Morphological changes in the rat endocrine pancreas within 12 h of intravenous streptozotocin administration.
We examined early morphological changes in pancreatic endocrine cells within 12 h of intravenous streptozotocin (STZ) administration (60 mg/kg). Thirty rats were allocated either to a control group (vehicle alone) or to one of four experimental groups tested after 3, 6, 9 and 12 h. Karyopyknosis and cytoplasmic vacuoles were first observed in beta-cell cytoplasm 3 h after STZ administration (STZ-3 h), and the most severe damage was found in beta cells at STZ-12 h. Insulin-positive non-islet cells were observed near the intercalated duct (ICD) and/or centroacinar (CA) cells at STZ-6 h and their numbers peaked at STZ-6 h. The distribution patterns of the insulin-positive cells and those of nestin and insulin-like growth factor-1 were similar and their nuclei were positive for proliferating cell nuclear antigen. Thus, ICD cells and/or CA cells reacted immediately to transform into insulin-secreting cells to replace injured beta cells (or to compensate for the lack of beta cells) within 12 h of STZ administration.
Nagasao
J
J
Department of Veterinary Anatomy, School of Veterinary Medicine and Animal Sciences, Kitasato University, Towada-shi, Aomori 034-8628, Japan.
Yoshioka
K
K
Amasaki
H
H
Tsujio
M
M
Ogawa
M
M
Taniguchi
K
K
Mutoh
K
K
D000818:Animals; D001786:Blood Glucose / Q000378:metabolism*; D003921:Diabetes Mellitus, Experimental / Q000139:chemically induced / Q000378:metabolism / Q000473:pathology*; D007150:Immunohistochemistry; D007328:Insulin / Q000097:blood / Q000378:metabolism*; D007515:Islets of Langerhans / Q000187:drug effects / Q000378:metabolism / Q000473:pathology*; D007700:Kinetics; D008297:Male; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D013311:Streptozocin / Q000633:toxicity
D001786:Blood Glucose; D007328:Insulin; D013311:Streptozocin