Glucose metabolism is altered after loss of L cells and α-cells but not influenced by loss of K cells

TY - JOUR

T1 - Glucose metabolism is altered after loss of L cells and α-cells but not influenced by loss of K cells

AU - Pedersen, J

AU - Ugleholdt, R K

AU - Jørgensen, S M

AU - Windeløv, J A

AU - Grunddal, K V

AU - Schwartz, T W

AU - Füchtbauer, Ernst-Martin

AU - Poulsen, S S

AU - Holst, P J

AU - Holst, Jens Juul

PY - 2013/1/1

Y1 - 2013/1/1

N2 - The enteroendocrine K and L cells are responsible for secretion of glucose-dependent insulinotropic polypeptide (GIP) and glucagon like-peptide 1 (GLP-1), whereas pancreatic α-cells are responsible for secretion of glucagon. In rodents and humans, dysregulation of the secretion of GIP, GLP-1, and glucagon is associated with impaired regulation of metabolism. This study evaluates the consequences of acute removal of Gip- or Gcg-expressing cells on glucose metabolism. Generation of the two diphtheria toxin receptor cellular knockout mice, TgN(GIP.DTR) and TgN(GCG.DTR), allowed us to study effects of acute ablation of K and L cells and α-cells. Diphtheria toxin administration reduced the expression of Gip and content of GIP in the proximal jejunum in TgN(GIP.DTR) and expression of Gcg and content of proglucagon-derived peptides in both proximal jejunum and terminal ileum as well as content of glucagon in pancreas in TgN(GCG.DTR) compared with wild-type mice. GIP response to oral glucose was attenuated following K cell loss, but oral and intraperitoneal glucose tolerances were unaffected. Intraperitoneal glucose tolerance was impaired following combined L cell and α-cell loss and normal following α-cell loss. Oral glucose tolerance was improved following L cell and α-cell loss and supernormal following α-cell loss. We present two mouse models that allow studies of the effects of K cell or L cell and α-cell loss as well as isolated α-cell loss. Our findings show that intraperitoneal glucose tolerance is dependent on an intact L cell mass and underscore the diabetogenic effects of α-cell signaling. Furthermore, the results suggest that K cells are less involved in acute regulation of mouse glucose metabolism than L cells and α-cells.

AB - The enteroendocrine K and L cells are responsible for secretion of glucose-dependent insulinotropic polypeptide (GIP) and glucagon like-peptide 1 (GLP-1), whereas pancreatic α-cells are responsible for secretion of glucagon. In rodents and humans, dysregulation of the secretion of GIP, GLP-1, and glucagon is associated with impaired regulation of metabolism. This study evaluates the consequences of acute removal of Gip- or Gcg-expressing cells on glucose metabolism. Generation of the two diphtheria toxin receptor cellular knockout mice, TgN(GIP.DTR) and TgN(GCG.DTR), allowed us to study effects of acute ablation of K and L cells and α-cells. Diphtheria toxin administration reduced the expression of Gip and content of GIP in the proximal jejunum in TgN(GIP.DTR) and expression of Gcg and content of proglucagon-derived peptides in both proximal jejunum and terminal ileum as well as content of glucagon in pancreas in TgN(GCG.DTR) compared with wild-type mice. GIP response to oral glucose was attenuated following K cell loss, but oral and intraperitoneal glucose tolerances were unaffected. Intraperitoneal glucose tolerance was impaired following combined L cell and α-cell loss and normal following α-cell loss. Oral glucose tolerance was improved following L cell and α-cell loss and supernormal following α-cell loss. We present two mouse models that allow studies of the effects of K cell or L cell and α-cell loss as well as isolated α-cell loss. Our findings show that intraperitoneal glucose tolerance is dependent on an intact L cell mass and underscore the diabetogenic effects of α-cell signaling. Furthermore, the results suggest that K cells are less involved in acute regulation of mouse glucose metabolism than L cells and α-cells.

KW - Animals

KW - Apoptosis

KW - Diphtheria Toxin

KW - Enteroendocrine Cells

KW - Female

KW - Gastric Inhibitory Polypeptide

KW - Gene Knockdown Techniques

KW - Genes, Transgenic, Suicide

KW - Glucagon-Secreting Cells

KW - Glucose

KW - Male

KW - Mice

KW - Mice, Inbred C57BL

KW - Mice, Inbred DBA

KW - Mice, Transgenic

KW - Organ Specificity

U2 - 10.1152/ajpendo.00547.2011

DO - 10.1152/ajpendo.00547.2011

M3 - Journal article

C2 - 23115082

SN - 0193-1849

VL - 304

SP - E60-73

JO - American Journal of Physiology: Endocrinology and Metabolism

JF - American Journal of Physiology: Endocrinology and Metabolism

IS - 1

ER -