ISSN:0263-6352    

出版商:OVID    

年代:1989

数据来源: OVID

ISSN:0263-6352    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

This study tested the hypothesis that a sphygmomanometer cuff bladder long enough to encircle the arm in most adults ('obese cuff) would provide a more accurate and precise estimate of intra-arterial pressure than the usual 'standard ' cuff bladder. In 53 patients undergoing diagnostic coronary angiography (35 males, 18 females, aged 36–79 years), indirect blood pressure, measured in the left arm with a random-zero sphygmomanometer, was compared with simultaneously measured femoral intra-arterial pressure. Duplicate indirect measurements were made with each of two cuffs containing bladders measuring 39 15 cm ('obese') and 23 12 cm ('standard').The obese cuff bladder encircled 80% or more of the arm circumference in all subjects, whereas the standard cuff bladder met this requirement in only 19% of the subjects. For both systolic and diastolic pressure there was marked interindividual variability in the differences between indirect and direct measurements with both cuffs. With the obese cuff there was no systematic error in the diastolic blood pressure measurement. The standard cuff consistently overestimated diastolic pressure by 7.7 ± 8.3mmHg (mean ±s.d.). For both cuffs, the difference between indirect and direct diastolic pressure increased with arm size (P<0.05). Both cuffs underestimated systolic blood pressure, the obese cuff by 15.5 ± 11.7mmHg and the standard cuff by 7.6 ± 12.1 mmHg. These systolic blood pressure underestimates were greater at higher blood pressures (P<0.01) and with smaller arms (P<0.05). Age was not related to measurement error with either cuff.These results have demonstrated the inherent problems with indirect blood pressure measurement by sphygmomanometry, viz. its unreliability and the consistent underestimation of systolic pressure. The obese cuff is more appropriate than the standard cuff for routine adult blood pressure measurements, as it provides a more accurate estimate of diastolic pressure, the accepted criterion for the diagnosis and management of hypertension.

ISSN:0263-6352    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

The renin inhibitor CGP 29287 was administered continuously for 7 days (30mg/kg per day, intraperitoneally, via osmotic minipumps) to normotensive marmosets fed a low-salt diet. As a control, another group of marmosets was given vehicle only. After 7 days of treatment, the mean arterial blood pressure of the CGP29 287-treated marmosets was significantly lowered by about 23mmHg. Plasma immunoreactive total and active renin were increased 10- and sevenfold, respectively, whereas plasma renin activity (PRA) was reduced by 95%. Plasma angiotensin II (Ang II) and aldosterone were also reduced (by 97 and 85%, respectively). Serum angiotensin converting enzyme activity was unchanged and there were no differences in plasma concentrations of electrolytes, urea or creatinine between CGP29 287-treated and control marmosets. These results indicate that although renin release is markedly stimulated after continuous administration of a renin inhibitor for 7 days, the formation of Ang II and aldosterone, the active hormones of the renin-angiotensin system, is substantially reduced.

ISSN:0263-6352    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

The effects of ketanserin on blood pressure and well-being were investigated in 188 patients, aged 41–82 years, with mild to moderate essential hypertension. At entry, 107 were untreated, 42 were taking the diuretic combination hydrochlorothiazide (50mg/day) plus amiloride (5mg/day) and another 39 were taking the ß-blocker atenolol (100mg/day). A single-blind, 4-week placebo run-in period was followed by 12 weeks' oral ketanserin treatment at 20 or 40 mg twice a day. This regimen significantly reduced systolic and diastolic blood pressures in each group. Response rates were greater in patients aged over 60 years. Compared with placebo, sleep disturbances, daytime fatigue and overall weakness decreased during ketanserin treatment (P<0.05 for all), but the incidence of dry mouth and stuffy nose increased. In patients older than 60 years there was a greater reduction of complaints than in younger patients. Ketanserin proved effective and well tolerated, improving peripheral circulatory symptomatology, particularly in older patients and those with a good blood pressure response.

ISSN:0263-6352    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

The mechanism of glucocorticoid-induced hypertension is not known. Although glucocorticoids can exert an inhibitory effect on prostaglandin synthesis invitro, theirin vivoinfluence on this system is controversial. The goal of the present study was to determine whether dexamethasone-induced hypertension in Wistar rats is due to inhibition of the synthesis of the vasodilator prostaglandin l2(PGI2)in vivo.Dexamethasone caused a profound reduction (7 ± 1 versus 21 ± 5ng per 24 h) in the urinary excretion of PGI-M (PGI-M), a major metabolite of PGI2, and a sustained rise in systolic arterial pressure which was maximal after 5 days (144 ± 9 versus 103 ± 3mmHg). A study of the metabolism of [3H]-labeled 6-oxo-PGF1and PGI2revealed that dexamethasone exerted a dual action on the prostaglandin systemin vivo:an inhibition of PGI2biosynthesis and an alteration of its metabolism, both effects contributing to the observed reduction in urinary levels of PGI-M.Exogenous arachidonic acid induced a fourfold increase in urinary PGI-M in normal rats (from 14 ± 3 to 61 ± 6ng per 24 h). Despite a large decrease upon addition of dexamethasone, urinary PGI-M remained in the high-normal range in arachidonic acid-treated rats (21 ± 8 ng per 24 h). Arachidonic acid exerted antihypertensive effects which were marginal initially but significant in the later phase of dexamethasone-induced hypertension (124 ± 8 versus 139 ± 8mmHg in arachidonic acid-treated versus control rats after 7 days of dexamethasone). The antiglucocorticoid agent RU-486 reversed almost entirely the rise in blood pressure but only marginally reduced urinary PGI-M caused by dexamethasone. The non-steroidal anti-inflammatory agent meclofenamic acid reduced urinary PGI-M to the same extent as dexamethasone but did not cause any increase in arterial pressure.In conclusion, dexamethasone exerts a profound influence on both the biosynthesis and the metabolism of PGI2in vivoin Wistar rats. However, the mechanism initiating glucocorticoid hypertension is not dependent upon the inhibition of either PGI2biosynthesis or arachidonic acid metabolism, although such an effect may contribute to the severity of hypertension with time by preventing the moderating influence of vasodilator metabolites of arachidonic acid.

ISSN:0263-6352    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

The acute haemodynamic effect of perindoprilat was examined at rest, supine and sitting, and during 100W bicycle exercise in 12 patients (mean age 42 years) with essential hypertension. Intra-arterial blood pressure and the heart rate were recorded continuously. Cardiac output was measured by dye dilution (Cardiogreen) and blood volume was determined by radio-iodinated (125I) human serum albumin. Two hours after a slow (3min) intravenous injection of perindoprilat, blood pressure was reduced in all patients (P<0.01) — at rest sitting from 175/108 to 153/97 mmHg (11%) — because of reduction in total peripheral resistance index (f=2.63; P<0.05). Only minor changes were seen in the heart rate, stroke index and cardiac output. The fall in blood pressure was significantly (P<0.05) correlated with blood volume (r=0.65) and pretreatment total peripheral resistance index (r=0.59).

ISSN:0263-6352    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

We examined the effects of intracerebroventricular (i.c.v.) administration of atrial natriuretic factor (ANF) on pressor and natriuretic responses induced by i.c.v. angiotensin II (Ang II) or hypertonic NaCI. Conscious male Wistar rats were given one of the following solutions into the lateral ventricle: artificial cerebrospinal fluid (CSF); rat ANF (99–126) 1.0 µg/kg per min; Ang II 100 ng/kg per min; 0.6 mol/l NaCI; Ang II plus ANF, and 0.6 mol/l NaCI plus ANF.The i.c.v. infusion of artificial CSF or ANF alone did not cause significant changes in mean blood pressure, urinary volume or sodium excretion (UNaV). The i.c.v. infusion of Ang II or 0.6 mol/l NaCI raised mean blood pressure, decreased urinary volume and increased UNaV. When ANF was administered with Ang II, the Ang ll-induced responses were diminished significantly (Δmean blood pressure, +10 ± 3 versus + 20 ± 4mmHg; Δurinary volume, - 38 ± 9 versus - 78 ± 5µl/min; ΔUNaV, +0.49 ± 0.51 versus + 2.28 ± 0.58 µmol/min). The centrally administered ANF opposed the effects of 0.6 mol/l NaCI, though the effect was significant only in respect of blood pressure.Our results indicate that the brain ANF may have an antinatriuretic role in some conditions. Journal of Hypertension 1989, 7:639–643

ISSN:0263-6352    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

Two formulations of felodipine, conventional and extended release (ER) tablets, were compared in a double-blind, crossover study of patients whose blood pressure was not being controlled using metoprolol 100 mg once daily. Nineteen patients with a supine diastolic blood pressure ≥ 95 mmHg after 4 weeks of taking metoprolol and placebo were randomly assigned to felodipine conventional (5 mg twice a day) or ER (10 mg once daily) for 4 weeks. A 2-week washout period was then followed by 4 weeks of treatment with the alternative formulation. Metoprolol once daily was taken concomitantly throughout the study. Clinic blood pressure was measured at 0h (i.e. 12h after the last dose of conventional, and 24 h after the last ER felodipine dose), and then 2 and 5 h after the following dose had been taken. Ambulatory blood pressure and the heart rate were monitored over 24 h using an Accutracker (Suntech Medical Instruments, Raleigh, North Carolina, USA). During the final treatment, both felodipine formulations caused similar substantial falls in supine blood pressure compared with pressures prior to randomized treatment. The falls in clinic blood pressures (systolic/diastolic) were similar with the conventional and ER formulations at all time points, i.e. 0 h (21/13; 19/11 mmHg), 2 h (39/18; 36/18mmHg) and 5 h (30/12; 35/11 mmHg) after the morning dose was taken. Both formulations also produced similar falls in blood pressures over 24 h and during the daytime (21/12; 20/12mmHg). The mean overnight (2300–0800 h) blood pressures were slightly but significantly lower (P<0.05) during treatment with conventional (134 ± 20/78 ± 16 mmHg, mean ± s.d.) than with ER tablets (139 ± 20/81 ± 14 mmHg). However, it is unlikely that this difference is of clinical significance. We conclude that felodipine ER is an effective antihypertensive drug which can be administered on a once-daily basis.

ISSN:0263-6352    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

The pharmacological effects of synthetic α-human atrial natriuretic peptide (α-hANP) in patients with Cushing's syndrome and primary aldosteronism were compared with those in normal volunteers. An infusion of synthetic α-hANP at 0.1 µg/kg per min for 20 min produced a maximal plasma hANP level of 800–1200 pg/mI in patients with Cushing's syndrome and primary aldosteronism, and in normal subjects. There were significant decreases in the mean blood pressure ( – 10 to – 15mmHg) in patients with Cushing's syndrome and primary aldosteronism, similar to those in normal subjects. The plasma cyclic 3´5´-guanosine monophosphate (cGMP) concentrations of both groups of patients were increased fivefold over the baseline level following the infusion. Infusion of synthetic α-hANP caused a greater increase in the rate of sodium excretion in patients with Cushing's syndrome and primary aldosteronism compared with normal volunteers. The plasma cortisol and aldosterone concentrations did not, however, significantly change during α-hANP infusion in either the patients with Cushing's syndrome or those with primary aldosteronism. As synthetic α-hANP has a potent hypotensive effect in hypertensive patients with Cushing's syndrome and primary aldosteronism, a significant reduction in blood pressure and natriuresis seems to occur without affecting adrenocortical steroidogenesis.

ISSN:0263-6352    

出版商:OVID    

年代:1989

数据来源: OVID