Renal subcapsular islet cell transplantation in the dog: a preliminary report

During the last two decades, islet cell transplantation has been pursued both experimentally and clinically in an effort to ameliorate diabetes mellitus. At present, however, islet cell transplantation still remains at the experimental stages as far as the treatment of diabetes is concerned. Also, culture of islet cells has proved to be rather frustrating and difficult. No consistent techniques have been developed, and simplified methods for islet cell preparation and adequate sites for islet cell placement would allow for further progress in this area. Ultimately, rejection remains the greatest obstacle to success. We report a simplified technique for enriching dog pancreatic islet cells. This preparation was injected into the renal subcapsular space in both homograft (3 experiments) and heterograft (3 experiments) situations. After six weeks, nephrectomy was performed, and histochemical techniques demonstrated many groups of live islets in between the tubules in the renal cortex. No acinar cells were observed. Blood samples from the renal artery and renal vein at the time of nephrectomy revealed an average 36.9% increase in insulin concentraction on the renal veins, supporting an active secretory role of these transplanted islet cells. This technique points to (i) the possible role of a "renal factor" in promoting growth of islet cells and (ii) the feasibility of successful transplantarion of enriched islet cells as a potential approach to the curative treatment of diabetes mellitus

Toxicity of the hyperglycaemic-inducing extract of the Annatto (Bixa orellana) in the dog

The Annatto seed coat extract, which is commonly used in folklore in treating diabetes mellitus, has been investigated for its effects on blood sugar levels in the dog. An alkali-soluble hyperglycaemia-inducing fraction was detected, and detailed studies revealed toxic effects in the pancreas and liver accompanied by hyperglycaemia and apparent tendency to increased insulin levels. The toxicity was diminished by feeding riboflavin. The relevance of this finding points to a possible aetiological role in the development of amlnutrition-related diabetes mellitus and also to the potential toxicity inherent in the widespread use of folklore medicines