D-[3H]mannoheptulose distribution in streptozotocin-induced diabetic rats transplanted with islets in an implantation module

D-[ 3 H]mannoheptulose was injected intraperitoneally in streptozotocin-induced diabetic rats, that had been transplanted with islets placed in an implantation module. One day after the administration of the tritiated heptose, its volume of distribution, as judged from the plasma radioactive content, averaged 10.0± 2.2ml/g body weight. The radioactive content (dpm/mg wet weight) of the liver (64.5 ± 6.4), kidney (51.0 ± 0.9), muscle (28.9 ± 7.8) and pancreas (28.7±2.6), when compared to that calculated for the transplanted islets (332.7 ± 30.7) yielded a paired islet/pancreas ratio of 11.59 ±0.03. These findings support the recent proposal that radioactive D-mannoheptulose could be used to label preferentially the endocrine moiety of the pancreatic gland.