Protective Effects of Tirofiban on Myocardial Ischemia-Reperfusion Injury in Rabbits.

We aimed to explore the different protective effects of tirofiban on myocardial ischemia-reperfusion (IR) injury in New Zealand white rabbits by comparing the results from different administration methods. Fifty New Zealand white rabbits were randomly divided into a sham group (group A, n = 10) and four IR groups (group B, IR group with injection of physiological saline; group C, tirofiban administered through marginal ear vein after reperfusion; group D, tirofiban injected through coronary ostia before reperfusion; group E, tirofiban injected through coronary artery after blood flow restoration; all n = 10). Myocardial IR injury models were prepared in IR groups. An automatic biochemical analyzer (HITACHI 7020, Japan) was applied for testing serum creatine kinase-MB levels. The myeloperoxidase activity, malondialdehyde levels, nitric oxide synthase activity, and nitric oxide (NO) volume were detected 180 minutes after reperfusion. The myocardial apoptosis was identified using the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling technique, and the protein expressions of B-cell lymphoma-2, Bcl-2 associated X, and aquaporin-1 were measured through Western blot. The highest and lowest ST-segment resolution among the IR groups was observed in groups E and B, respectively. The creatine kinase-MB levels at 60, 120, and 180 minutes in group E was greatly decreased than in groups B, C, and D. Compared with the sham group, the IR groups demonstrated evidently elevated myeloperoxidase activity, malondialdehyde levels, inducible NOS activity, NO volume, myocardial apoptotic index, and aquaporin-1 expressions; among the IR groups, these indicators were increased and decreased most in groups B and E, respectively. The B-cell lymphoma-2/Bcl-2 associated X ratio in the IR groups were evidently higher than the sham group, with the highest and lowest rate in groups E and B, respectively. Tirofiban injection through coronary artery after blood flow restoration has a better protective effect against myocardial IR injury than tirofiban administration through coronary ostia before reperfusion and tirofiban injection through the auricular vein after reperfusion.

[Increased autoantibody production against AT(1)-receptors and alpha(1)-adrenergic receptors in hypertensive patients].

OBJECTIVE: To observe autoantibodies production against AT(1)-receptors and alpha(1)-adrenergic receptors and association to risk factors, such as sex, age, family history, course of hypertension and other cardiovascular diseases in hypertensive patients. METHODS: A total of 690 patients with essential hypertension admitted to our hospital were selected and autoantibodies against AT(1)-receptors and alpha(1)-adrenergic receptors were detected by ELISA. Multiple logistic regression analysis was performed based on obtained data. RESULTS: Positive rates for antibody against AT(1)-receptors and alpha(1)-adrenergic receptors were 47.1% (325/690) and 36.4% (251/690) respectively in this group of patients. Duration of hypertension history was significantly longer in the antibody against AT(1)-receptors and alpha(1)-adrenergic receptors positive groups [(9.3 +/- 11.0) year, (9.9 +/- 11.1) year] compared to the negative groups [(7.3 +/- 9.3) year, (7.2 +/- 9.5) year, all P < 0.01]. The ratio of family history with hypertension was also significantly higher in antibody positive groups than negative ones (47.69% vs 39.18%, P < 0.01). Regression analysis demonstrated that 5 risk factors were related to positive production of autoantibody against AT(1)-receptors including female gender, age, family history, duration of hypertension history and diabetes. However, just age, family history, duration of hypertension history were main factors responsible to the production of autoantibody against alpha(1)-adrenergic receptors (all P < 0.05). CONCLUSION: The environmental and genetic factors contributed to the autoantibody production in patients with essential hypertension.

[Association between positive autoantibodies against AT1-receptor and cardiac remodeling in patients with hypertension].

OBJECTIVE: To observe the association between positive autoantibodies against AT(1)-receptor and cardiac remodeling in primary hypertensive patients. METHODS: Echocardiography was performed and serum autoantibodies against AT(1)-receptor were detected by enzyme linked immunosorbent assay (ELISA) in 592 patients with primary hypertension. The differences on blood pressure level, course of hypertension, vasoactive substance and echocardiography parameters between the positive group and negative group were compared. Factors related to left ventricular enlargement were analyzed by multiple logistic regressions. RESULTS: The positive percentage of autoantibodies against AT(1)-receptor was 38.0% (225/592). End-diastolic right atrial and left ventricular diameters in positive group were significantly larger than that in negative group (P = 0.049 and P = 0.044, respectively). Regression analysis demonstrated that positive autoantibodies against AT(1)-receptor, male gender, diastolic blood pressure and course of hypertension were related to left ventricular enlargement (all P < 0.05). CONCLUSION: The autoantibodies against AT(1)-receptor is associated with left ventricular and right atrial enlargement in hypertensive patients.

[Autoantibodies against alpha1 adrenergic receptor related with cardiac remodeling in hypertensive patients by clinical observation].

OBJECTIVE: To investigate the effects of autoantibodies against alpha(-) adrenergic receptor on cardiac remodeling in patients with hypertension. METHODS: Five hundred and fifty three patients with hypertension in our hospital were selected. The autoantibodies against alpha(1) adrenergic receptor in sera of donor were detected by ELISA, and the results of echocardiography were recorded. By multiple logistic regressions, the risk factors were analyzed on left ventricular enlargement of hypertension. RESULTS: The percentage of autoantibodies against alpha(1) adrenergic receptor positive was 32.3% (179/553). There were significant difference between the positive group and negative group on the ratio of left atrial enlargement (53.6%, 44.3%, respectively; P < 0.05) and left ventricular enlargement (12.8%, 6.1%, respectively; P < 0.01). The result of regression analysis demonstrated that 4 risk factors were related to left ventricular enlargement, including male, course of disease, heart rate (HR) and autoantibodies against alpha(1) adrenergic receptor in the serum (all P < 0.05). CONCLUSIONS: The autoantibodies against alpha(1) adrenergic receptor have a relationship with left ventricular enlargement of hypertension. Patients with the activity of autoantibodies against alpha(1) adrenergic might contribute to predict cardiac remodeling.