TY - JOUR
T1 - Molecular and cellular responses of islets during pertubations of glucose homeostasis determined by in situ hybridization histochemistry
AU - Chen, L.
AU - Komiya, I.
AU - Inman, L.
AU - McCorkle, K.
AU - Alam, T.
AU - Unger, Roger H
PY - 1989
Y1 - 1989
N2 - We have evaluated in situ hybridization histochemistry as a means of estimating simultaneously the level of prohormone mRNA and the dimensions of rat pancreatic islets. Localization of the 27-mer 32P-labeled oligonucleotide probes for rat proinsulin I, glucagon, and prosomatostatin I corresponded with localization of antibodies to the three hormones. In normal rats subjected to chronic hyperglycemic clamping, the density of the proinsulin mRNA signal increased 54%, islet size and number increased ~100%, while proglucagon mRNA signal was reduced 81%. Resection of 50% of the pancreas increased proinsulin mRNA 36% and proglucagon mRNA 500%; islet area doubled and islet number increased 50%. In 150-day-old diabetic ob/ob mice, there was an 18-fold expansion in islet area, a 4-fold increase in islet number, but no increase in insulin gene expression. In insulin-dependent streptozotocin-treated diabetic rats, islet area and number were profoundly reduced; insulin deprivation failed to raise proinsulin mRNA in surviving beta cells above control levels. Proglucagon mRNA was high despite the hyperglycemia but was reduced by insulin within 1 hr, suggesting that insulin regulates glucagon gene expression or is required for its regulation by glucose. In situ hybridization of rat islets provides a valid semiquantitative index of insulin and glucagon biosynthesis and of islet dimensions and reveals that normal but not diabetic islets meet increased insulin demand by increasing both number and biosynthetic activity of beta cells.
AB - We have evaluated in situ hybridization histochemistry as a means of estimating simultaneously the level of prohormone mRNA and the dimensions of rat pancreatic islets. Localization of the 27-mer 32P-labeled oligonucleotide probes for rat proinsulin I, glucagon, and prosomatostatin I corresponded with localization of antibodies to the three hormones. In normal rats subjected to chronic hyperglycemic clamping, the density of the proinsulin mRNA signal increased 54%, islet size and number increased ~100%, while proglucagon mRNA signal was reduced 81%. Resection of 50% of the pancreas increased proinsulin mRNA 36% and proglucagon mRNA 500%; islet area doubled and islet number increased 50%. In 150-day-old diabetic ob/ob mice, there was an 18-fold expansion in islet area, a 4-fold increase in islet number, but no increase in insulin gene expression. In insulin-dependent streptozotocin-treated diabetic rats, islet area and number were profoundly reduced; insulin deprivation failed to raise proinsulin mRNA in surviving beta cells above control levels. Proglucagon mRNA was high despite the hyperglycemia but was reduced by insulin within 1 hr, suggesting that insulin regulates glucagon gene expression or is required for its regulation by glucose. In situ hybridization of rat islets provides a valid semiquantitative index of insulin and glucagon biosynthesis and of islet dimensions and reveals that normal but not diabetic islets meet increased insulin demand by increasing both number and biosynthetic activity of beta cells.
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U2 - 10.1073/pnas.86.4.1367
DO - 10.1073/pnas.86.4.1367
M3 - Article
C2 - 2645581
AN - SCOPUS:0024594508
SN - 0027-8424
VL - 86
SP - 1367
EP - 1371
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 4
ER -