Origin, occurrence, and function of microchimeric cells: V. Quantitative aspects of microchimerism following pancreaticoduodenal transplantation model in rats

Effects of simultaneous kidney-pancreaticoduodenal transplantation on diabetes-induced renal insufficiency in rats

An investigation of the functional and histological changes was done after en-bloc kidney-pancreaticoduodenal transplantation (kpdt) in the diabetes-induced, renal insufficient Lewis rats. For donor preparation, an end-to-side portocaval shunt was performed, and the aortic, vena caval segments, and ureter-bladder patch were obtained. They were anastomosed microsurgically to recipient's aorta, vena cava, and bladder in end-to-side fashion. Of 15 diabetes-induced kpdt rats, 14 survived. Two of the 14 surviving rats showed ischemic necrosis. The remaining 12 transplants showed well-preserved glomeruli and Langerhans islets for 5 months postoperatively. Biochemical data comparing diabetic and sham-operated rats (six rats each), six diabetic controls, and 12 kpdt rats showed no significant statistical difference at said observation period. The diabetes-induced kpdt rats showed improvement of following biochemical data: within 1 week postoperatively, the glucose level fell from 300 to 115 mg/dL; BUN level from >20 to <20 mg/dL; the creatinine level from 1.5 to <1.2 mg/dL. The insulin level returned to normal, 1.1 ng/mL, in 2 weeks. The results demonstrate that the kpdt model is an effective and successful operative technique in diabetic rats and may provide effective therapeutic methods for diabetes-induced renal insufficiency.

Kinetic analysis of microchimerism induced by intrathymic injection of allogeneic splenocytes in mice

Allograft survival facilitated by intrathymic (i.t.) injection of allogeneic cells have shown that modifications of T-cell development induce specific tolerance. One hypothesis is that the resulting microchimerism may play a role in preparing the host immune system for the allograft. To investigate whether the deliberate introduction of allogeneic splenocytes into the thymus of adult mice allows the establishment of a lasting donor/recipient microchimerism, a full allogeneic mouse system (H-2 and Mls) with additional sex mismatch was used. Male cells injected into female mice were detected using an optimized nested-polymerase chain reaction which specifically amplifies the SRY gene with a sensitivity of 1/10(4). After i.t. injection, donor cells were observed early both in the lymph nodes and spleen (75 and 25% of mice, respectively). They were still present on day 6, although preferentially in the thymus (100% of mice) than in the lymph nodes (50% of mice) or in the spleen (22% of mice). After intraperitoneal (i.p.) or subcutaneous (s.c.) injection, donor cells were early (2 h) but transiently detected in the thymus, since on day 6 they were detected in 0 and 17% of mice after i.p. and s.c. injection, respectively. Kinetics of donor-cell detection was similar both in the spleen and lymph nodes with a clear decrease in the percentage of mice with donor-cell detection between day 2 and day 6 (20 and 17% of positive mice for the spleen after i.p. and s.c. injections, respectively--20 and 33% of positive mice for the lymph nodes after i.p. and s.c. injections, respectively). Our results clearly show that i.t. injection of allogeneic splenocytes induces a microchimerism which is both more lasting and detected in a higher percentage of mice than by the i.p. and s.c. routes, both at the central (thymus) and peripheral (spleen) levels.