Ontogenic expression of somatostatin-messenger RNA in the intestinal tract of neonatal rats.
Ontogenic expression of somatostatin (SRIF) -messenger RNA (mRNA) in the gastrointestinal tract was examined in neonatal rats aged from 1 day preterm to 60 days postpartum in comparison with that in the hypothalamus. SRIF-mRNA in the hypothalamus was already expressed in prenatal rats and its developmental change was relatively small. In contrast, a unique pattern of SRIF-mRNA expression was seen in the different intestinal regions, gastric antrum, duodenum, jejunum and colon. In the duodenum, SRIF-mRNA level was low at birth, markedly increased during the postnatal 3 days and declined to the previous level by day 21. Jejunal SRIF-mRNA was found in neonates but progressively decreased in a similar way to duodenum. On the contrary, gastric SRIF-mRNA level, which was low during early development, rose rapidly to a peak on day 21 and gradually declined to an adult level. In the colon age-related change was not conspicuous, remaining at a low level. These results indicate that (1) expression of SRIF gene in the intestinal tract is regulated by local factor(s) as well as developmental stage, and (2) shift of SRIF-mRNA pattern occurs during weaning from the duodenum-dominant infantile pattern to the gastric-dominant adult pattern.
Department of Pediatrics, Kitasato University, School of Medicine, Sagamihara, Japan.
X Y
XY
Yin
T
T
Koshimizu
Y
Y
Yokota
K
K
Shibayama
Y
Y
Ohyama
K
K
Yashiro
D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn; D004068:Digestive System Physiological Phenomena; D015870:Gene Expression / Q000502:physiology; D009857:Oncogenes / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics*; D051381:Rats; D011919:Rats, Inbred Strains; D013004:Somatostatin / Q000235:genetics*
D012333:RNA, Messenger; D013004:Somatostatin