401
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Safar M, Laurent S, Safavian A, Pannier B, Asmar R. Sodium and large arteries in hypertension. Effects of indapamide. Am J Med 1988; 84:15-9. [PMID: 3277415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Epidemiologic studies evaluating arterial pulse wave velocity together with blood pressure indicate that: (1) salt intake has an independent effect on arteriolar tone and arterial wall properties, with the former indirectly and the latter directly contributing to increased arterial stiffness with age; and (2) normotensive adult subjects who follow a low sodium diet have reduced arterial stiffness and this effect is independent of blood pressure. Conversely, in elderly persons with isolated systolic hypertension, isotonic saline infusion causes a predominant increase in systolic pressure due to an increase in the stiffness of the arterial wall. The diuretic indapamide produces a decrease in blood pressure without significant change in brachial artery diameter. The result indicates a shift of the pressure-diameter curve, reflecting for the first time in humans a pharmacologic effect of the drug on arterial vessel. Furthermore, diuretic drugs may increase arterial distensibility and compliance in hypertensive patients, but this effect seems to be more pronounced in older than in younger subjects. In the latter, either activation of the sympathetic nervous system or potassium depletion, or both, might counteract the improvement in arterial distensibility caused by blood pressure reduction and sodium depletion. Based on epidemiologic, clinical, and pharmacologic studies, this critical review suggests that, in patients with essential hypertension, changes of sodium intake in diet or administration of diuretics, or both, affect the status of large arteries independently of blood pressure changes.
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402
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Brisac AM, Champéroux P, Lucet B, Laurent S, Schmitt H. Central and peripheral hypotensive effects of the optical isomers of nicardipine, a dihydropyridine calcium channel antagonist, in rats. Eur J Pharmacol 1988; 146:171-4. [PMID: 3350056 DOI: 10.1016/0014-2999(88)90499-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Central and peripheral hypotensive effects of (+)- and (-)-nicardipine (1-10 micrograms/kg i.v. or i.c.v.) were investigated in normotensive and SH rats. The results suggest that a stereoselectivity exists for the peripheral and central hypotensive effects of the nicardipine isomers. (+)-Nicardipine was shown to be 3-8 times as potent as the (-) isomer in reducing blood pressure in all the experiments.
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403
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Brisac AM, Huguet F, Champeroux P, Montastruc JL, Lucet B, Gerard P, Laurent S, Narcisse G, Schmitt H. Central interactions between dihydropyridines and cholinergic systems in the control of blood pressure in rat. Brain Res 1987; 435:160-6. [PMID: 2448012 DOI: 10.1016/0006-8993(87)91597-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Intracerebroventricular (i.c.v.) injection of the 1,4-dihydropyridine (DHP) calcium channel agonist, Bay K8644 (30 micrograms/kg) increased mean blood pressure and the K+-evoked release of [3H]acetylcholine ([3H]ACh) from hippocampal slices in spontaneously hypertensive rats (SHR). The Bay K8644-induced hypertension was inhibited by a pretreatment with methylatropine (80 micrograms/kg i.c.v.). In SHR, nicardipine, a DHP calcium channel antagonist, reduced mean blood pressure when i.c.v. injected (10 micrograms/kg). The nicardipine-induced hypotension was reduced by a pretreatment with hemicholinium-3 (20 micrograms, i.c.v.). Nicardipine (1 microM) did not modify, in SHR, the K+-evoked release of [3H]ACh, but inhibited the Bay K8644-induced increase in the ACh release. In normotensive rats, neither Bay K8644 nor nicardipine modify blood pressure, when centrally injected, or the stimulated release of [3H]ACh from hippocampal slices. The participation of central DHP sites in the cholinergic transmission in genetic hypertension is discussed.
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404
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Girerd X, Brunel P, Laurent S, Pannier B, Safar M. [Current treatment regimen in essential arterial hypertension]. Presse Med 1987; 16:1689-94. [PMID: 2959944] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The introduction in the treatment of arterial hypertension of angiotensin-converting enzyme inhibitors and calcium inhibitors, as well as the results of extensive multicentric therapeutic trials, suggest that the prescription of antihypertensive drugs will be profoundly altered in the forthcoming years. The "step by step" approach will be abandoned, and each patient will receive one or two drugs chosen for being the most selective and most suitable for his case. These more personalized long-term treatments will be better tolerated, and the greater patient's compliance will make them more effective drugs to the underlying pathology (smoking habits, blood lipid disorders, early arterial lesions) the antihypertensive treatment will have a greater reducing effect on cardiovascular morbidity and mortality.
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405
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Safar ME, Laurent S, Pannier BM, London GM. Structural and functional modifications of peripheral large arteries in hypertensive patients. JOURNAL OF CLINICAL HYPERTENSION 1987; 3:360-7. [PMID: 2889808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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406
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Pannier B, Asmar R, Laurent S, London G, Safar M. [Index of arterial and venous compliance and echocardiographic parameters in essential permanent arterial hypertension]. ARCHIVES DES MALADIES DU COEUR ET DES VAISSEAUX 1987; 80:879-82. [PMID: 2959233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Forearm venous tone (FVT), carotido-femoral pulse wave velocity (PWV), and left ventricular end diastolic diameter (LVD), left ventricular posterior wall thickness (LVPWT), myocardiac mass (MM), measured by echography were evaluated on 25 subjects with sustained essential hypertension and 30 normotensive subjects with same age and same sex. For the overall population, FVT is positively correlated with LVD (r = 0.45, p less than 0.001), with LVPWT (r = 0.37, p less than 0.01) and with MM (r = 0.55, p less than 0.001). PWV is not correlated with LVD but is positively correlated with LVPWT (r = 0.48, p less than 0.001) and with MM (r = 0.40, p less than 0.01). Stroke volume is positively correlated with FVT (r = 0.42, p less than 0.01), but not with PWV. This study shows that in a population of normals and sustained essential hypertensive subjects: i) indexes of venous compliance are correlated with myocardial thickness, myocardiac mass, left ventricular diameter and stroke volume, while ii) indexes of arterial compliance are only correlated with myocardial thickness. Thus, the modifications of arterial and venous compliance observed in sustained essential hypertension influence cardiac structure and function.
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407
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Safar ME, London GM, Bouthier JA, Levenson JA, Laurent S. Brachial artery cross-sectional area and distensibility before and after arteriolar vasodilatation in men with sustained essential hypertension. J Cardiovasc Pharmacol 1987; 9:734-42. [PMID: 2442542 DOI: 10.1097/00005344-198706000-00015] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Blood pressure, volume distensibility (VD), and cross-sectional area (CSA) of the brachial artery were studied using pulsed Doppler systems in 51 patients with sustained essential hypertension in comparison with 21 normotensive controls of the same age. In hypertensive patients, in baseline conditions, CSA was significantly increased and VD decreased--the two parameters strongly and negatively correlated independent of the blood pressure level. Arteriolar vasodilatation was produced by three pharmacological agents--cadralazine, a dihydralazine-like compound; nicorandil, a nicotinamide derivative; and nitrendipine, a calcium entry blocker. For the same blood pressure reduction, cadralazine significantly reduced CSA, while nicorandil and nitrendipine increased it. Nitrendipine significantly increased VD, which was not modified by cadralazine and nicorandil. For cadralazine and nicorandil, a significant negative correlation was observed between VD and CSA. The relationship was the same as in baseline conditions. With nitrendipine, no significant correlation was observed between the two parameters. At any given CSA, distensibility was higher with nitrendipine than with cadralazine or nicorandil. The study provided evidence that, in men with essential hypertension, in basal conditions, the negative relationship between VD and CSA reflected intrinsic alterations of the arterial wall, while cadralazine, nicorandil, and nitrendipine caused a similar degree of arteriolar dilatation, nicorandil and nitrendipine caused active arterial dilatation as well, and changes in distensibility after drug administration were not directly related to blood pressure level and were mediated either by predominant geometrical modifications (cadralazine, nicorandil) or by the predominant relaxing effect of the drug on arterial smooth muscle tone (nitrendipine), or both.
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408
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Labib M, Marks V, Patten J, Barker P, Laurent S, Boulter P. Insulinoma unmasked by the Cambridge diet. BMJ : BRITISH MEDICAL JOURNAL 1987; 294:1383-4. [PMID: 3036293 PMCID: PMC1246551 DOI: 10.1136/bmj.294.6584.1383-a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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409
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Safar ME, Laurent S, Asmar RE, Safavian A, London GM. Systolic hypertension in patients with arteriosclerosis obliterans of the lower limbs. Angiology 1987; 38:287-95. [PMID: 3578917 DOI: 10.1177/000331978703800402] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Intraarterial blood pressure, brachial artery compliance and diameter, and pulse wave velocity were determined in 20 patients with arteriosclerosis obliterans of the lower limbs (AOD) in comparison with 10 age- and sex-matched controls. With the same mean arterial pressure as in controls, patients with AOD exhibited a significant increase in systolic pressure and decrease in diastolic pressure, resulting in an increase in pulse pressure. While brachial artery diameter and pulse wave velocity remained nearly within the normal range, arterial compliance was significantly reduced and was negatively correlated with the level of pulse pressure. The study provided evidence that: atherosclerotic modifications in patients with AOD are associated with an increase in pulse pressure, which predominates on the increase in mean arterial pressure, increased pulse pressure is related to decreased arterial compliance, which reflects intrinsic modifications of the viscoelastic properties of the arterial wall.
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410
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Laurent S, Girerd X, Tsoukaris-Kupfer D, Legrand M, Huchet-Brisac AM, Schmitt H. Opposite central cardiovascular effects of nifedipine and BAY k 8644 in anesthetized rats. Hypertension 1987; 9:132-8. [PMID: 2434422 DOI: 10.1161/01.hyp.9.2.132] [Citation(s) in RCA: 35] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The central cardiovascular effects of the calcium channel blocker nifedipine and the calcium channel activator BAY k 8644 were studied in anesthetized and ventilated normotensive Wistar-Kyoto (WKY) or spontaneously hypertensive rats (SHR). Both drugs were administered in a 1.5-microliter volume into the lateral ventricle of the brain (i.c.v.) or into the cisterna magna (i.c.). The injection of vehicle alone (i.c. or i.c.v.) did not significantly change mean arterial pressure (MAP) or heart rate. Nifedipine (5 and 50 micrograms/kg) and BAY k 8644 (5 and 50 micrograms/kg) induced opposite effects on MAP when centrally injected. Nifedipine decreased MAP and induced a bradycardia (i.c.v.) or no change in heart rate (i.c.), and BAY k 8644 increased MAP without any significant change in heart rate (i.c. or i.c.v.). These effects were more marked with the highest dose of either drug. These effects seemed to be of central origin, since they were suppressed by ganglionic blockade by hexamethonium (100 mg/kg i.v.), whereas after hexamethonium the hypotensive and the hypertensive responses to intravenously injected nifedipine and BAY k 8644, respectively, were preserved. Bilateral vagotomy suppressed the bradycardia induced by i.c.v. administered nifedipine. Previously i.c.v. administered nifedipine (5 micrograms/kg) antagonized the pressor response to BAY k 8644 (5 micrograms/kg i.c.v.). Changes in MAP and heart rate were significantly more marked in SHR than in WKY. These results indicate that a calcium channel inhibitor and a calcium channel activator can modulate in opposite fashion central mechanisms involved in blood pressure control.
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MESH Headings
- 3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester/administration & dosage
- 3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester/pharmacology
- Animals
- Blood Pressure/drug effects
- Cisterna Magna
- Heart Rate/drug effects
- Injections, Intraventricular
- Male
- Nifedipine/administration & dosage
- Nifedipine/pharmacology
- Rats
- Rats, Inbred SHR
- Rats, Inbred WKY
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411
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Asmar RG, Pannier BM, Hugue CJ, Laurent S, Safavian A, Safar ME. Captopril + hydrochlorothiazide 24 h ambulatory monitoring effects. Br J Clin Pharmacol 1987; 23 Suppl 1:77S-81S. [PMID: 3555586 PMCID: PMC1386049 DOI: 10.1111/j.1365-2125.1987.tb03125.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
The purpose of this study was to evaluate over a 24 h period the antihypertensive effect of captopril 50 mg + hydrochlorothiazide (HCTZ) 25 mg once a day in mild to moderate hypertension. Ambulatory recordings over 24 h of the blood pressure using the Spacelabs system were performed, at the end of a 15-day placebo period and after giving captopril + HCTZ for 45 days. Captopril + HCTZ significantly decreased (P less than 0.001) systolic and diastolic blood pressures for both the diurnal period (8 h to 22 h) and the nocturnal period (22 h to 8 h). No change in heart rate was observed. For further analysis, the mean hour values of blood pressure and heart rate were calculated. A constant decrease of the systolic and diastolic blood pressure throughout the 24 h was obtained after captopril + HCTZ without any change in heart rate and in nyctohemeral variations. The study provided evidence that, in patients with mild to moderate essential hypertension, captopril + HCTZ once a day decreased systolic and diastolic blood pressure all day long without any change in the heart rate and the blood pressure nyctohemeral cycle.
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412
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Safar ME, Laurent S, Bouthier JA, London GM. Comparative effects of captopril and isosorbide dinitrate on the arterial wall of hypertensive human brachial arteries. J Cardiovasc Pharmacol 1986; 8:1257-61. [PMID: 2434755 DOI: 10.1097/00005344-198611000-00024] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Blood pressure, diameter, volume distensibility, and compliance of brachial artery were measured noninvasively in patients with sustained essential hypertension before and after Captopril in 11 patients and before and after isosorbide dinitrate (ISDN) in 11 other patients. Both drugs caused a similar significant decrease in mean arterial pressure (MAP) (p less than 0.001) and increase in arterial compliance (p less than 0.001), defined as the product of arterial volume by distensibility. ISDN increased arterial compliance through a dominant increase in arterial diameter (0.524 +/- 0.029 vs. 0.455 +/- 0.022 cm; p less than 0.001) and hence volume, whereas Captopril increased compliance through an increase in volume distensibility (0.20 +/- 0.02 vs. 0.12 +/- 0.02% change volume/mm Hg; p less than 0.001) with minimal changes in arterial diameter. The study provided evidence that of the two vasodilating drugs, ISDN and Captopril, only Captopril caused a predominant pharmacological relaxing effect on the wall of hypertensive human brachial arteries studied in situ.
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413
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Laurent S, London G, Safar M. [Non-invasive study of the role of carotid distension in the baroreflex response to the arteriolar vasodilator cadralazine in essential hypertension]. ARCHIVES DES MALADIES DU COEUR ET DES VAISSEAUX 1986; 79:937-41. [PMID: 3099714] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Using pulsed Doppler methods, hemodynamics of the common carotid and the brachial arteries were measured in 10 patients with essential hypertension. After vasodilatation due to Cadralazine, a Dihydralazine-like substance, mean arterial pressure significantly decreased and heart rate increased. Change in PRA was significantly and positively correlated with the change in heart rate. In the brachial artery circulation, diameter and vascular resistance decreased while blood flow velocity and volumic blood flow did not increase significantly. In the common carotid artery circulation, diameter, mean blood flow did not change. However, vascular resistance and tangential tension decreased slightly. The increase in heart rate was strongly and negatively correlated (r = 0.82 p less than 0.01) with the change in the carotid artery tangential tension (measured as the product between mean arterial pressure and arterial radius) while no comparable correlation was observed with the change in blood pressure or arterial radius alone. The study suggested that in essential hypertensives, modifications in the carotid artery tangential tension secondary to arteriolar vasodilatation contribute actively to the baroreflex response.
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414
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Girerd X, Laurent S, Tsoukaris-Kupfer D, Schmitt H. [Central cardiovascular effects of a calcium inhibitor, nifedipine, and a calcium channel activator, Bay k 8644, in the anesthetized rat]. ARCHIVES DES MALADIES DU COEUR ET DES VAISSEAUX 1986; 79:923-8. [PMID: 2432847] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The antihypertensive effect of calcium channel inhibitors (CCI) results mainly from their direct action on the vascular smooth muscle. However CCI may pass through the blood-brain barrier and may modulate central mechanisms involving calcium channels. Normotensive (WKY) and spontaneously hypertensive (SHR) (Okamoto) rats weighing 300 g were anaesthetized with pentobarbital (50 mg/kg i.p.) and ventilated. Mean arterial pressure (MAP) was measured from a catheter inserted into the femoral artery. Heart rate (HR) was electronically integrated. Vehicle (ethanol 95%), nifedipine and Bay k 8644 (Bay) were injected under a 1.5 microliter volume into the lateral ventricle of the brain (i.c.v.). Vehicle alone did not change significantly MAP or HR. The calcium-channel inhibitor nifedipine and the calcium-channel activator Bay had opposite effects, when i.c.v. injected: hypotension with bradycardia and hypertension without tachycardia, respectively. These effects are dose-dependent (5-50 micrograms/kg). They are of central origin since they are suppressed by ganglionic blockade by hexamethonium(100 mg/kg i.c.). Bilateral vagotomy suppressed the i.c.v.-nifedipine induced bradycardia. Previously i.c.v. administered nifedipine (5 micrograms/kg) suppressed the pressor response to Bay (5 micrograms/kg i.c.v.). Changes in MAP and HR are significantly more marked in SHR than in WKY. These results indicate that a calcium-channel inhibitor and a calcium-channel activator can modulate in opposite fashion central calcium-dependent mechanisms involved in blood pressure control.
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415
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Laurent S, Marsh JD, Smith TW. Enkephalins increase cyclic adenosine monophosphate content, calcium uptake, and contractile state in cultured chick embryo heart cells. J Clin Invest 1986; 77:1436-40. [PMID: 2422207 PMCID: PMC424543 DOI: 10.1172/jci112455] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Peripheral vascular effects of opioid peptides are well known, but direct myocardial effects have not been established. We studied the inotropic response of spontaneously beating cultured chick embryo ventricular cells to the enkephalin analogue [D-Ala2]-enkephalin. Amplitude of cell motion increased in a concentration-dependent manner with 0.53 microM [D-Ala2]-enkephalin producing half-maximal response. The mechanism of this positive inotropic effect was investigated by examining alterations in 45Ca influx, cyclic AMP accumulation and adenylate cyclase activity in response to [D-Ala2]-enkephalin. At maximally inotropic concentrations, the 45Ca influx rate increased 39%, adenylate cyclase was stimulated by 30%, and cyclic AMP content rose more than twofold. Thus, in contrast to neural tissue, receptors for enkephalin in cultured heart cells are coupled to adenylate cyclase in a stimulatory manner. Occupancy of these receptors produces an increase in cyclic AMP levels and exerts a positive inotropic effect via a verapamil-sensitive enhancement of Ca influx.
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416
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Benetos A, Safar ME, Laurent S, Bouthier JD, Lagneau PL, Hugue C. Common carotid blood flow in patients with hypertension and stenosis of the internal carotid artery. JOURNAL OF CLINICAL HYPERTENSION 1986; 2:44-54. [PMID: 3522814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Common carotid blood flow has been measured using pulsed Doppler techniques in hypertensive patients over 45 years of age, with and without stenosis of the internal carotid artery. In hypertensive patients without stenosis, arterial diameter remained within the normal range, whereas blood flow velocity and blood flow were significantly reduced. Vascular resistance was significantly increased but did not change markedly after administration of the vasodilating drug isosorbid dinitrate. Patients with hypertension and stenosis of the internal carotid artery were compared with two different populations used as controls: In comparison with hypertensive patients without stenosis of the internal carotid artery, both arterial diameter and blood flow velocity were reduced, leading to a more pronounced decrease in blood flow; and in comparison with normotensive patients with stenosis of the internal carotid artery, common carotid blood flow was more reduced at any degree of stenosis. In a subset of patients, blood flow returned toward normal ranges after endarterectomy. The study suggested that in patients with hypertension without stenosis of the internal carotid artery, the decrease in blood flow is due to a decrease in blood flow velocity with normal arterial diameter despite the elevated blood pressure, and in patients with hypertension and stenosis of the internal carotid artery, blood flow was more reduced than in the normotensive patients with stenosis of the internal carotid artery, suggesting that caution must be taken with indications of antihypertensive treatment.
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417
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Laurent S, Kim D, Smith TW, Marsh JD. Inotropic effect, binding properties, and calcium flux effects of the calcium channel agonist CGP 28392 in intact cultured embryonic chick ventricular cells. Circ Res 1985; 56:676-82. [PMID: 2581718 DOI: 10.1161/01.res.56.5.676] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
CGP 28392 is a recently described dihydropyridine derivative with positive inotropic properties. To study the mechanism of action of this putative calcium channel agonist, we have related the effects of CGP 28392 on contraction (measured with an optical video system) and radioactive calcium uptake to ligand-binding studies in cultured, spontaneously beating chick embryo ventricular cells. CGP 28392 produced a concentration-dependent increase in amplitude and velocity of contraction (EC50 = 2 X 10(-7) M; maximum contractile effect = 85% of the calcium 3.6 mM response). Nifedipine produced a shift to the right of the concentration-effect curve for CGP 28392 without decreasing the maximum contractile response, suggesting competitive antagonism (pA2 = 8.3). Computer analysis of displacement of [3H]nitrendipine binding to intact heart cells by unlabeled CGP 28392 indicated a KD = 2.2 +/- 0.95 X 10(-7) M, in good agreement with the EC50 for the inotropic effect. CGP 28392 increased the rate of radioactive calcium influx (+39% at 10 seconds) without altering beating rate, while nifedipine decreased radioactive calcium influx and antagonized the CGP 28392-induced increase in calcium influx. Our results indicate that, in intact cultured myocytes, CGP 28392 acts as a calcium channel agonist and competes for the dihydropyridine-binding site of the slow calcium channel. In contrast to calcium channel blockers, CGP 28392 increases calcium influx and enhances the contractile state.
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418
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Laurent S, Schmitt H. Central cardiovascular effects of kappa agonists dynorphin-(1-13) and ethylketocyclazocine in the anaesthetized rat. Eur J Pharmacol 1983; 96:165-9. [PMID: 6319158 DOI: 10.1016/0014-2999(83)90547-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Opiate kappa agonists were administered into the cisterna magna of normotensive urethane-anaesthetized artificially ventilated rats: ethylketocyclazocine (78.7 nM) (EKC) and dynorphin-(1-13) (62.3 nM) produced significant and long-lasting decreases in both blood pressure and heart rate. High doses of naloxone (1 mg/kg i.v.) were required to partially antagonize these effects. The central cardiovascular effects of EKC and dynorphin-(1-13) were compared to those of fentanyl (3 nM), [D-Ala2,Met5]enkephalinamide (17 nM) and beta-endorphin (2.9 nM) which induced increases in blood pressure and heart rate. These results suggest that opposite central cardiovascular effects could be induced by activation of various opiate receptors.
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419
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Gourgon R, Neukirch F, Zygelman M, Michel PL, Mérillon JP, Pansard Y, Squara P, Laurent S, Dahan M, Juliard JM. [Hemodynamic and coronary effects of molsidomine in patients with stable coronary insufficiency in the basal state, during an atrial stimulation test and a cold test]. Ann Cardiol Angeiol (Paris) 1983; 32:529-34. [PMID: 6689395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The heart rate (HR), the cardiac output (Qc) and the coronary sinus flow rate (Qcs), the left ventricular systolic and end-diastolic pressures (LVSP, LVEDP), the femoral artery pressure (FAP) and the difference between the coronary arterial and coronary venous oxygen tension (DAVcO2) were measured in patients with stable coronary insufficiency without cardiac failure, before and 40 to 60 minutes after 2 or 3 mg of molsidomine (M). In 20 patients, these measurements were made in the basal state, in spontaneous rhythm (SP). In 8 of these patient, (including 3 receiving beta-blockers) the measurements were made during an atrial stimulation test (ST) and in 8 other patients, all receiving long-term beta-blocker therapy, the measurements were made during a cold test (CT). At the basal state in SR, a gradual reduction in the LVSP to 70% or less of its initial value was observed in the patients receiving 3 mg of M (2 of whom received beta-blocker treatment). The LVSP was immediately restored by vascular filling. In 16 patients, M decreased the LVSP, the LVEDP, the FAP, the Qc and the double product (DP = LVSP X HR). The DAVcO2 was unchanged. Qcs and MVO2 (MVO2 = Qcs X DAVcO2) were decreased. In the course of ST, the haemodynamic and coronary changes are similar to those seen in the basal state. During the Ct, the increase in the LVSP, FAP and DP was significantly reduced by M. The variations in Qcs and coronary resistance (FAP/Qcs) were also significantly different after M., with better metabolic regulation of the coronary circulation.(ABSTRACT TRUNCATED AT 250 WORDS)
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420
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Laurent S, Schmitt H. Opposite central cardiovascular effects of various morphine-like drugs and opiate peptides in the rat. Eur Heart J 1983; 4 Suppl G:61-5. [PMID: 6363080 DOI: 10.1093/eurheartj/4.suppl_g.61] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Opiate agonists were administered into the cisterna magna of normotensive urethane-anaesthetized artificially-ventilated rats. Increases in blood pressure and heart rate were produced by fentanyl (0.3-3.0 nmol). [D-ala]2-met-enkephalinamide (17 nmol), and beta-endorphin (2.9 nmol). On the contrary, ethylketocyclazocine (78.7 nmol) and dynorphin (1-13) (62.3 nmol) produced decreases in blood pressure and heart rate. The cardiovascular effects of ethylketocyclazocine and dynorphin (1-13) were antagonized by higher doses of naloxone than that required to counteract the effects of fentanyl. These results suggest that opposite central cardiovascular effects could be induced by activation of various opiate receptors.
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421
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Amar C, Vilkas E, Laurent S, Gautray B, Schmitt H. A new enkephalin analogue: trans-4-hydroxycinnamoyl-glycyl-glycyl-phenylalanyl-leucine. Synthesis and biological properties. INTERNATIONAL JOURNAL OF PEPTIDE AND PROTEIN RESEARCH 1983; 22:434-6. [PMID: 6654590 DOI: 10.1111/j.1399-3011.1983.tb02112.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
A new analogue of the leucine-enkephalin in which the N-terminal tyrosine has been replaced by trans-4-hydroxycinnamic acid, has been synthetized by liquid-phase coupling methods. The central cardiovascular effects of this analogue were investigated and the results discussed.
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422
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Simon AC, Laurent S, Levenson JA, Bouthier JE, Safar ME. Estimation of forearm arterial compliance in normal and hypertensive men from simultaneous pressure and flow measurements in the brachial artery, using a pulsed Doppler device and a first-order arterial model during diastole. Cardiovasc Res 1983; 17:331-8. [PMID: 6883408 DOI: 10.1093/cvr/17.6.331] [Citation(s) in RCA: 38] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Simultaneous brachial artery pressure and blood flow measurements were made in 45 men. Blood flow was evaluated by means of a pulsed Doppler device with a double transducer probe. From analysis of the pressure-flow curves during diastole, forearm arterial compliance (FAC) was determined by using the model of the forearm arterial tree as a system of tubes, each with a storage capacitance, in series with the arteriolar resistances vessels. The value of FAC for seven normal subjects, aged 44 +/- 3 (mean +/- SEM) years, was between 0.78 and 1.73 X 10(-10) m5 . N-1. By comparison, a 30% reduction in FAC was observed in 38 men of the same age with essential hypertension, which was similar whether the intra-arterial diastolic pressure was above or below 90 mmHg. In the more severe group (Intra arterial diastolic pressure greater than 90 mmHg), the reduced FAC was associated with a significant increase in brachial artery diameter; after administration of dihydralazine, blood pressure and arterial diameter returned to normal but FAC remained diminished. The study is the first to evaluate FAC in intact men. The reduced FAC in hypertension is independent of blood pressure "per se" but may reflect adaptive change in the walls of the large arteries. In the more severe hypertension, arterial calibre was increased; this could be a mechanism which could prevent FAC from decreasing further with chronic elevation of blood pressure.
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423
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Laurent S, Lagrange JL, Sereni D, Dhainaut JF, Laroche C, Monsallier JF. [Lesional pulmonary edema in miliary tuberculosis]. LA NOUVELLE PRESSE MEDICALE 1981; 10:3318. [PMID: 7301562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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424
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Audebert AA, Laurent S, Tessier F, Gintzburger S, Krulik M, Canuel C, Debray J. [Picture of ankylosing spondylitis in Yersinia enterocolitica septicemia]. Rev Med Interne 1981; 2:305-7. [PMID: 7291784 DOI: 10.1016/s0248-8663(81)80030-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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425
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Laurent S, du Cailar J. [Anesthesia with continuous infusion of alfatesine and phenoperidine. Uses in anesthesia of aged subjects in visceral surgery]. ANNALES DE L'ANESTHESIOLOGIE FRANCAISE 1977; 18:265-72. [PMID: 20004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Anaesthesia was administered to one hundred and fifty eight patients by continuous infusion of a mixture of Alfatesine and phenoperidine. The patients were divided on two groups: group A consisted in 96 patients undergoing abdominal surgery and group B of 62 cases of various types of surgery, mainly orthopedics. The average age was 63 years (range 16-96). The operative risk scored 6 or more in 71 cases. The length of operation averaged 151 minutes (S.D. +/- 15). The mixture made of alfadione 25 ml and phenoperidine 5 mg in a glucose 5 per cent 250 ml solution was administered by mechanical pump. The induction dose was 50 ml of the mixture for patients under 50 years (rate 10 ml per minute), 40 ml per patients from 50 to 70 years (5 ml per minute), and 30 ml for patients over 70 years (5 ml per minute). The maintenance dose was adjusted to weight and age and ranged from 0,11 to 0,15 ml/kg/h for alfadione and from 0,022 to 0,030 mg/kg/h for phenoperidine. Routine tracheal intubation and artificial ventilation were performed in group A. The results are studied in relation to the effectiveness of the anaesthesia mixture, its side effects and influence on recovery. Generally, the results are good and emphasize the value of the technic in abdominal surgery for elderly patients. The methods of application are discussed in terms of medical background.
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426
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Laurent S. [Effect of prolonged glucidic starvation on the contents of starch and tannins of Blechnum brasiliense L. gametophytes]. ARCHIVES INTERNATIONALES DE PHYSIOLOGIE ET DE BIOCHIMIE 1976; 84:819-31. [PMID: 65957 DOI: 10.3109/13813457609067057] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Some Blechnum brasiliense gametophytes have been maintained in darkness, in a purely mineral medium, for the purpose of investigating the effect of prolonged glucidic starving on the amount of tannins and starch that they contain. During the first two months the tannin contents undergoes a fast decrease. The starch variations are different : a transitory increase simultaneous with the fall in tannin; a decrease after the disappearance of 3/4 of the tannin contents; and lastly, a new amylogenese which precedes the prothallus necrosis. It seems that the gametophytes, in order to survive, degrade first their tannoidic reserves, and they utilize the starch that they contain only with difficulty. This behaviour can be explained by the distribution of the two metabolites; by the acid pH of the medium, which is not very propitious to the phosphorylases activity and lastly by the presence of chlorogenic acids, which are inhibitors of those enzymes.
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427
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Laurent S. [Comparative study of different extraction methods and assays of tannins in some pteridophytes]. ARCHIVES INTERNATIONALES DE PHYSIOLOGIE ET DE BIOCHIMIE 1975; 83:735-52. [PMID: 57755 DOI: 10.3109/13813457509081892] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Various processes of extraction and quantitative analysis of a condensed tannin in a plant extract, which also includes some chlorogenic acids, have been examined. 60% methanol, at 50 degrees C, proved the most efficient extraction solvent. Several methods of analysis have been tried. The measure of the colour intensity obtained by the action of sulphuric vanilline on flavanols cannot be used because it depends on the tannin condensation stage. It is impossible to separate tannin from chlorogenic acids using the methods of adsorption by skin or nylon powders, or precipitation by polyvinylpyrrolidone. Only paper chromatography, followed by the distinct elution of the various phenolic compounds, allows the tannin evaluation by subtraction; but owing to the variability of the results, many more experiments are necessary. Some other processes are being studied.
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428
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Kienlen J, Arnefaux J, Brabet L, Dupont MH, Grolleau D, Guilhot R, Laurent S, Sube J, Vernette M, Wintrebert P, du Cailar J. [Anesthesia in reoperations in abdominal surgery]. ANNALES DE L'ANESTHESIOLOGIE FRANCAISE 1975; 16:241-51. [PMID: 2041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Fifty one patients from different surgical units, hence anesthetized by different anaesthesists, underwent reinterventions in abdominal surgery. The indications for the first intervention essentially involved the supra-mesocolic region of the abdomen (62 out of 100 cases). The operative risk during the first intervention was on the average 18 pour cent. The protocol of the first anaesthesia which was known in 42 cases, was of the narco-ataralgestic type. The date of the return to the operation table varied from 1 to 60 days. The state of the patients was in general catastrophic (organic renal failure, acute respiratory failure). Here again the anaesthesia was of the narco-ataralgesic type but the choice of drugs varied depending on the patients' state. However non significant difference was noted in the average hourly drug consumption between the two interventions. Apart from one circulatory arrest during induction, in one patient with hemorrhagic shock, no death was attributable to the anesthetic technique. The authors, using these findings, attempt to pick out a practical line of behaviour.
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429
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Sanna S, Laurent S, Isorni GP, Belioz F. [Prenatal fetal electrocardiogram; comparison of 2 methods of direct recording (in 300 cases)]. ATTI DELLA SOCIETA ITALIANA DI CARDIOLOGIA 1969; 2:98-111. [PMID: 5406557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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430
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Mourgue-Molines E, Laurent JC, Rolet JF, Laurent S, Serre L. [Intracardiac penetration of a brassiere steel in the course of thoracoabdominal bullet transfixing]. ANNALES DE CHIRURGIE 1967; 21:516-20. [PMID: 5618782] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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