Summary
Substances with Somatostatin-Like Immunoreactivity (SLI) were extracted using 2 N
acetic acid, from the three pancreatic lobes and the intestine of the duck. The concentration
of SLI was found to be very high in the pancreas (4.2 μg/g wet weight), the splenic
lobe containing 80% of pancreatic SLI compared with 10% for the dorsal and 10% for
the ventral lobes.
SLI was equally distributed between duodenum, jejunum and ileum and between their
mucosal and muscular layers. Chromatography of pancreatic extracts, using a Sephadex
G-25 column, showed mainly the tetradecapeptide form (somatostatin-14, S-14) with
a small amount of big somatostatin. Chromatography of intestinal extracts revealed
three peaks with SLI: big somatostatin, somatostatin-28 (S-28) and S-14. The substance
represented by the predominant peak was co-eluted with that of synthetic S-28. In
normal ducks, portal plasma SLI corresponded to big somatostatin S-28 and S-14. After
total pancreatectomy the S-14 form disappeared from portal plasma, whereas, when the
intestinal blood vessels were ligatured, the S-28 form disappeared. We therefore hypothesize
that in portal blood, S-14 has a mainly pancreatic origin, and S-28 a mainly intestinal
origin.
Key-Words:
Somatostatin-Like Immunoreactivity
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Big Somatostatin
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Somatostatin-28
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Somatostatin-14
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Pancreas
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Intestine
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Duck
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Portal Plasma
