Actions of Ion-transport Peptide from Locust Corpus Cardiacum on Several Htndgut Transport Processes
نویسنده
چکیده
1. Schistocerca gregaria ion-transport peptide (Scg-ITP), a neuropeptide isolated from locust corpora cardiaca, stimulates ileal Cl~ transport (/«:) in a dose-dependent manner and causes increases in Na, K (/K) and fluid reabsorption (7V) as previously observed with crude extracts of corpus cardiacum and with cyclic AMP. Unlike cyclic AMP, ScgITP does not stimulate ileal NH4 secretion. 2. H secretion (7H) in the ileum, which is not affected by cyclic AMP, is almost completely abolished by Scg-ITP. Although ITP may act via cyclic AMP as second messenger to stimulate NaCl, KC1 and fluid reabsorption, it apparently acts through a different intracellular pathway to influence JH. 3. Scg-ITP is unlikely to be the chloride transport stimulating hormone previously reported to act on the rectum, because it did not produce a maximum rectal /sc response and had no effect on either rectal Jv (which is Cl~-dependent) or IK-
منابع مشابه
Locust ion transport peptide (ITP): primary structure, cDNA and expression in a baculovirus system.
Ion transport peptide (ITP) purified from locust nervous corpus cardiacum (CC) has previously been shown to stimulate salt and water reabsorption and inhibit acid secretion in the ileum of Schistocerca gregaria. We used the partial amino acid sequence of purified ITP to derive degenerate primers. These were used to amplify a cDNA from brain RNA using reverse transcription and the polymerase cha...
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