These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Insulin-induced normoglycemia improves ischemic outcome in hyperglycemic rats.
    Author: Warner DS, Gionet TX, Todd MM, McAllister AM.
    Journal: Stroke; 1992 Dec; 23(12):1775-80; discussion 1781. PubMed ID: 1448829.
    Abstract:
    BACKGROUND AND PURPOSE: Hyperglycemia is known to aggravate ischemic brain damage. This study sought to determine if preischemic insulin-induced normoglycemia would improve outcome in hyperglycemic rats. METHODS: Normal rats and rats with 5-7 days of streptozotocin-induced diabetes were studied. Normal rats served as either fasted normoglycemic controls or dextrose-infused (hyperglycemic) controls. In the acutely diabetic rats either no insulin was given or insulin was given at 30 or 90 minutes before ischemia so as to induce preischemic normoglycemia. All rats underwent 10 minutes of forebrain ischemia. After 5 days of recovery, motor function and histological outcome were assessed. RESULTS: Untreated diabetic rats and dextrose-infused control rats had greater hippocampal CA1 damage than normoglycemic control rats. In contrast, insulin-treated diabetic rats had less hippocampal CA1 damage than either untreated diabetic rats or dextrose-infused control rats. Injury in the two insulin-treated groups was not significantly different from that in the normoglycemic control group (all three groups had plasma glucose values of 120-150 mg/dl immediately prior to ischemia). Despite similar plasma glucose values (300-400 mg/dl), fewer postischemic seizures (0% versus 67%) were observed in the untreated diabetic group than in the dextrose-infused control group (p < 0.001). CONCLUSIONS: Hyperglycemia caused by either dextrose infusion or streptozotocin-induced diabetes resulted in exacerbated ischemic brain damage. Insulin therapy to rapidly induce preischemic normoglycemia improved outcome from forebrain ischemia in the acutely diabetic rats. Glucose-infused hyperglycemic rats frequently exhibited postischemic generalized seizures while acutely diabetic rats did not. The latter results implicate some adaptive/protective mechanism associated with acute streptozotocin-induced diabetes that results in a decreased sensitivity to hyperglycemia-augmented ischemic brain damage.
    [Abstract] [Full Text] [Related] [New Search]