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E Scalbert

Publications and source records attributed to E Scalbert.

At least 37 records · Page 2Linked to original sources

Prevention of endothelial dysfunction in small and large arteries in a model of chronic heart failure. Effect of angiotensin converting enzyme inhibition.

Chronic heart failure (CHF) impairs endothelium-dependent vasodilatation of large conductance arteries. We investigated whether a similar reduction also occurs in small arteries, and whether such a reduction can be prevented by the angiotensin converting enzyme inhibitor perindopril (P) in a rat model of CHF (left coronary artery ligation). After 1 month treatment with placebo or P (2 mg/kg/day), rats were anesthetized and arterial pressure, left ventricular end-diastolic pressure, and central venous pressure were measured with a micromanometer. Segments of aorta and mesenteric artery (mean diameter, 281 +/- 8 microns) were then isolated, cannulated, and perfused at constant pressure using an arteriograph. Responses to increasing concentrations of acetylcholine (Ach), nitroprusside, and to 10(-4) mol/L NG-nitro-L-arginine methyl ester (L-NAME) were studied after preconstriction by phenylephrine. Heart failure resulted in a decrease in systolic and diastolic pressures, an increase in left ventricular end-diastolic and central venous pressures, and a significant depression of Ach-induced dilatation of the mesenteric artery (maximal dilatation, from 90 +/- 4% to 63 +/- 4%, P < .05) but not of the aorta (from 56 +/- 8% to 45 +/- 5%, NS) without any modification in the endothelium-independent vasodilatation induced by nitroprusside. In the group treated by the angiotensin converting enzyme (ACE) inhibitor perindopril, systolic and diastolic pressures were slightly decreased, whereas left ventricular end diastolic, central venous pressures, and the endothelium-dependent vasodilating response to Ach were normalized. Responses to L-NAME were not affected by CHF or perindopril. Perindopril also decreased hypertrophy, as evidenced by a significantly lower heart weight in treated rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiotensin-Converting Enzyme Inhibitors↗

Relations between myocardial contractility, myosin phenotype, and plasma angiotensin-converting enzyme activity in the cardiomyopathic hamster.

Angiotensin-converting enzyme (ACE) inhibitors have been shown to preserve myocardial contractility in the cardiomyopathic Syrian hamster (CSH). To determine if this was related to changes in myosin heavy-chain (MHC) phenotype, myosin isoform patterns and mechanical properties were studied in the same left ventricular papillary muscle from CSH of the Bio 53.58-dilated strain. From age 1 to 6 months, 22 CSH randomly received either perindopril 1 mg/kg/day in distilled water (PE, n = 11) or distilled water only (PL, n = 11), and seven control golden Syrian hamsters (C) received distilled water by force-feeding. Compared to C, PL had a lower Vmax (p < 0.01), a lower amount of alpha-MHC (p < 0.01), and an unchanged twitch duration. In PE, as compared to PL, there was a higher Vmax (p < 0.05), a higher alpha-MHC (p < 0.05), and an unchanged twitch duration. There was a positive relationship between Vmax and alpha-MHC in the population taken as a whole (p < 0.01), and when muscles from C and PL groups were plotted together (p < 0.001), but neither within each group, nor when PL and PE were plotted together. Our study indicates that in CSH (a) the preserved contractility with ACE-inhibitor treatment is associated with limitation of isomyosin shift induced by the myopathic process, but no cause-to-effect relationship could be demonstrated on the basis of our data, and (b) adaptive changes in twitch duration were not observed either in untreated CSH or in perindopril-treated CSH, despite significant changes in alpha-MHC content.

Animals↗

Sarcoplasmic reticulum Ca2+ pumps in heart and diaphragm of cardiomyopathic hamster: effects of perindopril.

The polymyopathy of the Syrian hamster is associated with alterations of cellular calcium regulation and contractile performance of cardiac and skeletal muscles and, in particular, the diaphragm. Angiotensin-converting enzyme (ACE) inhibitors have been shown to preserve contractile performance. Therefore we analyzed the expression of the genes coding for the sarco(endo)plasmic reticulum Ca(2+)-adenosinetriphosphatase (SERCA) in heart and diaphragm of the cardiomyopathic Syrian hamster (CSH) from the dilated strain Bio 53-58, and we tested the influence of ACE inhibition on accumulation of the different SERCA mRNAs. In the diaphragm of healthy hamsters, two SERCA mRNA isoforms were present: SERCA 1 and SERCA 2. At 6 mo of age, the myopathic process resulted in decreased levels of SERCA 1, whereas the level of SERCA 2 was unchanged. The ACE inhibitor perindopril (1 mg.kg-1.day-1), administered by force feeding from 1 to 6 mo of age, had no effect on the SERCA 1 mRNA level. In heart, the myopathy was associated with a depressed level of SERCA 2 mRNA in 9- but not in 6-mo-old animals. Perindopril treatment from 6 to 9 mo reversed cardiac hypertrophy and the relative decrease in SERCA 2 mRNA level. Preventive treatment with perindopril from 1 to 9 mo tended to prevent (not significantly) the development of cardiac hypertrophy and reduction in SERCA gene expression. In conclusion, the myopathic process affects SERCA gene expression in the diaphragm and subsequently in the heart. Perindopril treatment can prevent SERCA mRNA loss in heart but not in diaphragm.

Angiotensin-Converting Enzyme Inhibitors↗

Effects of early and late therapy with perindopril on survival and myocardial inotropic state in experimental dilated cardiomyopathy.

We wished to test (a) whether single-drug therapy with a low dose of the angiotensin-converting enzyme (ACE) inhibitor perindopril has the capacity to improve early survival of the cardiomyopathic Syrian hamster (CSH); (b) whether early treatment with perindopril modifies CSH survival to a greater extent than perindopril treatment initiated later in the course of the disease; and (c) the effects of early and late perindopril therapy on the intrinsic contractility of left ventricular (LV) papillary muscle. We studied CSH from the Bio 53.58 dilated strain (n = 76), in which myocardial necrosis is known to develop from age 30 days, whereas congestive heart failure (CHF) is observed only after age 6 months. Animals were randomly assigned to three groups. In early-treated animals, perindopril (1 mg/kg body weight once daily in distilled water) was administered by force-feeding from age 1 month to 9 months (PE1, n = 21). Animals receiving delayed treatment received distilled water from age 1 month to 6 months, followed by 1 mg/kg body weight from age 6 to 9 months (PE2, n = 34). Controls received distilled water from age 1 month to 9 months (C, n = 21). At endpoint (9 months), mechanical properties of LV papillary muscles and serum ACE activity were studied in a subgroup of 32 CSH (C, n = 8; PE1, n = 10; and PE2, n = 14). Maximum unloaded shortening velocity, maximum extent of systolic shortening in twitch with preload only, and normalized peak of isometric active force were measured.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiotensin-Converting Enzyme Inhibitors↗

Effect of chronic ANG I-converting enzyme inhibition on aging processes. I. Kidney structure and function.

The effect of angiotensin I-converting enzyme inhibition (ACEI) on the age-related changes in the kidney structure and function was investigated in rodents. Normotensive male Wistar (WAG)/Rij rats were treated with perindopril from the age of 6 mo to the day of killing at 12, 24, or 30 mo. Mean blood pressure, constant from 6 to 30 mo, was reduced by 19 mmHg in treated animals. With age, the major functional modifications were a decrease in glomerular filtration rate and in renal blood flow, a rise in intrarenal vascular resistance (IVR), a reduced tubular reabsorption of salts, and a progressive increase in proteinuria. ACEI significantly reduced IVR and proteinuria. From a structural point of view, the glomeruli showed 1) an increase in size, 2) a decrease in capillary surface, 3) a diffuse thickening of the glomerular basement membrane, 4) an expansion of the mesangial matrix, and 5) an accumulation of albumin droplets in podocytes inducing 6) a dispersed focal and segmental glomerulosclerosis which, at 30 mo, affected < 2% of glomeruli. Of these six age-related structural changes, ACEI delayed the appearance of the three latter changes.

Aging↗

Effect of chronic ANG I-converting enzyme inhibition on aging processes. II. Large arteries.

The consequences of hypertension and aging on cardiovascular structure and function are reputed to be similar, suggesting that blood pressure plays a role in the aging process. However, the exact relationship between aging, blood pressure, and the arterial structure-function relationship has not been demonstrated. To test the effects of aging, renin-angiotensin system, and pressure on the arterial wall, 20 normotensive male WAG/Rij rats were killed at 6, 12, 24, and 30 mo of age and compared with similar groups treated with an angiotensin (ANG)-converting enzyme inhibitor (ACEI), perindopril. Arterial function was determined by a systemic hemodynamic study and by in situ measurement of carotid compliance. Arterial wall structure was determined by histomorphometric and biochemical methods. Aging did not significantly modify blood pressure, but ACE inhibition decreased blood pressure significantly from 6 to 30 mo. Plasma renin activity decreased with age and increased with ACEI. Plasma atrial natriuretic factor increased with age and was significantly decreased with ACEI. Absolute and relative left ventricular weight increased with age, and ACEI delayed these increases. Arterial wall stiffness increased with age, as shown by a significant decrease in systemic and local arterial compliance and by an increase in aortic characteristic impedance. The increase in carotid wall compliance after poisoning of smooth muscle contractile function (KCN) was greater in young (6- and 12-mo old) than in old (24- and 30-mo old) rats. Chronic ACEI treatment increased basal carotid compliance values slightly and did not change KCN carotid compliance. The aortic and carotid luminal size increased regularly with age. Aging was associated without any change in absolute elastin content. In contrast, collagen content increased with aging. Aging was also associated with an increase in medial thickness. Medial thickening was mainly due to smooth muscle hypertrophy. Aging was associated with intimal proliferation, which became progressively thicker and collagen rich. ACEI treatment did not prevent aortic lumen enlargement but significantly postponed the increase in medial and intimal thickening. Biochemical determinations of the aortic wall components confirmed the morphometric data. In conclusion, the age-dependent large artery enlargement and stiffening were observed both in normotensive rats and in those rats whose blood pressure was lowered by ACEI. This suggests that aging and blood pressure affect arterial wall structure and function by different mechanisms.

Aging↗

Long-term effects of angiotensin-converting enzyme inhibition on the arterial wall of adult spontaneously hypertensive rats.

The effects of long-term angiotensin-converting enzyme (ACE) inhibitor treatment with perindopril 2 mg/kg/day, by gavage, for 3 months on the mechanical function and structure of large arteries were studied in adult spontaneously hypertensive rats with established hypertension. Hemodynamic parameters, including instantaneous aortic blood flow and pressure, were recorded under anesthesia at the end of the treatment period. Systemic arterial compliance was calculated from aortic pressure and flow recordings; passive mechanical properties of the in situ localized carotid artery were measured. Histologic and morphologic parameters of the aortic media, including cross-sectional area and thickness, size, and density of smooth muscle nuclei and of elastin and collagen fibers, were measured using an automated image analysis system. ACE inhibitor treatment significantly decreased mean arterial pressure (-27%, p < 0.001) and total peripheral resistance (-30%, p < 0.05) while cardiac output was increased (29%, p < 0.05). Systemic arterial compliance and carotid compliance were both increased by treatment (63%, p < 0.05, and 83%, p < 0.05, respectively). Morphometric assessment of vascular structure showed that ACE inhibitor treatment significantly decreased medial cross-sectional area (-36%, p < 0.001) and thickness (-16%, p < 0.001) by affecting smooth muscle cell hypertrophy (nucleus size decreased by 26%, p < 0.05) without changes in smooth cell number. Collagen density was decreased by treatment (-42%, p < 0.05), whereas elastin density was not affected by treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiotensin-Converting Enzyme Inhibitors↗

Effects of angiotensin-converting enzyme inhibition with perindopril on hemodynamics, arterial structure, and wall rheology in the hindquarters of atherosclerotic mini-pigs.

The effects of ACE inhibition with perindopril on the atherosclerosis-induced impairment of arterial flow were investigated via histopathologic studies, hemodynamics, and vascular rheology of hindlimb arteries in 7 adult Pitman-Moore mini-pigs (7 months of age) fed for 4 months with an atherogenic diet and perindopril (at the daily oral dose of 4 mg, which induced a continuous 70% inhibition of serum ACE activity), versus 7 atherogenic and 7 control animals. Major fibroproliferative fatty lesions with medial intimalization were observed in the abdominal aorta. Atherosclerosis impaired the function of both capacitance and resistance hindlimb arteries. In atherogenic mini-pigs, blood pressure (BP) increased significantly due to increased hindlimb peripheral resistance (HPR) and aortic input impedance, although aortic blood flow was not affected. Altered aortic wall rheology revealed that the stiffness of the aorta was markedly increased due to increased wall tension and reduced viscoelasticity, the viscous component being reduced in the arterial wall. Perindopril significantly opposed these alterations by reducing BP, HPR and input impedance and by returning parietal stiffness to control values by increasing aortic compliance. Angiotensin converting enzyme (ACE) inhibition significantly prevented the development of atherosclerosis in the abdominal aorta by decreasing the cross-sectional area of lesions and the presence of lipid-laden cells, as well as by preventing alteration and fragmentation of elastic laminae. In conclusion, ACE inhibition with perindopril showed a significant preventive action on atherosclerosis-induced deleterious effects on vascular wall function and structure in mini-pig arteries.

Angiotensin-Converting Enzyme Inhibitors↗

Myocardial effects of early therapy with perindopril during experimental cardiomyopathy.

The effects of chronic angiotensin-converting enzyme (ACE) inhibition on intrinsic myocardial contractility of the failing myocardium have been poorly documented. In the present study, inotropy, lusitropy, and economy of force generation were studied in vitro in papillary muscles from cardiomyopathic Syrian hamster (CSH) under early perindopril therapy, i.e., therapy begun at a stage when experimental heart failure was not yet observed. One-month-old CSH from the dilated strain Bio 53.58 were randomly treated over a 5-month period with either the ACE inhibitor perindopril 1 mg/kg/day (n = 11) or placebo (n = 11), and 7 age-matched controls were given placebo. Compared with control, placebo had a lower maximum shortening velocity (Vmax) (p < 0.01) and normalized total force (p < 0.05), and a lower curvature of the force-velocity relationship (p < 0.01). It has been shown that the higher the value of the curvature, the better the myothermal economy of force generation. Compared with placebo, perindopril had a 68% inhibition of plasma ACE activity and a greater Vmax (p < 0.05), whereas total force/mm2 was similar. This resulted in a lesser decrease of the curvature compared to control (p < 0.05). Placebo had a decreased peak lengthening velocity and rate of force decline. However, compared to control, no intrinsic abnormalities of the relaxation phase were observed in either placebo or perindopril when relaxation parameters were corrected for the lower systolic performance.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiotensin-Converting Enzyme Inhibitors↗

Intrinsic alterations of diaphragm muscle in experimental cardiomyopathy.

Diaphragmatic function was investigated in the cardiomyopathic Syrian hamster (CSH) from the dilated Bio 53:58 strain, after long-term therapy with the angiotensin-converting enzyme inhibitor perindopril. Twenty-two 1-month old CSHs were treated during a 5-month period by either oral gavage with perindopril (1 mg/kg/day) (n = 11) or placebo (n = 11). Control hamsters from the F1B strain received placebo (n = 7). Mechanical properties were studied in isolated diaphragm strips electrically stimulated in both twitch and tetanic conditions. Compared with F1B control hamsters, peak active tension and positive (+dP/dtmax) and negative (-dP/dtmax) peaks of isometric tension derivative were significantly depressed in placebo treated CSHs. Compared with placebo-treated CSHs, peak active tension was significantly higher in perindopril-treated CSHs in both twitch (25 +/- 4 vs 16 +/- 1 mN/mm2; p < 0.01) and tetanus modes (56 +/- 4 vs 38 +/- 2 mN/mm2; p < 0.01). Moreover, +dP/dtmax and -dP/dtmax were improved significantly in twitch (p < 0.01 and p < 0.01, respectively) and tetanus modes (p < 0.05 and p < 0.01, respectively). We conclude that, in the CSH, long-term therapy with the angiotensin-converting enzyme inhibitor perindopril helped to preserve the diaphragmatic function.

Acetylcholinesterase↗

ACE inhibition with perindopril and atherogenesis-induced structural and functional changes in minipig arteries.

The effects of angiotensin-converting-enzyme (ACE) inhibition on atherosclerosis-induced changes in arterial function are unknown, as well as whether they are coupled to improvements of structural alterations in the arterial wall. An atherogenic (A) diet and the ACE inhibitor perindopril (P) were given concomitantly for 4 months to seven adult Pitman-Moore minipigs (7 months of age; A+P animals), which were compared with seven A and seven control (C) animals. Perindopril, at a daily dose of 4 mg PO that is commonly used in the clinical setting, induced a continuous 70% inhibition of serum ACE activity. At the end of the study, the atherosclerosis-induced impairment of arterial flow was investigated via the hemodynamics and vascular rheology of hindlimb arteries in non-barbiturate-anesthetized pigs. Structural alterations were evaluated from the histopathology of lesions in the arterial tree (abdominal aorta, left interventricular coronary artery [LIVCA], and brachiocephalic trunk [BCT]), with particular attention given to the analysis of the structure and composition of aortic elastic fibers. Atherosclerosis impaired the function of both capacitance and resistance arteries. Blood pressure (BP) rose significantly because of increased hindlimb peripheral resistance (HPR) and aortic input impedance (Zc), although blood flow was not affected. Altered aortic stress and elastic responses revealed that the stiffness of the aorta was markedly increased because of increased wall tension and reduced viscoelasticity, the viscous component being blunted in the arterial wall. Perindopril significantly opposed these alterations by reducing BP, HPR, and Zc and by returning parietal stiffness values to C values by increasing aortic compliance. ACE inhibition prevented the alteration of both stress and elastic responses. Major fibroproliferative fatty lesions were observed in the aorta and LIVCA, while moderate fibrosclerotic lesions were found in the BCT. Computerized densitometric analysis of orcein-stained elastin showed that elastic laminae fragmentation was prominent in the abdominal aorta, less in the LIVCA, and moderate in the BCT. Furthermore, the elastin content was reduced in the atherosclerotic aorta, although this loss of elastin was not associated with changes in the biochemical nature of alkali-insoluble elastin. Perindopril significantly prevented the development of atherosclerosis in the abdominal aorta, LIVCA, and BCT by decreasing the cross-sectional area of lesions as well as the number of lipid-laden cells in the abdominal aorta and LIVCA. In the abdominal aorta, ACE inhibition significantly prevented the alteration of elastic laminae by specifically preventing elastolytic fragmentation of dense elastic laminae, but it didn ot modify elastin content.(ABSTRACT TRUNCATED AT 400 WORDS)

Angiotensin-Converting Enzyme Inhibitors↗

[Protective effects of perindopril in an experimental model of cardiomyopathy].

The effects of an angiotensin converting enzyme (ACE) inhibitor on the intrinsic contractility of the myocardium in cardiac failure have not been studied intensively. The authors studied inotropism, lusitropism and economy of contraction in vitro on left ventricular papillary muscle preparations of cardiomyopathic Syrian hamsters (CSH) treated preventively with perindropil, i.e. before overt signs of cardiac failure. The CSH of the dilated Bio 53.58 strain aged 1 month were treated with perindropil 1 mg/Kg/day for 5 months (PE, N = 11) or with placebo (PL, N = 11) and control hamsters of the F1B strain received placebo (C, N = 7). Compared with C, PL had a significant reduction of the maximal velocity of contraction Vmax (p < 0.01) and of total isometric tension (TF/mm2), p < 0.05, and a reduction of the G curve of the hyperbolic Hill Force-Velocity relationship (p < 0.01). The G value is usually greater in models with improved economy of contraction. When compared with PL, PE showed a 68% inhibition of the plasma activity of ACE, a better Vmax (p < 0.05) but an unchanged TF/mm2. The G value was less depressed than that of C (p < 0.05). The velocity of isotonic relaxation (maxVL) and the negative peak of the derivative of the isometric force (-dF/dt max) were significantly lower in the PL than in the C group but these lusitropic abnormalities remained coordinated with those of the contraction phase, indicating the absence of an intrinsic effect on relaxation in cardiomyopathy. Perindopril prevented the reduction of maxVL but not that of -dF/dt max.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiotensin-Converting Enzyme Inhibitors↗

Effects of perindopril on myocardial inotropy, lusitropy and economy, and on diaphragmatic contractility in the cardiomyopathic Syrian hamster.

Over a 5-month period, 22 1-month-old cardiomyopathic Syrian hamsters were randomly treated with either angiotensin-converting enzyme inhibitor (perindopril 1 mg/kg/day) (PE, n = 11) or placebo (PL, n = 11), and 7 age-matched controls (C) were given placebo. Compared to C, mechanics of left ventricular papillary muscles from PL exhibited a lower maximum unloaded shortening velocity (Vmax) (P less than .01) and normalized peak active force (P less than .05), and a significantly less curved shape of the force-velocity (F-V) relationship (P less than .01). The curvature of the F-V relationship has been proposed as a reflection of the efficiency of muscle contraction. Compared to PL, PE had a 68% inhibition of plasma ACE activity and a greater Vmax (P less than .05), whereas active force (AF) was similar. This resulted in a lesser decrease of the curvature of the F-V relationship compared to that of C (P less than .05). Muscle strips from the ventral costal diaphragm were dissected from the muscle in situ. In both twitch and tetanus modes, intrinsic mechanical performance of diaphragm muscle was markedly decreased in PL compared to C as regards normalized positive (+dF/dtmax/mm2) and negative (-dF/dtmax/mm2) peak rate of force, and normalized peak active force (AF/mm2) (P less than .01 each). In both twitch and tetanus modes, PE had an increased +dF/dtmax/mm2 (P less than .05), -dF/dtmax/mm2 and AF/mm2 (P less than .01 each), compared to PL. These results indicate 1) that the low inotropic state observed in cardiomyopathic Syrian hamsters was associated with decreased myothermal economy of cardiac contraction and with a major impairment of diaphragm intrinsic contractility, and 2) that early therapy with angiotensin-converting enzyme inhibitor helped to preserve myocardial contractility and economy, and diaphragm contractility.

Angiotensin-Converting Enzyme Inhibitors↗

Interaction between an angiotensin converting enzyme inhibitor, perindopril, and a thiazide diuretic in the spontaneously hypertensive rat.

Fifty adult male spontaneously hypertensive rats were randomly allocated to receive daily oral treatment with placebo, hydrochlorothiazide (HCTZ 10 mg/kg) and three different dosages of perindopril (S9490-30.1, 0.3 and 1 mg/kg) administered alone or in combination with HCTZ for two eight-day treatment periods separated by a therapeutic washout period of 13 days. Effect of order of treatment was evaluated in rats receiving perindopril plus HCTZ. Time course of changes in systolic blood pressure, heart rate, 24 h urine volume and urinary excretion of sodium, potassium and chloride were studied and compared for all groups. HCTZ alone and lower dosages of perindopril (0.1 mg/kg, 0.3 mg/kg) were ineffective in lowering elevated systolic blood pressure of the spontaneously hypertensive rat, and there were no significant intergroup differences in urine volume and electrolytes. However, antihypertensive efficacy of lower dosages of perindopril was significantly (P less than 0.01) enhanced when administered in combination with HCTZ. The combined treatment also induced significant (P less than 0.01) diuresis and urinary chloride excretion. No significant effect was seen in heart rate. The dose-effect relationship of the combination confirmed the existence of synergistic antihypertensive action between HCTZ and perindopril in the spontaneously hypertensive rat.

Angiotensin-Converting Enzyme Inhibitors↗

Lack of effect of perindopril on plasma and adrenal corticosteroids in the guinea pig during the estrous cycle and under contraceptive treatment.

We studied changes in cortisol, aldosterone, progesterone, estrogens and cholesterol in cyclic female guinea-pigs and in animals under contraceptive, treated or not with an inhibitor of angiotensin converting enzyme (ACE): perindopril. Perindopril decreased ACE by 80% without affecting steroid profiles. Peak value for plasma progesterone occurred at meta-estrus and diestrus. It disappeared under contraceptive treatment. The very low levels of estrogens in the female guinea pig remained unchanged in all cases. Plasma cortisol concentrations were higher at pro-estrus and estrus whereas plasma aldosterone concentrations remained constant during the estrous cycle and under contraceptive treatment. Furthermore, aldosterone did not change under perindopril treatment despite the decrease of the activity of ACE. The contraceptive treatment decreased plasma cholesterol levels. Under perindopril treatment, this drop was amplified. No change was detected in adrenal steroid concentrations, except for progesterone which decreased under contraceptive treatment.

Adrenal Cortex Hormones↗

Vascular effects of perindopril: from experimental to clinical investigation.

Vascular remodeling is central to the pathophysiology of hypertension and atherosclerosis. The effects of antihypertensive drugs on this process are important to consider from a mechanistic and a pathogenetic point of view in relation to vascular complications of hypertension, e.g., decrease in vascular reserves, shift in cerebral blood flow autoregulation and atherosclerosis development. There is now evidence that, in addition to several other growth factors, vasoactive peptides such as angiotensin II may act as vascular smooth muscle growth promoting substances. Based on these data, the effects of perindopril, a potent and long-lasting angiotensin-converting enzyme (ACE) inhibitor, on structural and mechanical properties of the arterial wall, have been studied in animal models of hypertension as well as in humans. Perindopril completely reversed aortic medial hypertrophy and arterial stiffening observed in renovascular hypertensive rats. Similar benefits were reported in mesenteric resistance vessels of spontaneously hypertensive rats. The effect of perindopril was totally in keeping with potent inhibition of vascular ACE and emphasized the potential role of angiotensin II as a vascular growth modulator. Clinical studies confirmed animal experiments; both suggest that increases in arterial compliance and distensibility following perindopril is likely to be related to drug-induced modification of the arterial wall, at least partially independently of blood pressure reduction. The increase in arterial compliance was associated with a selective decrease in pulse pressure, a finding that is important, not only for the arterial wall, but also for the structure and function of the hypertensive heart.

Angiotensin-Converting Enzyme Inhibitors↗

[Cardiomyopathy in the Syrian hamster. Physiological and therapeutic aspects].

The primary hereditary cardiomyopathy of the Syrian hamster is a particularly interesting model of experimental cardiomyopathy 1) because of its slow progression to cardiac failure unlike acute experimental volume and pressure overloading; 2) because of the reproducibility and predictable nature of the mechanical, biochemical and electrophysiological abnormalities observed at each stage of the disease; 3) because of involvement of other muscle groups, and particularly, skeletal muscle. The physiopathology is not fully understood but a disturbance of intracellular calcium homeostasis appears to play a major role. From the therapeutic point of view, a number of calcium antagonists have been shown to be effective in restoring myocardial function, but they have no effect on skeletal muscular lesions. Recently, early prophylactic intervention with therapeutic doses of perindopril has been shown to prevent the decrease of certain parameters of myocardial contractility in vitro in the dilated group, before the appearance of any signs of cardiac failure. This study also showed that angiotensin converting enzyme inhibitors had no intrinsic negative inotropic effects.

Angiotensin-Converting Enzyme Inhibitors↗