Epidermal growth factor: a potential paracrine and autocrine system within the pituitary.
Epidermal growth factor (EGF) secretion and EGF receptor (EGFR) expression were studied by a combination of reverse hemolytic plaque assay (RHPA), which identifies the EGF secreting cells, and immunocytochemical detection of EGFR. Our results showed that 19% of total rat anterior pituitary (AP) cells secrete EGF and 48% of total AP cells possess EGFR. In addition, most of the EGF-secreting cells (73%) possess EGFR. By measuring the size of plaques surrounding EGF-secreting cells, we found that EGF secretion per cell is significantly higher in cells that did not express EGFR (1930 +/- 92 microns2) than in EGFR-expressing cells (1551 +/- 89 microns2). Taken together, these results strongly suggest that EGF acts by both an autocrine and paracrine fashion in the rat anterior pituitary gland.
D000818:Animals; D004815:Epidermal Growth Factor / Q000378:metabolism*; D066246:ErbB Receptors / Q000378:metabolism*; D006462:Hemolytic Plaque Technique; D007150:Immunohistochemistry; D008297:Male; D010903:Pituitary Gland, Anterior / Q000166:cytology / Q000378:metabolism*; D011388:Prolactin / Q000097:blood; D051381:Rats
D004815:Epidermal Growth Factor; D011388:Prolactin; D066246:ErbB Receptors