Methanol extracts of the skin of Hyla caerulea, an Australian frog, contain a principle which displays a conspicuous hypotensive effect in the dog and other experimental animals and possesses a formidable stimulant action on some extravascular smooth muscles and on certain secretions, especially those of gastric and pancreatic juice (Erspamer, Bertaccini, De Caro, Endean & Impicciatore, 1967).This principle, called caerulein, has recently been isolated in a pure form and its amino-acid composition and sequence have been fully elucidated (Anastasi, Erspamer & Endean, 1967, 1968).It may be seen from the amino-acid sequence that caerulein shows a close resemblance to gastrins, especially to gastrins II. SO3HPyr-Gln-Asp-Tyr-Thr-Gly-Trp-Met-Asp-Phe-NH2 Caerulein SO3HPyr-Gly-Pro-Trp-(Glu),-Ala-Tyr-Gly-Trp-Met-Asp-Phe-NH.W Human gastrin II (Pyr = pyroglutamyl) The structure proposed for caerulein has been confirmed by synthesis (Bernardi, Bosisio, De Castiglione & Goffredo, 1967).This paper describes the occurrence of caerulein in skins from different batches of Hyla caerulea and from other Australian species of Hyla, the distribution of caerulein in different regions of the skin, the behaviour of the decapeptide during drying of the skin, and the occurrence in the skins of Australian hylids of other active constituents, such as indolealkylamines and imidazolealkylamines. METHODS A mphibian materialThe following Hyla material was used in this study.1. Fifteen adult specimens of Hyla caerulea captured in May, 1964.The total weight of the dried skins was 13.5 g and the average weight of one skin was 0.9 g.
No takes yet. Share an insight, caveat, or question.
de et al. (1968) studied this question.