چكيده لاتين :
To evaluate the acute effect of lovastatin on diabetic endothelial dysfunction, we examined
this effect on the aortic rings of streptozotocin-diabetic rats. The endothelial function was
assessed in aortic rings isolated from diabetic rats, 12 weeks after treatment with streptozotocin
(45 mg/kg, i.p.). The concentration-response curve to acetylcholine (Ach) in the aortic rings
precontracted with phenylephrine (10 -6 M) was significantly diminished in diabetic groups; and
maximum relaxation in control and diabetic groups were 82(PLUS-MINUS)1.93% and 48(PLUS-MINUS)2.39% respectively
(a 42% decrease, P(LESS THAN)O.OOI). Incubation with lovastatin (10-SM) for 10 min, significantly
improved the Ach-induced relaxation of diabetic groups and the maximum relaxation increased
to 74.2 (PLUS-MINUS)3.3% (a 54% increase, P(LESS THAN)O.OOI).
Incubation with NO -nitro-L-arginine methyl ester hydrochloride (L-NAME; 5xlO -7 M) for
20 min eliminated a significant difference in Ach - induced relaxation responses in diabetic and
control groups and also eliminated the improving effect of lovastatin in diabetic groups. On
the other hand 10 min incubation with indomethacin (10-s M) did not eliminate the difference
in Ach-induced relaxation responses in diabetic and control groups and also did not eliminate
the improving effect of lovastatin in diabetic groups. Lovastatin did not modify sodium
nitroprosside-induced relaxation in either diabetic or control groups and also did not induce any
direct relaxation.
Therefore, it is concluded that incubation of aortic rings with lovastatin significantly
improves endothelium-dependent relaxation in diabetic groups by increasing the nitric oxide
bioavailability, most probably due to itsי antioxidant effects.
