Metal Ions Induce Expression Pancreatic Exocrine and of Met allot hionein in Endocrine Cells

Autor: Andrews, Glen K., Kage, Karen, Palmiter-Thomas, Pamela, Sarras, Michael P.
Zdroj: Pancreas; September 1990, Vol. 5 Issue: 5 p548-554, 7p
Abstrakt: Northern blot hybridization established that metallothionein (MT)mRNA levels were dramatically elevated in the rat pancreas following injection of Cd or Zn salts. To determine which pancreatic cell types express the MT gene, Northern blot hybridization analysis of RNA from preparations enriched for acini, in situ hybridization, and immunocytochemistry were used. RNA from pancreatic acini of Zn-treated rats contained high levels of MT mRNA. In control rats, in situ hybridization suggested very low levels of MT mRNA in both exocrine and endocrine cells in the pancreas, but these levels were dramatically increased in both these cell populations following metal injection. In contrast, levels of insulin-I mRNA in the endocrine cells were not affected by metal injection. A similar result with MT mRNA was obtained in mouse and chicken pancreas using Northern blot and in situ hybridization. Immunocyto chemistry detected MT in the rat acinar cell cytoplasm following metal injection. Although inconsistent with in situ hybridization studies and immunocytochemical analysis of exocrine cells, immunocytochemistry for MT indicated a uniform staining pattern of islet cells that was unaffected by metal treatment. These results establish that metal ion induction of the MT genes in pancreasoccurs in both endocrine and exocrine cells, which suggests that this proteinhas diverse physiologic functions in this organ.
Databáze: Supplemental Index