Circadian stage-dependent effects of epidermal growth factor on deoxyribonucleic acid synthesis in ten different organs of the adult male mouse.
Yeh-YC; Scheving-LA; Tsai-TH; Scheving-LE
Endocrinology 1981 Aug; 109(2):644-651
The growth response of various tissues to epidermal growth factor (EGF) was investigated using 6 week old male CD2F1-mice. The EGF was isolated from the submandibular gland of adult male mice. Experimental mice were injected three times (8.33 micrograms EGF/injection; total of 25 micrograms EGF per mouse) intraperitoneally with 0.1 milliliter EGF solution or the vehicle alone. The injections were given over a period of 90 minutes. Other groups of mice, standardized to 12 hours of light alternating with 12 hours of darkness were similarly injected at 1800, 2100, control mice were killed at 4, 8 and 12 hours after the initial injection. Animals received intraperitoneal injections of 24 microcuries of tritium labeled thymidine 30 minutes before sacrifice. The different tissues examined, demonstrated considerable variation in their response at 4, 8, and 12 hours post injection. Increased DNA synthesis was noted in the cornea, tongue, and esophagus at 4, 8, and 12 hours, in the glandular and nonglandular stomach, colon, and rectum at 8 and 12 hours, in the lung at 8 hours and in the liver at 12 hours. There were times when the stimulatory effect of EGF appeared maximally potentiated. Injection of EGF was able to inhibit DNA synthesis at certain times in several tissues such as the small intestine, thymus, bone marrow and spleen. The authors stress that it is important to consider the basic oscillatory behavior of DNA synthesis and mitosis when evaluating any growth promoting or inhibiting agent. The findings suggest that EGF is important in the positive growth control of many tissues, particularly the cornea and the digestive tract.
NIOSH-Publication; NIOSH-Grant; Neurotoxic-effects; Laboratory-animals; Nucleic-acids; Cell-growth; Growth-inhibitors; Deoxyribonucleic-acids; Growth-factors
Anatomy University of Arkansas 4301 West Markham Little Rock, Ark 72201
Neurotoxic Disorders; Neurotoxic-effects
University of Arkansas Med Scis Ltl Rock, Little Rock, Arkansas