Abstracts
1999 Digestive Disease Week

# 3483 GROWTH HORMONE ACUTELY STIMULATES INTESTINAL SODIUM-GLUCOSE CO-TRANSPORTER ACTIVITY
A Tavakkolizadeh, R Shen, Brigham and Women's Hosp, Boston, MA; J Jasleen, Brigham and Women's Hosp, Harvard Med Sch, Boston, MA; D Soybel, D Jacobs, Brigham and Women's Hosp, Boston, MA; M Zinner, S Ashley, Brigham and Women's Hosp, Harvard Med Sch, Boston, MA; Edward Whang, Brigham and Women's Hosp, Boston, MA

The efficacy of growth hormone (GH) as part of the treatment regime to augment the adaptive response in patients with short bowel symdrome is controversial. Previous studies have reported that GH acutely increases water and electrolyte absorption but the effect of this hormone on glucose uptake is unknown. We have used an in vitro model to study the acute effect of GH on the sodium-dependent glucose absorption. Methods: Mucosal preparations of proximal rat jejunum were mounted in the Ussing chamber. Tissues were bathed in a physiological solution with 10 mM glucose in the serosal and equimolar concentration of mannitol in the mucosal chambers. Following an equilibration period, GH (2X10-6M) or vehicle (control) was added to the serosal chamber. Forty minutes later, 3-O-Methylglucose (3-O-mG, 30 mM) was added to both chambers and the change in short-circuit current (DIxc) recorded. In separate experiments, the tissues were pre-treated with phyloidzin (1 mM, both chambers) for 15 minutes prior to the addition of 3-O-mG. Results: GH did not produce a significant change in Isc or conductance compared to controls. Tissues treated with GH had a significantly greater increase in Isc (DIsc) induced by 3-O-mG versus controls (* p<0.05 by t-test) (Fig. 1). The effect of GH was abolished by phloridzin, a specific blocker for the Na+/Glucose co-transporter. 3-O-mG resulted in no significant change in tissue conductance. Conclusions: These results suggest, for the first time, that GH acutely stimulates jejunal Na+-dependent glucose absorption. The results provide another rational for the use of GH as part of a treatment regiment in patients with the short bowl syndrome and other intestinal absorptive disorders.

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