Characterization of CS-045, a new oral antidiabetic agent, II. Effects on glycemic control and pancreatic islet structure at a late stage of the diabetic syndrome in C57BL/KsJ-db/db mice.
Antidiabetic effects of CS-045 were evaluated in 5-month-old C57BL/KsJ-db/db mice (db/db). CS-045 administered for 3 weeks to diabetic db/db mice as a 0.2% food admixture improved hyperglycemia (855 +/- 25 v 298 +/- 62 mg/dL, P less than .01) and glucose intolerance, and lowered plasma triglyceride (299.6 +/- 28.7 v 76.3 +/- 20.7 mg/dL, P less than .01) and free fatty acid (FFA) levels (1.16 +/- 0.14 v 0.57 +/- 0.07 mEq/L, P less than .01). Food intake was not changed, while a small but significant increase in body weight was observed in CS-045-treated mice. Plasma insulin levels gradually increased after 5 days of CS-045 treatment, and a nonsignificant increase was observed in plasma insulin levels after 3 weeks (1.85 +/- 0.50 v 4.54 +/- 1.47 mg/mL). In contrast, the plasma glucagon levels decreased after 3 weeks of CS-045 treatment. Histological examination by aldehyde-fucshin staining demonstrated that pancreatic beta cells in CS-045-treated db/db mice were heavily regranulated, whereas most of the beta cells were extensively degranulated in nontreated db/db mice. The heavily regranulated state of beta cells was also compatible with an increase in pancreatic insulin content in CS-045-treated db/db mice. Electron microscopic analysis showed a well-developed endoplasmic reticulum and the accumulation of much amorphous structural material in the intracisternal space of beta cells from CS-045-treated db/db mice, which were suggestive of an increase in insulin synthesis. Moreover, CS-045 treatment decreased exocrine-containing islets, which was associated with the islets' degeneration process. Immunohistochemical staining of islets showed that CS-045 treatment normalized the distribution pattern of endocrine cells in the islets of db/db mice, reflected by a predominantly peripheral location of alpha and delta cells.(ABSTRACT TRUNCATED AT 250 WORDS)
Biological Research Laboratories, Sankyo Company, Ltd., Tokyo, Japan.
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T
Fujiwara
M
M
Wada
K
K
Fukuda
M
M
Fukami
S
S
Yoshioka
T
T
Yoshioka
H
H
Horikoshi
D000284:Administration, Oral; D000818:Animals; D001786:Blood Glucose / Q000032:analysis*; D002839:Chromans / Q000494:pharmacology*; D003920:Diabetes Mellitus / Q000097:blood* / Q000235:genetics / Q000473:pathology; D005934:Glucagon / Q000032:analysis; D006943:Hyperglycemia / Q000097:blood* / Q000235:genetics / Q000473:pathology; D006946:Hyperinsulinism / Q000097:blood* / Q000235:genetics / Q000473:pathology; D007004:Hypoglycemic Agents / Q000494:pharmacology; D007328:Insulin / Q000032:analysis; D007515:Islets of Langerhans / Q000473:pathology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D010179:Pancreas / Q000737:chemistry; D013844:Thiazoles / Q000494:pharmacology*; D045162:Thiazolidinediones; D000077288:Troglitazone
D001786:Blood Glucose; D002839:Chromans; D007004:Hypoglycemic Agents; D007328:Insulin; D013844:Thiazoles; D045162:Thiazolidinediones; D005934:Glucagon; D000077288:Troglitazone