same factor. 

Figure 7. ACTH-like material in Tetrahymena pyriformis. (bottom panel) , the extract x, synthetic human ACTH standard O, anti-ACTH antiserum , Sepharose-protein A immunodepletion. (Reproduced from Ref. 5).

Acetoxy displacement, cephalosporin C, I68,l69f ACTH-like material... 

In another study, a substance with CRF activity was isolated from sheep hypothalami by means of gel filtration and ion-exchange chromatography [289]. The substance, whose structure remains to be determined, has no pressor or ACTH-like activity and is believed to be a single chemical entity. However, the material was not subjected to countercurrent distribution which may separate the 2 CRF activities and thus the possibility of a second CRF cannot be disregarded. Chan, Schaal and Saffran [290] demonstrated two CRF s in rat median eminence tissue, a large and a small CRF. They suggested that the... 

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