Gastric neuropeptides and gastric motor abnormality in streptozotocin-induced diabetic rats: observation for four weeks after streptozotocin.
Alterations of gastric calcitonin gene-related peptide and substance P content and gastric emptying in early stages of streptozotocin-induced diabetic rats were investigated. Diabetes was induced by intravenous injection of streptozotocin (50 mg/kg) in male Wistar rats. Gastric emptying of phenol red solution and calcitonin gene-related peptide and substance P content of gastric walls, measured by radioimmunoassay, was assessed two and four weeks after streptozotocin injection. Gastric emptying two weeks after streptozotocin was delayed (32+/-9%) and that four weeks after was enhanced (73+/-2%) compared with nondiabetic control rats (50+/-3%). Calcitonin gene-related peptide content of the gastric antrum and corpus was increased two weeks after and decreased four weeks after streptozotocin, while gastric substance P content was not changed at any time in diabetic rats. Insulin treatment reversed alterations of gastric emptying and calcitonin gene-related peptide content. The delayed gastric emptying in two-week diabetic rats was reversed by CGRP antagonist and the enhanced gastric emptying in four-week diabetic rats was reversed by CGRP pretreatment. These results suggest a possible relationship between gastric calcitonin gene-related peptide and abnormal gastric motility in diabetic state.
Miyamoto
Y
Y
Second Department of Medicine, Asahikawa Medical College, Japan.
Yoneda
M
M
Morikawa
A
A
Itoh
H
H
Makino
I
I
D000818:Animals; D015740:Calcitonin Gene-Related Peptide / Q000378:metabolism*; D003921:Diabetes Mellitus, Experimental / Q000188:drug therapy / Q000378:metabolism / Q000503:physiopathology*; D005746:Gastric Emptying; D005753:Gastric Mucosa / Q000378:metabolism*; D007328:Insulin / Q000627:therapeutic use; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D013311:Streptozocin; D013373:Substance P / Q000378:metabolism*; D013997:Time Factors
D007328:Insulin; D013373:Substance P; D013311:Streptozocin; D015740:Calcitonin Gene-Related Peptide