Effects of Taurine on Myocardial cGMP/cAMP Ratio, Antioxidant Ability, and Ultrastructure in Cardiac Hypertrophy Rats Induced by Isoproterenol - Advances in Experimental Medicine and Biology - page 205

ice-cold physiological saline, and weighted; then the heart coefficient (the ratio of
heart weight to body weight) was calculated.

21.2.4 Sample Collection and Biochemical Analysis

Blood samples were collected from jugular vein; sera were separated from the
blood immediately and frozen at −80°C until assayed. Serum CK-MB level
was measured with a commercial kit according to the manufacture's recom-
mendations. The optical density at 450 vnm was recorded by using enzyme-
labelled meter (Thermo, USA). Serum antioxidant enzymes (GSH, SOD,
GSH-Px, and T-AOC) activities and MDA level were determined by colorime-
try using kits on spectrophotometry according to the procedure provided,
respectively.
After weighing, the ventricular myocardium was separated from the heart,
frozen in liquid nitrogen, and stored at −80°C for further biochemical analysis.
Frozen myocardial tissue samples were homogenated in cold physiological
saline; myocardial antioxidant enzymes (GSH, SOD, GSH-Px, and T-AOC)
activities and MDA level were determined by colorimetry using kits on spectro-
photometry. Myocardial cGMP and cAMP levels were measured by ELISA tech-
nique based on the introduction of reagent kits. Myocardial content of TP was
also determined by colorimetry using Coomassie brilliant blue as the visualiza-
tion reagent.

21.2.5 Transmission Electron Microscope Analysis

Hearts were excised rapidly; the apex of the heart was quickly cut into 1mm 3 or
1 cubic millimeter pieces on a dry ice-cooled sample plate, then transferred to vials
containing 2% glutaraldehyde, and stored at 4°C for further ultrastructure analysis.
Seven days later, the tissue samples were postosmicated with 2% osmium tetroxide
solution and dehydrated in ethanol series and embedded in epoxy resin. Sections
were viewed by transmission electron microscope, JEM-1200EX (JEOL, Japan), at
a magnification of ×8,000-15,000.

21.2.6 Statistical Analysis

Data were presented as the mean ± SEM and significant differences were determined
by Duncan's multiple range test using SPSS 16.0 statistical analysis software.
P value less than 0.05 was considered significant.