Development of gastric somatostatin-like immunoreactivity in response to corticosterone acetate and dietary changes in young rats.
The effects of dietary changes from breast milk to solid food and corticosterone acetate administration on somatostatin-like immunoreactivity (SLI) in the gastric antrum and corpus were studied in young and adult rats. At 7 days of age, a single dose of corticosterone acetate (250 mg/kg of body weight) was injected in one group of rats, and a single dose of physiological saline was injected in another group. Each group was divided into two subgroups; one was fed only rat breast milk until 25 days of age and the other weaned (solid food alone) at 21 days of age. Gastric antrums and corpora were removed at various ages for assay of SLI concentrations by radioimmunoassay. In non-corticosterone treated rats, antral and corpus SLI increased gradually until 20 days of age, and after changing from breast milk to solid food on day 21 antral SLI increased 2-fold to the adult level, whereas corpus SLI remained constant. In corticosterone-treated rats, antral and corpus SLI on day 11 was 5-fold that on day 7, and thereafter remained constant before changing from breast milk to solid food; after weaning (solid food alone) antral SLI increased again to reach the adult level at 25 days of age whereas corpus SLI remained constant after weaning. Prolonged breast milk feeding alone did not influence antral or corpus SLI levels in either corticosterone-treated or nontreated rats as compared to levels on day 20.(ABSTRACT TRUNCATED AT 250 WORDS)
D000818:Animals; D002850:Chromatography, Gel; D003345:Corticosterone / Q000031:analogs & derivatives* / Q000494:pharmacology; D005260:Female; D005753:Gastric Mucosa / Q000378:metabolism*; D008297:Male; D010455:Peptides / Q000378:metabolism*; D011863:Radioimmunoassay; D051381:Rats; D011919:Rats, Inbred Strains; D014886:Weaning
D010455:Peptides; C029993:somatostatin-like peptides; C029939:corticosterone acetate; D003345:Corticosterone