Localization of endocrine pancreatic islets

Area of Science:

• Biomedical imaging
• Transplantation immunology
• Endocrinology

Background:

• Pancreatic islet transplantation is a key treatment for diabetes mellitus.
• Current diagnostic methods for islet rejection and endocrine function are insufficient.
• Novel imaging agents are needed for monitoring transplanted islets.

Purpose of the Study:

• To evaluate dithizone (DTZ) and a synthetic iodo-derivative (I-DTZ) as markers for identifying pancreatic islets.
• To assess the safety and efficacy of DTZ and I-DTZ in vivo and in vitro.
• To explore their potential clinical applications in islet transplantation and tumor detection.

Main Methods:

• Ex vivo staining of human pancreatic islets with DTZ.
• In vivo localization of rat pancreatic islets using intravenous DTZ or I-DTZ.
• Transplantation of rat islets into diabetic recipients.
• Macroscopic and microscopic identification of transplanted islets post-injection.
• Assessment of islet endocrine function via plasma insulin and glucose levels.

Main Results:

• DTZ and I-DTZ specifically stained pancreatic islets both in vitro and in vivo.
• Intravenous administration did not impair islet endocrine function.
• Successful macroscopic and microscopic identification of viable transplanted islets was achieved.
• Human islets exhibited red staining with DTZ/I-DTZ.

Conclusions:

• DTZ and I-DTZ are effective agents for identifying pancreatic islets.
• These compounds show promise for in vivo and in vitro diagnostic applications.
• Potential clinical uses include monitoring islet allograft rejection and detecting insulinomas.