Pentose cycle pathway in normal and tumoral islet cells.

Relative to protein content, the activity of glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase and the rate of glucose metabolism by the pentose cycle pathway in tumoral insulin-producing cells were similar to or higher than those found in normal rat islets. Hence, the decreased secretory response of tumoral cells to glucose is apparently not attributable to any major anomaly in glucose handling by the hexose monophosphate pathway.