OBJECTIVETo compare the effects of high, middle and low doses of enalapril in preventing left ventricular remodeling (LVRM) after acute myocardial infarction (AMI) in rats, especially evaluating the efficacy of low dose enalapril.

METHODSAMI was induced by ligating the left coronary artery in 149 female SD rats. 48 hours after the procedure, the 97 surviving rats were randomized to one of the following four groups: (1) AMI controls (n = 24), (2) high-dose (10 mg x kg(-1) x d(-1), n = 25), (3) middle-dose (1 mg x kg(-1) x d(-1), n = 23), and (4) low-dose (0.1 mg x kg(-1) x d(-1), n = 25) enalapril groups. In addition, sham-operated (n = 13) and normal rats (n = 10) were randomly selected to serve as non-infarction controls. Enalapril was delivered by direct gastric gavage. After 4 weeks of therapy, hemodynamic studies were performed, then the rat hearts were fixed with 10% formalin and pathology analysis was performed. Exclusive of the dead rats and those with MI size < 35% or > 55%, complete experimental data were obtained from 67 rats, which were comprised of (1) AMI controls (n = 13), (2) high-dose enalapril (n = 13), (3) middle-dose enalapril (n = 12), (4) low-dose enalapril (n = 12), (5) sham-operated (n = 8) and (6) normal (n = 9) groups.

RESULTSThere were no significant differences among the four AMI groups in infarction size (all P > 0.05). Compared with the sham-operated group, the left ventricular (LV) end diastolic pressure (LVEDP), volume (LVV), absolute and relative weight (LVAW, LVRW) in AMI group were all significantly increased (all P < 0.001), while maximum LV pressure rising and dropping rates (+/- dp/dt) and their corrected values by LV systolic pressure (+/- dp/dt/LVSP) were all significantly reduced in the AMI control group (P < 0.01 - 0.001), indicating LVRM occurred and LV systolic and diastolic functions were impaired. Compared with the AMI group, LVEDP, LVV, LVAW and LVRW were all significantly decreased in the three enalapril groups (control P < 0.001), with the reduction of LVEDP, LVV and LVAW being more significant in high-dose than in low-dose enalapril groups (all P < 0.05), and the +/- dp/dt/LVSP were significantly increased only in the high and middle-dose enalapril groups (P < 0.01).

CONCLUSIONSHigh, middle and low doses of enalapril were all effective in preventing LVRM after AMI in the rat, with low dose enalapril being effective and high dose superior. As for LV functional improvement, only high and middle-dose enalapril were effective.

Angiotensin-Converting Enzyme Inhibitors ; administration & dosage ; pharmacology ; Animals ; Dose-Response Relationship, Drug ; Enalapril ; administration & dosage ; pharmacology ; Female ; Myocardial Infarction ; physiopathology ; Rats ; Rats, Sprague-Dawley ; Ventricular Remodeling ; drug effects

PURPOSE: The aim of this study was to evaluate the effects of premedication with oral atenolol or enalapril, in combination with remifentanil under sevoflurane anesthesia, on intraoperative blood loss by achieving adequate deliberate hypotension (DH) during orthognathic surgery. Furthermore, we investigated the impact thereof on the amount of nitroglycerin (NTG) administered as an adjuvant agent. MATERIALS AND METHODS: Seventy-three patients undergoing orthognathic surgery were randomly allocated into one of three groups: an angiotensin converting enzyme inhibitor group (Group A, n=24) with enalapril 10 mg, a beta blocker group (Group B, n=24) with atenolol 25 mg, or a control group (Group C, n=25) with placebo. All patients were premedicated orally 1 h before the induction of anesthesia. NTG was the only adjuvant agent used to achieve DH when mean arterial blood pressure (MAP) was not controlled, despite the administration of the maximum remifentanil dose (0.3 microg kg-1min-1) with sevoflurane. RESULTS: Seventy-two patients completed the study. Blood loss was significantly reduced in Group A, compared to Group C (adjusted p=0.045). Over the target range of MAP percentage during DH was significantly higher in Group C than in Groups A and B (adjusted p-values=0.007 and 0.006, respectively). The total amount of NTG administered was significantly less in Group A than Group C (adjusted p=0.015). CONCLUSION: Premedication with enalapril (10 mg) combined with remifentanil under sevoflurane anesthesia attenuated blood loss and achieved satisfactory DH during orthognathic surgery. Furthermore, the amount of NTG was reduced during the surgery.
Administration, Oral ; Adrenergic beta-Antagonists/administration & dosage/*pharmacology ; Adult ; Aged ; *Anesthesia, Inhalation ; Atenolol/administration & dosage/*pharmacology ; Blood Loss, Surgical ; Blood Pressure/drug effects ; Cardiac Output/drug effects ; Double-Blind Method ; Enalapril/administration & dosage/*pharmacology ; Female ; Heart Rate/drug effects ; Humans ; Intraoperative Care ; Male ; Methyl Ethers/*administration & dosage ; Middle Aged ; *Orthognathic Surgical Procedures ; Piperidines/*administration & dosage ; *Premedication ; Treatment Outcome

Previous studies have demonstrated that enalapril and verapamil seem to attenuate the cyclosporine nephrotoxicity. However, the mechanisms have not been completely understood, especially on molecular events. The aim of this study was to examine the effect of individual or combined treatment on osteopontin, TGF-beta, endothelin-1 and procollagen alpha 1(I) mRNA expressions. Enalapril (50 mg/L in drinking water) and verapamil (0.5 mg/kg/day, subcutaneously), alone or in combination, were administered to rats with chronic cyclosporine nephrotoxicity (cyclosporine, 25 mg/kg/day, subcutaneously) (n = 5 each). Five rats treated with olive oil vehicle were used as control. After 4 weeks, biochemical parameters were measured, and renal cortical mRNA levels were evaluated by Northern blot analysis. Cyclosporine reduced renal creatinine clearance significantly and induced renal cortical osteopontin, TGF-beta, endothelin-1 and procollagen alpha 1(I) gene expressions around 13.5 +/- 1.3, 2.4 +/- 0.2, 1.5 +/- 0.1, 1.9 +/- 0.1 folds, respectively. Individual treatment with enalapril or verapamil significantly suppressed the osteopontin and TGF-beta mRNA expression, but not endothelin-1 and procollagen alpha 1(I). Combined treatment also inhibited the osteopontin and TGF-beta mRNA expression but there was no difference between combined and individual treatment. In conclusion, enalapril or verapamil significantly blunted the cyclosporine-induced osteopontin and TGF-beta gene expressions. However, combined treatment did not show any additive effect.
Angiotensin-Converting Enzyme Inhibitors/therapeutic use* ; Animal ; Calcium Channel Blockers/therapeutic use* ; Cyclosporine/adverse effects ; Drug Therapy, Combination ; Enalapril/therapeutic use* ; Enalapril/administration & dosage ; Endothelin-1/metabolism ; Endothelin-1/genetics ; Gene Expression Regulation/drug effects ; Immunosuppressive Agents/adverse effects ; Kidney Cortex/metabolism ; Male ; Nephritis/drug therapy* ; Nephritis/chemically induced ; Procollagen/metabolism ; Procollagen/genetics ; RNA, Messenger/analysis ; Rats ; Rats, Wistar ; Sialoglycoproteins/metabolism ; Sialoglycoproteins/genetics ; Transforming Growth Factor beta/metabolism ; Transforming Growth Factor beta/genetics ; Verapamil/therapeutic use* ; Verapamil/administration & dosage

PURPOSE: To evaluate the effects of angiotensin-converting enzyme inhibitors (ACE-I) in retarding progression of severe non-proliferative diabetic retinopathy (NPDR) in normotensive type 2 diabetic patients. METHODS: This was a retrospective case control study of 128 patients with normotensive type 2 diabetes with lower than +1 dipstick proteinuria and severe NPDR who were classified into either an ACE-I treated group (Enalapril maleate 10 mg, n=12 , Ramipril 5 mg, n=17) or an ACE-I untreated group (n=99). Medical records were reviewed for endpoints of (a) occurrence of proliferative diabetic retinopathy (PDR) or macular edema (ME) for which laser phototherapy was necessary or (b) development of proteinuria of higher than +1 level requiring medication of ACE-I. RESULTS: From the total of 128 patients, there were 29 ACE-I treated patients and 99 ACE-I untreated patients. There were no differences in the average age, duration of diabetes, body mass indices, blood pressure and levels of hyperglycemia or HbA1C between the two groups. Blood pressure and HbA1C levels in both groups remained unchanged during the study. The mean follow-up period was 41.6 months. In the ACE-I group, 6 patients progressed to PDR, 5 to ME and 6 developed proteinuria of greater than +1 over the follow-up period. In the control group, 30 patients progressed to PDR, 6 to ME and 9 developed proteinuria of greater than +1 over the follow-up period. CONCLUSIONS: Small doses of ACE-I did not yield any beneficial effects in retarding the progression of severe NPDR.
Treatment Failure ; Severity of Illness Index ; Retrospective Studies ; Ramipril/administration & dosage/*therapeutic use ; Middle Aged ; Male ; Humans ; Fundus Oculi ; Female ; Enalapril/administration & dosage/*therapeutic use ; Dose-Response Relationship, Drug ; Disease Progression ; Diabetic Retinopathy/*drug therapy/pathology ; Diabetes Mellitus, Type 2 ; Case-Control Studies ; Angiotensin-Converting Enzyme Inhibitors/administration & dosage/*therapeutic use ; Aged

AIMTo study the plasma angiotensin II (Ang II) levels and the expressions of angiotensin II1 receptor (AT1) in blood vessels and kidneys in diabetic and high fat diet rats, and the effects of enalapril on plasma Ang II levels and the expressions of AT1 in blood vessels and kidneys in diabetic rats.

METHODSThe plasma Ang II level was assayed with 125I-Ang II radioimmunoassay, and the expression of AT1 in blood vessel and kidney was analyzed with immunohistochemical technique.

RESULTSThe plasma Ang II level was significantly higher in type 2 diabetic rats (241 +/- 49) pg x mL(-1) than that in the control (71 +/- 22) pg x mL , high fat diet group (151 +/- 29) pg x mL(-1) (P < 0.01) , and enalapril-treated groups (136 +/- 25) pg x mL(-1) (P < 0.05). The plasma Ang II levels in high fat diet and in enalapril-treated groups were also significantly higher than that in control group ( P < 0.01 ). With immunohistochemical technique, it was found that the expression of AT1 in endothelial cells of blood vessels, vascular smooth muscle cells, and kidneys in diabetic group increased. The expression of AT1 in endothelial cells of blood vessels, vascular smooth muscle cells, and kidney in enalapril-treated group was similar to that in control group.

CONCLUSIONThe plasma Ang II levels and the expression of AT1 in type 2 diabetic and high fat diet rats increased. Enalapril was shown to decrease the plasma Ang II level and downregulate the expression of AT1 in blood vessels and kidneys in type 2 diabetic rats.

Angiotensin II ; blood ; Angiotensin-Converting Enzyme Inhibitors ; pharmacology ; Animals ; Blood Vessels ; cytology ; metabolism ; Diabetes Mellitus, Type 2 ; blood ; metabolism ; Dietary Fats ; administration & dosage ; Enalapril ; pharmacology ; Endothelial Cells ; metabolism ; Kidney ; metabolism ; Male ; Myocytes, Smooth Muscle ; metabolism ; Rats ; Rats, Sprague-Dawley ; Receptor, Angiotensin, Type 1 ; metabolism