The effects of somatostatin on cholera toxin-induced secretory diarrhea and the appearance of glycoenzymes in the intestinal lumen and intestinal lymph were investigated in rat small intestine. After exposure to cholera toxin, marked fluid accumulation in the small intestinal tract and elevation of the jejunal mucosal cyclic AMP (cAMP) concentration were observed. The activity of alkaline phosphatase, aminopeptidase and sucrase increased in the intestinal lumen after toxin exposure. In intestinal lymph, alkaline phosphatase activity was increased after cholera toxin administration, while aminopeptidase activity remained unchanged. Somatostatin suppressed cholera toxin-induced secretory diarrhea, but it did not affect the elevated mucosal cAMP concentration. This peptide also inhibited the appearance of glycoenzymes in the intestinal lumen and lymph induced by cholera toxin administration. These results suggest that somatostatin exerts its inhibitory effects on cholera toxin-induced secretory diarrhea and on the appearance of glycoenzymes in the intestinal lumen and lymph by affecting processes beyond cAMP formation.

No abstract

Incubating the dried cells of Brevibacterium sojae No.425-40 in alkaline buffer, the ex-Then the determination of the optimum condition of the excretion and the investigation on the enzyme responsible for the degradation of endogenous RNA were carried out. In the experiments using sonicate and disrupted cells, it appeared that orthophosphate and Mg++ might be accelerative or essential for the degradation of endogenous RNA phates were not detected. Although it was not clear whether phosphodiesterase concerned with the degradation of intracellular RNA or not, it was suggested that polynucleotide phosphorylase acted mainly on the degradation. to 2% of dried cells in 0.05M carbonate-bicarbonate buffer (pH 10) and incubating it at