Autotransplantation of the Pancreas in Sheep: Insulin Secretion From the Transplant

Abstract

SUMMARY A method of transplanting a part of the pancreas into an exteriorized carotid artery—jugular vein loop in the neck of the sheep is described. Glucose and butyrate solutions were infused directly into the transplanted pancreas and shown to be powerful direct stimuli of insulin secretion by the pancreatic transplant. Patterns of insulin secretion during prolonged infusions of glucose and butyrate solutions into the pancreatic transplant are described. One of the sheep described here died 5 months after the transplantation. The other three sheep are all surviving in healthy condition 9, 12 and 18 months respectively, after the transplantation. The transplants of these three sheep continue to secrete insulin.

Studies With the Autotransplanted Ovine Pancreas: Glucagon and Insulin Secretion

“…Also, it is unlikely, as discussed by Bell et al (1970), that the isotonic saline in which infusates were made up affected the pancreatic responses in any way. Orosz et al (1974) and Gerich et al (1974a) report inhibitions of both glucagon and insulin secretion by heparin, which was infused as an anticoagulant in the earlier experiments of this series, but present results show that at the levels used heparin did not markedly affect these secretions by either the ovine pancreatic remnant or the transplant.…”

“…The main pancreatic duct was not ligated at a preliminary operation, as was the practice earlier in this work (Bell et al 1970). When ligation is not done, digestive secretion from the transplant forms a fistula in the loop through which it discharges for several weeks after the transplant operation; eventually this secretion ceases and the fistula heals.…”

“…Transplant perfusion experiments were carried out as described in detail by Bell et al (1970). Briefly, infusions were made through a scalp-vein, or similar, needle inserted into the loop carotid artery on the thoracic side of the transplant, the artery being clamped off on the head side so that all of the infusate passed into the transplant.…”

“…Autotransplantation of a large portion of the pancreas of the Merino ewe into a specially prepared site in the neck for physiological studies has been described in full by Holland (1969) and Bell et al (1970). Briefly, it involves the surgical fashioning on the left side of the neck of a bipedicled loop of skin within which the left carotid artery and left jugular vein are incorporated, and subsequently, at a later operation, the transfer of the relatively discrete tail portion of the pancreas, comprising one-third to one-half of the organ, to this loop, where the pancreatic blood vessels are anastomosed, end-to-side, to the carotid artery and the jugular vein respectively.…”

“…This preparation has proved especially convenient for the study of biochemical factors involved in insulin secretion (Bell et al 1970) in that it is far more accessible than the in situ pancreas. Thus, experiments involving perfusions and blood sampling right at gland level can be carried out without anaesthesia or surgical trauma or any other major stress to the animal.…”