EVIDENCE ON SECRETION OF EPIDERMAL GROWTH-FACTOR BY THE ESOPHAGEAL MUCOSA IN HUMANS

Luminal release of esophageal epidermal growth factor (EGF) into the p erfusing solutions (saline, HCl, and HCI/pepsin), aspirated with the n ewly developed esophageal perfusion catheter, was measured in 20 healt hy volunteers (12 male, 8 female; mean age 40 yr; range 30-56 yr). A p otential salivary contamination was excluded by a complete seal (with two balloons) of perfused esophageal segment and by a simultaneous, ca refully monitored, collection of saliva. The concentration of EGF in e ach of 16 fully recovered 2-min perfusion samples was measured by RIA kit (Amersham, IL). The concentration of EGF in recovered NaCl perfusa te varied between (mean +/- SEM) 1.78 +/- 0.19 and 2.14 +/- 0.14 ng/ml , whereas output varied between 9.25 +/- 0.98 and 11.14 +/- 0.82 ng/mi n. During perfusion with HCl, both the concentration of EGF within the esophageal perfusate and its secretion declined significantly to a va lue of 0.68 +/- 0.17 ng/ml (p < 0.0001) and 3.56 +/- 0.90 ng/min (p < 0.0001), respectively. Introduction of pepsin into an acidic perfusion solution (0.5 mg/ml of HCI) resulted in a significant increase in EGF concentration (1.99 +/- 0.36 ng/ml; p < 0.001) and output (10.24 +/- 1.84; p < 0.01), compared with EGF values recorded during perfusion wi th HCI. EGF output, calculated from a sealed 7.5-cm segment of the eso phagus, was 10.39 +/- 0.89 ng/min, and was maintained at a steady stat e throughout an entire saline perfusion procedure. We present evidence that human esophageal mucosa has an enormous EGF secretory potential. The rapid esophageal EGF secretory response to intraluminal challenge with aggressive factors implies its role in the maintenance of the mu cosal integrity.