Environmental Science & Technology · 2014 · 67 citations · 42 references
MedicineEndocrinologyPharmacologyApoptosisCellular PharmacologyHormone BiochemistryDiabetes MellitusEndocrine ToxicityInsulin ResistanceMammalian EndocrinologyPancreatic DiseasesPancreatic EndocrinologyExocrine OrgansGlucose Homeostasis DisruptionGlucose Homeostasis DisturbanceHistopathological EffectsIslet Cell DysfunctionOrganotin ToxicityPancreatic Islet CellsPancreatic Islet Function
Organotin compounds such as TBT have been linked to diabetes and insulin resistance, yet their histopathological impact on pancreatic islets and exocrine tissue remains unclear, possibly due to differential expression of estrogen and androgen receptors. Male KM mice received oral TBT at 0.5, 5, and 50 µg/kg every three days, and immunohistochemistry revealed ER and AR expression in vascular endothelium, ductal cells, and islets but not in exocrine tissue. After 60 days of TBT exposure, fasting plasma glucose rose while serum insulin and glucagon fell; 45‑day treatment increased dose‑dependent apoptosis in islets and exocrine pancreas, reduced islet proliferation, and altered hormone levels (↓estradiol, ↓T3, ↑testosterone) with decreased ERα and increased AR, leading to reduced islet area and disrupted glucose homeostasis.
It has been reported that organotin compounds such as triphenyltin or tributyltin (TBT) induce diabetes and insulin resistance. However, histopathological effects of organotin compounds on the Islets of Langerhans and exocrine pancreas are still unclear. In the present study, male KM mice were orally administered with TBT (0.5, 5, and 50 μg/kg) once every 3 days. The fasting plasma glucose levels significantly elevated, and the levels of serum insulin or glucagon decreased in the animals treated with TBT for 60 days. In animals treated for 45 days, the number of apoptotic cells in the islets and exocrine pancreas was elevated in a dose-dependent manner. The percentage of proliferating (PCNA-positive) cells was decreased in the islets, while it was increased in exocrine acinar cells. Immunohistochemistry analysis showed that estrogen receptor (ER) and androgen receptor (AR) were present in vascular endothelium, ductal cells, and islet cells, but absent from pancreatic exocrine cells. TBT exposure decreased the production of estradiol and triiodothyronine and elevated the concentration of testosterone, and resulted in a decrease of ERα expression and an elevation of AR in the pancreas measured by Western boltting. The results suggested that TBT inhibited the proliferation and induced the apoptosis of islet cells via multipathways, causing a decrease of relative islet area in the animals treated for 60 days, which could result in a disruption of glucose homeostasis. The different presence of ERs and AR between the islets and exocrine pancreas might be one of reasons causing different effects on cell proliferation.
42
β-Cell Deficit and Increased β-Cell Apoptosis in Humans With Type 2 Diabetes
Alexandra E. Butler, Juliette Janson, Susan Bonner‐Weir et al. · Diabetes · 2003 · 4K citations
Medicine, Endocrinology, Physiology +17
Type 2 Diabetes-a Matter of ß-Cell Life and Death?
Christopher J. Rhodes · Science · 2005 · 892 citations