Epidermal growth factor (EGF) was detected in the milk of adult lactating Sprague-Dawley female rats (38.85 ng/ml) and in the stomach (37.25 ng/g content) and plasma (32.36 ng/ml) of 13-day-old suckling offspring. Sixty-nanogram (0.12 mCi/ml) doses of 125I-EGF were administered orally to sucklings in 200 microliters of buffer for 0, 0.5, 1.0, and 3.0 h. Lung, liver kidney, brain, and blood each contained 1% or less of the administered radioactivity. Stomach wall (8%) and content (63%), intestinal wall (15%) and flushing (38%), and skin (18%) contained larger amounts reaching maxima in these three regions at 0, 0.5, and 3.0 h, respectively. Except for skin, a substantial amount of radioactivity from all tissues represented intact (6-90%) and immunoreactive (3-90%) EGF based on Sephadex G-25 chromatography and anti-EGF antibody binding, respectively. From 30 to 55% of the radioactivity from wall (gastric or small intestinal) or lumina was also capable of binding to A-431 cell surface receptors. Isoelectric points of major species found in stomach (4.2), intestine (4.1), and other tissues differed from that of administered EGF (4.5).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.