Abstract
Recent studies in humans suggest that oral hypoglycemic agents such as tolbutamide (TBA), while lowering blood glucose concentrations, may increase the risk of cardiac death in diabetic patients. The possibility that TBA might adversely influence the cardiotoxicity of isoproterenol (ISO) was studied in adult Long-Evans rats of both sexes. TBA was given po at 500 mg/kg for 30 days; control rats were given vehicle only. On each of Days 29 and 30, ISO was injected sc at doses of 0, 1.0, or 5.0 mg/kg for females and 0, 0.01, and 0.05 mg/kg for males. Surviving rats were sacrificed 24 hr after the last ISO dose, and cardiac lesions were scored histologically for incidence and severity. Mortality after ISO challenge was higher in control groups than in the TBA-treated groups. Body weights were unchanged but absolute heart weights were significantly lower in TBA-treated males after ISO challenge compared with those of control males, and heart-to-body weight ratios were lower in TBA-treated males and females given the high ISO doses. Plasma glucose was lower in TBA-treated rats, but was not affected by ISO in either control or TBA-treated rats. ISO-induced cardiac lesions were similar in both control and TBA-treated rats when related to sex and ISO dose. These data indicate that TBA protects against ISO lethality but does not appear to affect ISO-induced cardiac lesions.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call