Experimental diabetes induces an early change in the level of the G-protein subunit, alpha i2, in rat intestinal mucosa.
This study was undertaken to investigate the consequences of diabetes on Gi-protein expression and alpha 2-adrenergic receptivity in rat intestinal mucosa. Experimental diabetes was induced by treatment with streptozotocin. Quantification of alpha i-subunits by immunoblotting demonstrated that the level of the G alpha i2 but not the G alpha i3 subunit was markedly decreased in jejunum and colon membranes from diabetic rats as compared to controls. Parallel assessment of sympathetic innervation was performed by determination of norepinephrine content, measurement of tyrosine hydroxylase and monoamine oxidase activities, and quantification of alpha 2-adrenergic receptors in the different segments. At this stage of diabetes (6 weeks after streptozotocin injection), none of these parameters was significantly modified. Consequently, the decrease in G alpha i2 amount appears to be independent of the neuropathy describe in later stages of diabetes.
Lacombe
C R
CR
INSERM U 317, Institut Louis Bugnard, CHU Rangueil, Toulouse, France.
Viallard
V P
VP
Schaak
S A
SA
Paris
H J
HJ
D000818:Animals; D002395:Catecholamines / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D003106:Colon; D003921:Diabetes Mellitus, Experimental / Q000378:metabolism* / Q000503:physiopathology; D004386:Duodenum; D019204:GTP-Binding Proteins / Q000096:biosynthesis*; D007413:Intestinal Mucosa / Q000294:innervation / Q000378:metabolism*; D007583:Jejunum; D046911:Macromolecular Substances; D008297:Male; D008995:Monoamine Oxidase / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D012016:Reference Values; D014446:Tyrosine 3-Monooxygenase / Q000378:metabolism
D002395:Catecholamines; D046911:Macromolecular Substances; D014446:Tyrosine 3-Monooxygenase; D008995:Monoamine Oxidase; D019204:GTP-Binding Proteins