Ontogenic timing mechanism initiates the expression of rat intestinal sucrase activity

Journal Article · Sat Mar 01 00:00:00 EST 1986 · Gastroenterology; (United States)

OSTI ID:5860675

Yeh, K Y; Holt, P R

Morphologic and enzymic differentiation occurs in rat small intestinal epithelium during 16-20 days of postnatal life. This change is considered to be initiated by an ontogenic timing mechanism and is modulated by extrinsic systemic and luminal factors. The importance of the ontogenic timing was tested directly using a transplantation technique in which jejunal isografts from newborn (day 0) and 5-day-old (day 5) rats were implanted under the skin of newborn (day 0) hosts. Isografts showing cryptvillus architecture were obtained in 44% and 21% of transplants, respectively. Day 0 isografts and host intestine expressed sucrase activity at about 16-18 days of age and showed similar crypt cell labeling and epithelial migration after (3H)thymidine injection. Day 5 isografts expressed sucrase activity when the hosts were 13 days of age, whereas host intestine showed no detectable sucrase activity. Isograft lactase activities in both experimental transplant models were significantly higher than host intestinal lactase up to 28 days of age, suggesting that luminal factors are important in modulating lactase activity during the first 4 wk of postnatal life. It is concluded that (a) no systemic factors at day 13 inhibit the expression of sucrase activity and (b) an ontogenic timing mechanism in the jejunum initiates the expression of sucrase activity.

• Research Organization: St. Luke's-Roosevelt Hospital, New York, NY
• OSTI ID: 5860675
• Journal Information: Gastroenterology; (United States), Vol. 3
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
SMALL INTESTINE
ONTOGENESIS
AUTORADIOGRAPHY
ENZYME ACTIVITY
NEONATES
RATS
THYMIDINE
TRITIUM COMPOUNDS
ANIMALS
AZINES
BODY
DIGESTIVE SYSTEM
GASTROINTESTINAL TRACT
HETEROCYCLIC COMPOUNDS
INTESTINES
LABELLED COMPOUNDS
MAMMALS
NUCLEOSIDES
NUCLEOTIDES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANS
PYRIMIDINES
RIBOSIDES
RODENTS
VERTEBRATES
550801* - Morphology- Tracer Techniques