Ace elisa kit

Rat angiotensin-converting enzyme (ACE) ELISA kit was purchased
from Cusabio, Houston. Lisinopril was obtained from Global Napi Pharmaceuticals,
Cairo, Egypt. N(γ)-nitro-l-arginine methyl ester (l-NAME), vanadium trichloride, absolute ethanol, malondialdehyde
(MDA), Ellman’s reagent, sodium nitrite, sulfanilamide, thiobarbituric
acid, trichloroacetic acid, and N-(1-naphthyl)ethylenediamine
dihydrochloride (NEDD) were all obtained from Sigma-Aldrich, St. Louis,
Missouri. Dipotassium hydrogen phosphate and potassium dihydrogen
phosphate were purchased from Sisco, India. Tween 80, umbelliferone,
and LC-MS-grade analysis solvent were obtained from Sigma-Aldrich,
Germany. All other chemicals used were of highest analytical grade.

An angiotensin-converting enzyme
concentration was estimated using rat angiotensin-converting enzyme
(ACE) ELISA kit from Cusabio, Houston, according to the manufacturer’s
protocol based on the competitive inhibition enzyme immunoassay technique.
A standard curve was constructed by plotting the absorbance on y-axis against the ACE concentration (pg/mL) on x-axis with concentrations ranging from 156 to 2500 pg/mL.
The standard curve was used to determine the ACE concentration (pg/mL)
in the samples.