Secretory diarrhea in villous adenoma of rectum: Effect of treatment with somatostatin and indomethacin

Abstract

The effects of treatment with the synthetic longacting somatostatin analogue SMS-201-995 were studied in a patient with a fluid and electrolyte secreting villous adenoma of the rectum. The effects of SMS-201-995 on rectal fluid volume and electrolyte loss, and local and general prostanoid production were compared with those of treatment with indomethacin. During treatment with the somatostatin analogue iso-osmolar rectal fluid production increased about 25%; the quantity of prostaglandin E 2 in the rectal fluid rose almost 20-fold. Prostaglandin F 2α, 6-keto-prostaglandin F 1α and 13,14-dihydro-15-keto-prostaglandin F 2α output showed similar, though less impressive increments during somatostatin treatment. The somatostatin analogue did not affect urinary prostanoid excretion except for levels of 2,3-dinor-thromboxane B 2, which doubled. With indomethacin treatment diurnal rectal fluid production dropped by about 50% and all prostanoids measured in urine and rectal fluid decreased below control values. It appears that the somatostatin analogue SMS-201-995 has a marked stimulatory effect on the in vivo prostanoid production by the villous adenoma. Perhaps this stimulation is not confined to the tumor only, but also affects thromboxane synthesis.