tacrolimus and Hypoglycemia

The aim of this study was to describe the National Institutes of Health's experience initiating an islet isolation and transplantation center, including descriptions of our first six recipients, and lessons learned.. Six females with chronic type 1 diabetes, hypoglycemia unawareness, and no endogenous insulin secretion (undetectable serum C-peptide) were transplanted with allogenic islets procured from brain dead donors. To prevent islet rejection, patients received daclizumab, sirolimus, and tacrolimus.. All patients noted less frequent and less severe hypoglycemia, and one-half were insulin independent at 1 year. Serum C-peptide persists in all but one patient (follow-up 17-22 months), indicating continued islet function. Two major procedure-related complications occurred: partial portal vein thrombosis and intra-abdominal hemorrhage. While we observed no cytomegalovirus infection or malignancy, recipients frequently developed transient mouth ulcers, diarrhea, edema, hypercholesterolemia, weight loss, myelosuppression, and other symptoms. Three patients discontinued immunosuppressive therapy: two because of intolerable toxicity (deteriorating kidney function and sirolimus-induced pneumonitis) while having evidence for continued islet function (one was insulin independent) and one because of gradually disappearing islet function.. We established an islet isolation and transplantation program and achieved a 50% insulin-independence rate after at most two islet infusions. Our experience demonstrates that centers not previously engaged in islet transplantation can initiate a program, and our data and literature analysis support not only the promise of islet transplantation but also its remaining hurdles, which include the limited islet supply, procedure-associated complications, imperfect immunosuppressive regimens, suboptimal glycemia control, and loss of function over time.

Topics: Adult; Antibodies, Monoclonal; Antibodies, Monoclonal, Humanized; Blood Glucose; Daclizumab; Diabetes Mellitus, Type 1; Drug Therapy, Combination; Female; Follow-Up Studies; Humans; Hypoglycemia; Immunoglobulin G; Immunosuppression Therapy; Immunosuppressive Agents; Islets of Langerhans Transplantation; Middle Aged; Postoperative Complications; Reproducibility of Results; Sirolimus; Tacrolimus; Time Factors

Topics: Area Under Curve; Blood Glucose; C-Peptide; Cyclosporine; Diabetes Mellitus, Type 1; Female; Humans; Hyperglycemia; Hypoglycemia; Immune Tolerance; Immunosuppressive Agents; Islets of Langerhans; Islets of Langerhans Transplantation; Middle Aged; Tacrolimus

Tacrolimus is an immunosuppressive drug that causes glucose intolerance. On the other hand, ciprofloxacin, which is widely used in the treatment of infectious diseases, is known to cause hypoglycemia as a side effect. We investigated the effects of tacrolimus and ciprofloxacin on serum glucose and insulin levels in rats, as well as on insulin secretion and the viability of HIT-T15 cells. The rats received intraperitoneal injections of tacrolimus and/or ciprofloxacin for 1 week, and their arterial blood was sampled after the administration of glucose. HIT-T15 cells were cultured in the presence of tacrolimus and/or ciprofloxacin, and the insulin level in the supernatant was measured. Ciprofloxacin did not show a significant effect on serum glucose and insulin levels after multiple administrations in the rats. In contrast, rats in the tacrolimus treatment group showed low serum insulin and high serum glucose levels. Moreover, the coadministration of ciprofloxacin and tacrolimus resulted in higher glucose levels compared with tacrolimus alone 0.5 h after glucose stimulation. In addition, we observed that the rats administered tacrolimus and/or ciprofloxacin had low body weight and food intake. Tacrolimus caused a dose-dependent decrease in the viability of the HIT-T15 cells. Furthermore, both drugs were highly toxic to HIT-T15 cells. In contrast, tacrolimus alone and coadministration of the drugs resulted in no significant difference in insulin secretion. These results suggest that the cytotoxic effects of ciprofloxacin and tacrolimus cause a decrease in insulin secretion, leading to glucose intolerance.

Topics: Animals; Anti-Infective Agents; Body Weight; Cell Survival; Cells, Cultured; Ciprofloxacin; Cricetinae; Dose-Response Relationship, Drug; Eating; Glucose; Glucose Intolerance; Hypoglycemia; Immunosuppressive Agents; Insulin; Insulin-Secreting Cells; Male; Rats; Rats, Wistar; Tacrolimus

To determine whether pancreatic islet transplantation can control diabetes and prevent severe life-threatening hypoglycaemia.. A single-arm observation study of six patients undergoing islet transplantation. All patients had had type 1 diabetes mellitus for over 5 years and documented episodes of repeated severe hypoglycaemia. Islets were isolated from donor pancreases digested by Liberase. Separated islets were infused into the recipient's liver via the portal vein. Patients were immunosuppressed with daclizumab, sirolimus and tacrolimus. The transplants were performed at Westmead Hospital, NSW, between October 2002 and February 2005.. Normal blood glucose control without administration of exogenous insulin; demonstration of islet function and abolition of hypoglycaemia.. Five of the patients received two islet infusions, and the sixth was withdrawn after one infusion following a portal vein thrombosis. Three patients became insulin-independent, with excellent glycaemic control. Two had islet function with circulating C-peptide, improved glycaemic control, reduced insulin requirement and abolition of severe hypoglycaemia. However, over a 2-year period, graft function deteriorated. Recipients who were initially insulin free remained C-peptide positive but required supplemental insulin. Complications included one postoperative bleed, two portal vein thromboses (which resolved completely), presumed recurrence of tuberculosis in one patient, and deterioration in renal function in one patient.. Islet transplantation is effective at improving glycaemic control and hypoglycaemia unawareness in the short to medium term. However, problems with long-term safety of immunosuppression, islet-induced thrombosis and early detection of loss of islet function remain to be addressed.

Topics: Adult; Age Factors; Antibodies, Monoclonal; Antibodies, Monoclonal, Humanized; Australia; Blood Glucose; Daclizumab; Diabetes Mellitus, Type 1; Follow-Up Studies; Graft Survival; Humans; Hypoglycemia; Immunoglobulin G; Immunosuppressive Agents; Islets of Langerhans Transplantation; Middle Aged; Postoperative Complications; Sirolimus; Tacrolimus; Time Factors; Treatment Outcome

Blockade of mitochondrial permeability transition protects against hypoglycemic brain damage. To study the mechanisms downstream from mitochondria that may cause neuronal death, we investigated the effects of cyclosporin A on subcellular localization of apoptosis-inducing factor and cytochrome c, activation of the cysteine proteases calpain and caspase-3, as well as its effect on brain extracellular calcium concentrations. Redistribution of cytochrome c occurred at 30 min of iso-electricity, whereas translocation of apoptosis-inducing factor to nuclei occurred at 30 min of recovery following 30 min of iso-electricity. Active caspase-3 and calpain-induced fodrin breakdown products were barely detectable in the dentate gyrus and CA1 region of the hippocampus of rat brain exposed to 30 or 60 min of insulin-induced hypoglycemia. However, 30 min or 3 h after recovery of blood glucose levels, fodrin breakdown products and active caspase-3 markedly increased, concomitant with a twofold increase in caspase-3-like enzymatic activity. When rats were treated with neuroprotective doses of cyclosporin A, but not with FK 506, the redistribution of apoptosis-inducing factor and cytochrome c was reduced and fodrin breakdown products and active caspase-3 immuno-reactivity was diminished whereas the extracellular calcium concentration was unaffected. We conclude that hypoglycemia leads to mitochondrial permeability transition which, upon recovery of energy metabolism, mediates the activation of caspase-3 and calpains, promoting cell death.

Topics: Animals; Apoptosis Inducing Factor; Calcium; Calpain; Caspase 3; Caspases; Cell Count; Cyclosporine; Cytochrome c Group; Dentate Gyrus; Enzyme Activation; Flavoproteins; Hypoglycemia; Intracellular Fluid; Male; Membrane Proteins; Microelectrodes; Neurons; Protein Transport; Rats; Rats, Wistar; Tacrolimus

In the present study the time-course of DNA fragmentation following insulin-induced hypoglycemia was examined. In situ localization of DNA breaks were studied by the terminal deoxynucleotidyl transferase-mediated biotin-deoxyuridine triphosphate nick-end labelling method, and the temporal profile of DNA-fragmentation by agarose gel electrophoresis. Cell nuclei displayed terminal deoxynucleotidyl transferase-deoxyuridine triphosphate nick-end labelling within 3 h of recovery following 30 min of a hypoglycemic insult, and DNA from the hippocampus displayed oligonucleosomal fragmentation. Ultrastructural examination of the dentate granule cells showed mitochondrial swelling during the acute phase of the hypoglycemic insult, which preceded the DNA fragmentation seen in the recovery phase. Cyclosporin A but not tacrolimus, prevented mitochondrial swelling and subsequent DNA fragmentation. We conclude that during severe energy deprivation following hypoglycemia, mitochondrial swelling occurs due to mitochondrial permeability transition and that factors are released, which upon recovery can activate processes leading to DNA fragmentation and cell death.

Topics: Animals; Coma; Cyclosporine; DNA Fragmentation; Electrophoresis, Agar Gel; Hippocampus; Hypoglycemia; In Situ Nick-End Labeling; Male; Mitochondria; Permeability; Rats; Rats, Wistar; Tacrolimus

Induction of the mitochondrial permeability transition (MPT) has been implicated in cellular apoptosis and in ischemia-reperfusion injury. During MPT, a channel in the inner mitochondrial membrane, the mitochondrial megachannel, opens and causes isolated mitochondria to swell. MPT and mitochondrial swelling is inhibited by cyclosporin A (CsA), which may also inhibit apoptosis in some cells. Treatment with CsA (50 mg/kg, i.v.) showed a robust reduction of brain damage when administered 30 min before insulin-induced hypoglycemic isoelectricity of 30 min duration. Ultrastructural examination of the dentate gyrus revealed a marked swelling of dendrites and mitochondria during the hypoglycemic insult. In CsA-treated animals, mitochondria resumed a normal and contracted appearance during and after the hypoglycemic insult. Treatment with FK 506 (2 mg/kg, i.v.), a compound with immunosuppressive action similar to that of CsA, was not protective. Studies on the swelling kinetics of isolated mitochondria from the hippocampus showed that CsA, but not FK 506, inhibits calcium ion-induced MPT. We conclude that CsA treatment during hypoglycemic coma inhibits the MPT and reduces damage and that mitochondria and the MPT are likely to be involved in the development of hypoglycemic brain damage in the rat.

Topics: Animals; Cell Death; Cell Respiration; Cyclosporine; Drug Evaluation, Preclinical; Hippocampus; Hypoglycemia; Immunosuppressive Agents; Male; Mitochondria; Mitochondrial Swelling; Neurons; Permeability; Rats; Rats, Wistar; Tacrolimus