Role of vasoactive intestinal polypeptide (VIP) and endogenous somatostatin on the secretion of epidermal growth factor (EGF): studies on duodenal tissue cultures.
Epidermal Growth Factor (EGF)-containing cells have been found in Brunner's glands in the same area where several regulatory peptides are released. The present study was aimed at testing the release and the regulation of EGF secretion from cultured duodenal biopsies obtained from healthy individuals by gastroscopy. The effects and the interaction of VIP and somatostatin on the hormone release were studied. Duodenal biopsies were cultured at 37 degrees C in Mc Coy's buffer, gassed with 95% O2 and 5% CO2. After 30 min, the culture medium was decanted for the measurement of the hormones by RIA. To measure the protein content, the tissue was then homogenized; EGF detected in the culture was 11.5 ng/mg protein. The addition of VIP in the medium increased EGF mean levels to 21.6 ng/mg protein (P less than 0.01). The biopsies thus obtained were cultured with anti-somatostatin antibodies to evaluate the influence of endogenous somatostatin on EGF secretion. The inclusion of anti-somatostatin antibodies increased the EGF levels to 41.2 ng/mg protein (P less than 0.01). The combined addition of anti-somatostatin antibodies and VIP in the culture caused a mean EGF increase significantly higher than the values obtained separately by VIP and somatostatin (P less than 0.01). In conclusion, we can suggest a triangular interaction model of EGF release, where the somatostatin seems to be the negative monitor of over-secreted VIP and EGF from the gut.
Zandomeneghi
R
R
Istituto di Clinica Medica, Università di Modena, Italy.
Montanari
P
P
Serra
L
L
Pavesi
C
C
Poppi
C
C
Baumgartl
U
U
Bottura
L
L
D000328:Adult; D000906:Antibodies / Q000276:immunology; D002011:Brunner Glands / Q000187:drug effects / Q000378:metabolism*; D046508:Culture Techniques; D004815:Epidermal Growth Factor / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D013004:Somatostatin / Q000502:physiology*; D014660:Vasoactive Intestinal Peptide / Q000502:physiology*
D000906:Antibodies; D014660:Vasoactive Intestinal Peptide; D013004:Somatostatin; D004815:Epidermal Growth Factor