[Treating STZ-induced diabetic rats with agarose microcapsulated porcine islets]

To study the function of microencapsulated porcine islets in vitro and in vivo.

Consecutive perfusion of collagenase via pancreatic ducts was used to isolate porcine islet of langerhans. The micro encapsulates were made by phase-separation method with Chinese-made agarose as immunoisolation membrane, 21 diabetic rats were used, 6 for comparing and 15 for transplantation. Six received intraperitoneally uncapsulated islets, 6 received intraperitoneally capsulated islets, and 3 injected uncapsulated islets under kidney capsules.

The islets could secrete insulin consecutively for a month, and the cells in capsules survived very well without autolysis. In the early two days' culture, the islets had marked reactions to the stimulation from glucose in high concentration and theophylline. The amount of insulin released was 1.83 times and 2.28 times as much as that of glucose in low concentration respectively (P < 0.01). 2000-3000 microencapsulated islets per rat were transplanted intraperitoneally in six diabetic rats without the use of immunosuppressive drugs. On the 4th day, blood sugar dropped significantly until the 7th day, when it was in normal range. The concentration of blood sugar remained for 30 days.

The agarose microcapsule processes a better function of immunoisolation, which may lay a foundation of treating IDDM with encapsulated porcine islets grafting.