Celiprolol versus metoprolol and propranolol on vascular reactivity and serum lipid profile in experimental animals

In the present study, the effects of the 2 cardioselective beta-adrenoceptive blockers; celiprolol and metoprolol on serum lipid profile and on the isolated aortic strip were investigated in comparison with the standard non-selective beta-blocker propranolol. The influence of the 3 beta-blockers on serum lipid profile was determined by measuring the total triglycerides [TG], total cholesterol [TG,], high density lipoprotein cholesterol [HDL-C], and low density lipoprotein cholesterol [LDL-C] in serum of adult male albino rats. Celiprolol [40 mg/kg] metoprolol [l0 mg/kg,]; and propranolol [10mg/kg]; were given orally once daily to adult rats for 2 months. Statistical analysis of the results revealed that celiprolol significantly decreased the serum levels of TG; TC; LDL-C; and significantly increased HDL-C serum levels. While, metoprolol induced insignificant changes in serum lipid profile. On the other hand, propranolol was found to significantly increase LDL-G; TG; and TC levels, while it significantly decreased HDL-C level. On the isolated rabbit aortic strip, the addition of celiprolol [l6ug/ml bath] was found to significantly decrease the contractile response of the aortic strip to different concentrations of phenylephrine. Metoprolol and propranolol, on the other hand, were found to induce insignificant changes on the contractile responses of the isolated rabbit aortic strip to phenylephrine. So, celiprolol might be a suitable alternative to the currently used cadioselective BB; when the issues of hyperlipidemia and quality of life are to be dealt with in a hypertensive cardiac patient

Comparative study of the antihypertensive and metabolic effects of the angiotensin II antagonist valsartan versus captopril in rats

Angiotensin II is a key hormone of the renin-angiotensin system which regulates blood pressure. Valsartan is a highly selective and specific direct angiotensin II antagonist. It inhibits angiotensin II binding to the angiotensin II receptor subtype ATI and blocks the pressor effect of angiotensin II in a dose-dependent manner. This study was conducted to evaluate the antihypertensive effect of valsartan comparing it to the converting enzyme inhibitor captopril, as well as their effect on glucose and insulin levels in blood of fasting rats. 70 adult albino rats were used in this study. Captopril and valsartan were given to 2 groups of rats [each of 10 rats] in a dose of 3 mg/kg orally daily for 3 weeks to study their effect on serum glucose and insulin levels in normal fasting adult rats .It was found that captopril significantly decreased serum glucose values from 91.4 [3.92 to 75.9 [0.48 [p<0.05]; while it significantly increased serum insulin values from 11.45 [1.2 to 15.97[0.48 [p< 0.05]. On the other hand, valsartan induced insignificant changes in either glucose or insulin values. It was found that valsartan has approximately an equipotent antihypertensive effect compared to captopril in the 2-kidney-One clip adult hypertensive rats, when given daily orally for 4 weeks. Captopril significantly decreased the systolic blood pressure from 167.7[3.4 to 140.9 [2.7 with 15.98% reduction [P< 0.001] by the end of the 4th week; while valsartan also significantly decreased the systolic blood pressure from 166.54.2 to 145.62.5 [p< 0.001] with 12.55% reduction at the end of the 4th week. In renal hypertensive rats [2K-IC] pretreated by hydrochlorothiazide [2.25mg/kg b.w.] orally daily for 3weeks, captopril induced a sharp significant drop of blood pressure when given orally as a single dose [5mg/kg b.w.] especially in the first hour, from 148.3[2.1 to 132.7[3.1 with 10.5% reduction [p< 0.001]. On time other hand. valsartan, induced a slow non-significant fall of blood pressure after the same period with the same dose and route of administration, from 147.9[3.1 to 141.7[3.2 with 4.19% reduction, [p> 0.05]. It is concluded that valsartan could replace angiotensin converting enzyme inhibitors in patients who are liable to suffer from angioedema or could not tolerate dry persistent cough Associated with, the increase of bradykinin and prostaglandin levels following ACEIs administration. The lack of time first dose phenomenon as reported by this investigation, could be an added advantage of valsartan over captopril. Also, because at the lack of adverse metabolic effects on glucose tolerance valsartan could prove to be the second choice drug in diabetic hypertensive patients who could not tolerate ACEIs