Format

Send to:

Choose Destination
See comment in PubMed Commons below
Gastroenterology. 1991 Aug;101(2):410-5.

Circadian rhythm of cellular proliferation in the human rectal mucosa.

Author information

  • 1Department of Internal Medicine, University of Utah School of Medicine, Salt Lake City.

Abstract

Circadian rhythms of DNA synthesis and cellular proliferation in the gastrointestinal mucosa have been well documented in animal models. This investigation was designed to determine whether similar rhythms could be demonstrated in the human rectal epithelium: 24 studies were performed in 16 healthy men under fasting (n = 14) and fed (n = 10) conditions. Rectal mucosal biopsy specimens were obtained through a proctoscope every 2 or 3 hours for a 24-hour span. Ex vivo measurements of tritiated thymidine incorporation into DNA were made on the mucosal samples. Feeding and time of day were each found to have an effect on the rate of thymidine incorporation into the DNA of rectal mucosal cells. Both fasted and fed subjects showed significant circadian rhythms in thymidine incorporation, which peaked at about 7 AM. Fasting lowered the overall mean thymidine uptake without altering the rhythm. Thymidine uptake generally reflects the amount of DNA synthesis in the sampled tissue. Therefore, these data may be important in the design of cancer chemotherapeutic regimens that use drugs specifically active during DNA synthesis.

PMID:
2065918
[PubMed - indexed for MEDLINE]
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Elsevier Science
    Loading ...
    Write to the Help Desk