Comparison between perindopril and nifedipine in hypertensive and normotensive diabetic patients with microalbuminuria. Melbourne Diabetic Nephropathy Study Group.

OBJECTIVE--To compare the efficacy of angiotensin converting enzyme inhibition with calcium antagonism in diabetic patients with microalbuminuria. DESIGN--Randomised study of diabetic patients with microalbuminuria treated with perindopril or nifedipine for 12 months and monitored for one or three months after stopping treatment depending on whether they were hypertensive or normotensive. Patients were randomised separately according to whether they were hypertensive or normotensive. SETTING--Diabetic clinics in three university teaching hospitals. PATIENTS--50 diabetic patients with persistent microalbuminuria. In all, 43 completed the study: 30 were normotensive and 13 hypertensive; 19 had type I diabetes and 24 had type II diabetes. INTERVENTIONS--For 12 months 20 patients were given perindopril 2-8 mg daily and 23 were given nifedipine 20-80 mg daily. MAIN OUTCOME MEASURES--Albumin excretion rate, blood pressure, and glomerular filtration rate. RESULTS--Both perindopril and nifedipine significantly reduced mean blood pressure. During treatment there was no significant difference between those treated with perindopril and those treated with nifedipine with respect to albuminuria or mean blood pressure. Stopping treatment with both drugs was associated with a sustained increase in albuminuria and mean blood pressure. There was a significant correlation between mean blood pressure and albuminuria and also between the reduction in mean blood pressure and the decrease in albuminuria during treatment with both drugs. In hypertensive patients both drugs caused significant decreases in mean blood pressure and albuminuria. In normotensive patients there was no significant reduction in albuminuria with either regimen. CONCLUSIONS--In diabetic patients with microalbuminuria blood pressure seems to be an important determinant of urinary albumin excretion. Perindopril and nifedipine have similar effects on urinary albumin excretion, both preventing increases in albuminuria in normotensive patients and decreasing albuminuria in hypertensive patients.     

Value of low dose combination treatment with blood pressure lowering drugs: analysis of 354 randomised trials

Objective To determine the average reduction in blood pressure, prevalence of adverse effects, and reduction in risk of stroke and ischaemic heart disease events produced by the five main categories of blood pressure lowering drugs according to dose, singly and in combination.Design Meta-analysis of 354 randomised double blind placebo controlled trials of thiazides, β blockers, angiotensin converting enzyme (ACE) inhibitors, angiotensin II receptor antagonists, and calcium channel blockers in fixed dose.Subjects 40 000 treated patients and 16 000 patients given placebo.Main outcome measures Placebo adjusted reductions in systolic and diastolic blood pressure and prevalence of adverse effects, according to dose expressed as a multiple of the standard (recommended) doses of the drugs.Results All five categories of drug produced similar reductions in blood pressure. The average reduction was 9.1 mm Hg systolic and 5.5 mm Hg diastolic at standard dose and 7.1 mm Hg systolic and 4.4 mm Hg diastolic (20% lower) at half standard dose. The drugs reduced blood pressure from all pretreatment levels, more so from higher levels; for a 10 mm Hg higher blood pressure the reduction was 1.0 mm Hg systolic and 1.1 mm Hg diastolic greater. The blood pressure lowering effects of different categories of drugs were additive. Symptoms attributable to thiazides, β blockers, and calcium channel blockers were strongly dose related; symptoms caused by ACE inhibitors (mainly cough) were not dose related. Angiotensin II receptor antagonists caused no excess of symptoms. The prevalence of symptoms with two drugs in combination was less than additive. Adverse metabolic effects (such as changes in cholesterol or potassium) were negligible at half standard dose.Conclusions Combination low dose drug treatment increases efficacy and reduces adverse effects. From the average blood pressure in people who have strokes (150/90 mm Hg) three drugs at half standard dose are estimated to lower blood pressure by 20 mm Hg systolic and 11 mm Hg diastolic and thereby reduce the risk of stroke by 63% and ischaemic heart disease events by 46% at age 60-69.     

Trial of atenolol and chlorthalidone for hypertension in black South Africans.

Twenty-four black patients (Zulus) with hypertension participated in a double-blind, placebo-controlled cross-over trial of the efficacy of a beta-blocking agent (atenolol) 100 mg once daily as compared with chlorthalidone 25 mg once daily. The two drugs were also given combined at these doses and the effects compared with those of the drugs given alone. Atenolol as sole treatment had no appreciable effect on blood pressure as compared with placebo. Chlorthalidone produced a small decrease, but this was not statistically significant. Combining the two drugs, however, produced a significant reduction in blood pressure (mean lying blood pressure p < 0.001; mean standing blood pressure p < 0.0002). These findings suggest that beta-blockers should not be regarded as baseline treatment of hypertension in blacks.     

Endpiece: Hospital league tables 1830

ObjectiveTo assess the long term effects of advice to restrict dietary sodium in adults with and without hypertension.DesignSystematic review and meta-analysis of randomised controlled trials.OutcomesMortality, cardiovascular events, blood pressure, urinary sodium excretion, quality of life, and use of antihypertensive drugs.ResultsThree trials in normotensive people (n=2326), five trials in those with untreated hypertension (n=387), and three trials in people being treated for hypertension (n=801) were included, with follow up from six months to seven years. The large high quality (and therefore most informative) studies used intensive behavioural interventions. Deaths and cardiovascular events were inconsistently defined and reported. There were 17 deaths, equally distributed between intervention and control groups. Systolic and diastolic blood pressures were reduced (systolic by 1.1 mm Hg, 95% confidence interval 1.8 to 0.4 mm Hg; diastolic by 0.6 mm Hg, 1.5 to −0.3 mm Hg) at 13 to 60 months, as was urinary 24 hour sodium excretion (by 35.5 mmol/24 hours, 47.2 to 23.9). Degree of reduction in sodium intake and change in blood pressure were not related.ConclusionsIntensive interventions, unsuited to primary care or population prevention programmes, provide only small reductions in blood pressure and sodium excretion, and effects on deaths and cardiovascular events are unclear. Advice to reduce sodium intake may help people on antihypertensive drugs to stop their medication while maintaining good blood pressure control.

What is already known on this topic

Restricting sodium intake in people with hypertension reduces blood pressureLong term effects (on blood pressure, mortality, and morbidity) of reduced salt intake in people with and without hypertension are unclear

What this study adds

Few deaths and cardiovascular events have been reported in salt reduction trialsMeta-analysis shows that blood pressure was reduced (systolic by 1.1 mm Hg, diastolic by 0.6 mm Hg) at 13 to 60 months, with a reduction in sodium excretion of almost a quarter (35.5 mmol/24 hours)The interventions used were highly intensive and unsuited to primary care or population prevention programmesLower salt intake may help people on antihypertensive drugs to stop their medication while maintaining good control of blood pressure, but there are doubts about effects of sodium reduction on overall health     

The construction of endothelial cellular biosensing system for the control of blood pressure drugs

In order to assess blood pressure control drugs, the endothelial cellular biosensing system for assessing blood pressure control drugs was constructed. This system consists of human umbilical vein endothelial cells (HUVEC) on a polyion-coated gold electrode, a platinum counter electrode and an Ag/AgCl reference electrode. Nitric oxide (NO) as an indicator of blood vessel relaxation was detected with a polyion-coated electrode in the system. The NO detection limit of this electrode was 8.4 nM by differential pulse voltammetry (DPV). The drugs of blood pressure control (acetylcholine chloride (AcChCl), NOC 7 and NG-monomethyl-L-arginine (L-NMMA)) were assessed with this endothelial cellular biosensing system. One milli molar of AcChCl make NO released from HUVEC stimulated by activating endothelial nitric oxide synthase (eNOS) in HUVEC. In the case of 5 mM of L-NMMA, NO releasing was inhibited by inhibiting eNOS activation by 1 mM of AcChCl. NOC 7 immediately released NO regardless of eNOS activation in endothelial cells.     

Veratrum viride; hypotensive and cardiac effects of intravenous use

The hypotensive action of veratrum viride given intravenously was studied in 24 patients, 22 of them hypertensive and 2 normotensive. Vasodepression of considerable but variable degree was obtained in all patients. Maximum hypotension occurred 8 to 15 minutes after injection and relative hypotension usually lasted at least two hours. In four patients subnormal hypotension occurred but there were no clinical manifestations of shock. The blood pressure rose promptly when pressor drugs were administered.A dose of 0.3 to 0.5 mg. brought about a satisfactory decrease in blood pressure. The degree of decrease was affected by the speed of administration and in a few patients by idiosyncratic sensitivity to the drug. Veratrum has an extravagal action on the pulse rate, and in that and other respects resembles digitalis. Veratrum should be given with caution to digitalized patients. Atropine reduced but did not abolish the hypotensive effect of veratrum, and was more effective when given before veratrum. This indicates that the parasympathomimetic action of veratrum is important in the mechanism of blood pressure reduction.     

Natural progesterone and antihypertensive action.

In a placebo controlled, double blind crossover study natural progesterone was given by mouth, in increasing doses, to six men and four postmenopausal women with mild to moderate hypertension who were not receiving any other antihypertensive drugs. When compared with values recorded before treatment and during administration of placebo progesterone caused a significant reduction in blood pressure, suggesting that progesterone has an antihypertensive action rather than a hypertensive one as has been previously thought. This possible protective effect of progesterone should be investigated further.     

Contribution of atenolol,bendrofluazide, and hydrallazine to management of severe hypertension.

The efficacy of various combinations of atenolol, bendrofluazide, and hydraliazine given twice daily was assessed in a double-blind trial on 39 patients with moderate to severe essential hypertension. Concurrent treatment with all three drugs proved most effective and produced a mean reduction in blood pressure of 43/31 mm Hg. In the dosage used, hydrallazine affected only the diastolic blood pressure, and when added to either bendrofluazide or bendrofluazide plus atenolol it produced a further mean reduction in pressure of 6 mm Hg. Once-daily treatment with atenolol and bendrofluazide was as effective in reducing blood pressure as the same combination given twice daily, and the hypotensive effect was still present at least 24 hours after the last dose of tablets. A combined tablet of atenolol and bendrofluazide taken once daily would be a simple regimen to follow and would provide almost as much hypotensive effect as a twice-daily regimen incorporating a modest dose of hydrallazine. The hypotensive effect of atenolol was equal to that of bendrofluazide on systolic pressure but significantly better than that of bendrofluazide on diastolic pressure. Atenolol reduced plasma renin and urate concentrations but increased plasma potassium levels. The biochemical effects of atenolol, therefore, may be an advantage over those of bendrofluazide when deciding on first-line treatment for essential hypertension.     

Ambulatory blood pressure during once-daily randomised double-blind administration of atenolol,metoprolol, pindolol,and slow-release propranolol

Intra-arterial ambulatory blood pressure was measured over 24 hours, in 34 patients with newly diagnosed hypertension, both before and after double-blind randomisation to treatment with atenolol (n=9), metoprolol (n=9), pindolol (n=9), or propranolol in its slow-release form (n=7). The dosage of each drug was adjusted at monthly clinic visits until satisfactory control of blood pressure was achieved (140/90 mm Hg or less by cuff) or the maximum dose in the study protocol was reached. A second intra-arterial recording was made after these drugs had been taken once daily at 0800 for three to eight months (mean 5·0±SD 1·4) and was started four hours after the last dose.At the end of the 24-hour recordings blood pressure was significantly lower with all four drugs. The extent to which the drugs reduced blood pressure, however, differed over the 24 hours. Atenolol lowered mean arterial pressure significantly throughout all 24 recorded hours, metoprolol for 12 hours, pindolol for 15 hours, and slow-release propranolol for 22 hours. Neither metoprolol nor pindolol lowered blood pressure during sleep. A significant reduction in heart rate was observed over 20 hours with atenolol, 20 hours with metoprolol, 10 hours with pindolol, and 24 hours with slow-release propranolol. Atenolol, metoprolol, and slow-release propranolol continued to slow the heart rate 24 hours after the last tablet was taken; this effect on heart rate, however, was not sustained throughout the second morning in those patients taking atenolol. Pindolol, the only drug studied that has intrinsic sympathomimetic activity, increased heart rate and did not lower blood pressure during sleep.Atenolol and slow-release propranolol are effective as antihypertensive agents over 24 hours when taken once daily, whereas metoprolol and pindolol may need to be taken more frequently. At times of low sympathetic tone, however, such as during sleep, beta-blockers with intrinsic sympathomimetic activity may raise heart rate and attenuate the fall in blood pressure with treatment.     

Evaluation of computer based clinical decision support system and risk chart for management of hypertension in primary care: randomised controlled trial

ObjectivesTo investigate the effect of a computer based clinical decision support system and a risk chart on absolute cardiovascular risk, blood pressure, and prescribing of cardiovascular drugs in hypertensive patients.DesignCluster randomised controlled trial.Setting27 general practices in Avon.Participants614 patients aged between 60 and 79 years with high blood pressure.InterventionsPatients were randomised to computer based clinical decision support system plus cardiovascular risk chart; cardiovascular risk chart alone; or usual care.ResultsPatients in the computer based clinical decision support system and chart only groups were no more likely to have cardiovascular risk reduced to below 10% than patients receiving usual care. Patients in the computer based clinical decision support group were more likely to have a cardiovascular risk ⩾10% than chart only patients, odds ratio 2.3 (95% confidence interval 1.1 to 4.8). The chart only group had significantly lower systolic blood pressure compared with the usual care group (difference in means −4.6 mm Hg (95% confidence interval −8.4 to −0.8)). Reduction of diastolic blood pressure did not differ between the three groups. The chart only group were twice as likely to be prescribed two classes of cardiovascular drugs and over three times as likely to be prescribed three or more classes of drugs compared with the other groups.ConclusionsThe computer based clinical decision support system did not confer any benefit in absolute risk reduction or blood pressure control and requires further development and evaluation before use in clinical care can be recommended. Use of chart guidelines are associated with a potentially important reduction in systolic blood pressure.     

Suprarenal aortic flow reduction versus angiotensin I infusion in fetal sheep

In the unanaesthetized fetal sheep, long-term suprarenal aortic blood flow reduction will cause upper body arterial blood pressure to increase. To see if the response to this procedure was entirely due to the concomitant increase in plasma renin activity, we gave an angiotensin I infusion of several days to 7 fetal sheep and compared their responses to those of 4 fetal sheep undergoing partial occlusion of the aorta above the renal arteries. Both protocols caused upper body arterial blood pressure to increase to comparable levels. Angiotensin I infusion had no effect upon venous blood pressure while suprarenal aortic blood flow reduction caused a significant increase in venous blood pressure as early as 1 day after blood flow reduction. Haematocrits were unchanged in the fetuses with flow restriction but increased in the infused fetuses. We conclude that long-term angiotensin I infusion in the fetus does not mimic the entire complex of responses to suprarenal aortic blood flow reduction.     

Effects of drugs interfering with the metabolism of octopamine on blood pressure of rats

1. p-Octopamine injected in lateral ventricle of conscious spontaneously hypertensive rats decreased systolic blood pressure (SBP). 2. Precursors of octopamine--tyrosine, tyramine and phenylethanolamine (PEA)--had the same effect. The administration of pargyline, a MAO inhibitor, which increased brain octopamine, resulted in a reduction of systolic blood pressure; and this decrease was greater after administration of octopamine precursors and PEA. 3. Similarly, drugs known to inhibit activity of phenylethanolamine N-methyl-transferase (PNMT) and to increase brain octopamine level such as SKF 64139 and DCMB decreased SBP. 4. p-Octopamine hypotension was not antagonized by piperoxan, yohimbine and prazosin, a relatively selective antagonist of post-synaptic alpha adrenoceptors. 5. These results suggest that octopamine may be involved in central blood pressure regulation, and the receptors sensitive to octopamine appeared to be distinct from those receptive to the catecholamines.     

冠心病患者血压控制水平现况

目的：评估目前我国冠心病患者血压控制水平,为冠心病的二级预防及进一步治疗提供指导依据。方法：收集2011~2014年在解放军总医院及海南分院心内科住院治疗的1 230例冠心病患者,分析不同手术方式：经皮冠状动脉介入治疗（PCI）、冠状动脉旁路移植术（CABG）、二级预防用药情况（阿司匹林、氯吡格雷、硝酸酯类、曲美他嗪、尼可地尔、降压药、降糖药、降脂药）及不同生活方式（吸烟、饮酒、锻炼）下血压控制率的差异。结果：①手术方式对血压影响：CABG组男性收缩压及舒张压均低于PCI组及对照组,CABG组女性舒张压低于PCI组。②二级预防药物的使用情况：血压不达标组在曲美他嗪、利尿剂、钙拮抗剂、β受体阻滞剂、ACEI/ARB使用率上显著高于血压正常组。③生活方式情况：吸烟的冠心病患者血压达标率显著低于不吸烟的冠心病患者,是否饮酒及锻炼在血压达标率上没有表现显著差异。结论：冠心病患者血压控制仍不理想,CABG术较PCI术可能更有利于冠心病患者血压的控制,戒烟及提高冠心病二级预防药物的使用率仍是血压控制主要手段。     

Hypertension: comparison of drug and non-drug treatments.

Thirty-seven reports of the treatment of hypertension by non-pharmacological means were compared with the results of treatment by standard drug regimens. Treatment by drugs produced the greatest lowering of blood pressure. Treatment by weight reduction, yoga, and muscle relaxation each produced smaller, but appreciable, changes in blood pressure biofeedback, and salt restriction were inferior to those of the other regimens and were not significantly different to the effects of placebo treatment. Large comparative trials of pharmacological and non-pharmacological treatments are needed before definite conclusions can be made.     

Debate: Does it matter how you lower blood pressure?

Whether it matters how pressure is lowered has been debated since antihypertensive drugs proved to prevent cardiovascular events. However, in clinical trials, while the stroke benefit predicted by a given difference in blood pressure was achieved, the results for myocardial infarction were roughly half that expected. This suggested that adverse drug effects of diuretics and β-blockers might have detracted from their hypotensive effects. Trials with newer antihypertensive classes have revealed superior effects on outcomes associated with converting enzyme inhibitor use, and that α-blockers are less cardioprotective than diuretics. These studies establish that simple blood pressure reduction is an inadequate guide to therapy. The challenge now will be to determine the optimal therapy for each hypertensive patient.     

DRUG THERAPY OF HYPERTENSION

Drug therapy can lower the blood pressure levels of most hypertensive patients. The agents now in use are usually better tolerated and more effective than many of those available a few years ago. It seems probable that there is a close relationship between the elevated blood pressure and the increased mortality rate of hypertensive persons and that a significant lowering of this pressure would result in a decrease in mortality.In a pertinent study, the average pre-treatment blood pressure of a group of 76 patients with moderate to severe hypertension was 198/119 mm. of mercury in the prone position and 192/118 in the standing position. The patients were treated for a two-year period and with treatment their average pressure over a nine-month period was 164/99 mm. prone and 142/94 mm. standing.Many drugs used for the treatment of high blood pressure have more effect on the lowering of this pressure when the patient is in the standing position. For this reason, the blood pressure, while the patient is standing, should be used as the guide for dosage of these drugs.     

Relation between mortality and treated blood pressure in elderly patients with hypertension: report of the European Working Party on High Blood Pressure in the Elderly.

OBJECTIVE--To investigate the relation between mortality and treated systolic and diastolic blood pressures. DESIGN--Randomised double blind placebo controlled trial. Mortality in the two treatment groups was examined in thirds of treated systolic and diastolic blood pressures. PATIENTS--339 And 352 patients allocated to placebo and active treatment, respectively. The groups were similar at randomisation in sex ratio (70% women), mean age (71.5 years), blood pressure (182/101 mm Hg), and proportion of patients with cardiovascular complications (35%). MEASUREMENTS AND MAIN RESULTS--In the placebo group total mortality rose with increasing systolic pressure whereas it had a U shaped relation with diastolic pressure, the total lowest mortality being in patients in the middle third of the distribution of diastolic pressure. In the group given active treatment total mortality showed a U shaped relation with systolic pressure and an inverse association with treated diastolic pressure. In both groups cardiovascular and non-cardiovascular mortality followed the same trends as total mortality. The increased mortality in the lowest thirds of pressure was not associated with an increased proportion of patients with cardiovascular complications at randomisation or with a fall in diastolic pressure exceeding the median fall in pressure in each group. In contrast, patients in the lowest thirds of pressure showed greater decreases in body weight and haemoglobin concentration than those in the middle and upper thirds of pressure. CONCLUSIONS--In patients taking active treatment total mortality was increased in the lowest thirds of treated systolic and diastolic blood pressures. This increased mortality is not necessarily explained by an exaggerated reduction in pressure induced by drugs as for diastolic pressure a U shaped relation also existed during treatment with placebo. In addition, patients in the lowest thirds of systolic and diastolic pressures were characterised by decreases in body weight and haemoglobin concentration, and the patients in the lowest thirds of diastolic pressure taking active treatment also by an increased non-cardiovascular mortality, suggesting some deterioration of general health.     

Perioperative Use of Clevidipine: A Systematic Review and Meta-Analysis

Background

Clevidipine is an ultrashort-acting drug for rapid reduction of blood pressure by selectively acting on the L-type Ca2+ channels on arteriolar smooth muscle. The drug’s ultrashort action in reducing the blood pressure is due to its rapid hydrolysis by blood and extravascular tissue esterases, which does not depend on hepato-renal metabolism and excretion. An analysis of the perioperative management of blood pressure should be considered to compare with other intravenous antihypertensive agents.

Methods

Analyses of the available evidence in randomized clinical trials following the PRISMA methodology as well as clinical significance according to the GRADE system were conducted. Placebo versus other antihypertensive drugs studies were included. Statistical assessments were done using the X2 and I2 tests.

Results

Clevidipine was more effective in maintaining the blood pressure within pre-specified ranges compared with other antihypertensive drugs (MD, -17.87 CI 95%: -29.02 to -6.72; p = 0.02). The use of Clevidipine versus placebo and rescue antihypertensive intravenous drug showed a clear reduction in rates of treatment failure (RR 0.10; IC 95%; 0.05–0.18; p <0.0001). There was no difference in the incidence of adverse events compared with placebo (RR 1.47; 95% CI 0.89 to 2.43, p = 0.14) and with other antihypertensive drugs (RR 0.78, 95% CI 0.45 to 1.35; p = 0.37). In addition, there was no difference in the incidence of atrial fibrillation (AF) between clevidipine and control groups (RR 1.09, IC del 95%: 0.65 a 1.83; p = 0.73).

Conclusions

Clevidipine is an ultrafast-acting drug that is highly effective for management of perioperative arterial hypertension. It is devoid of adverse effects associated with the use of other IV antihypertensives. Its favorable pharmacodynamic and pharmacokinetic properties make clevidipine the drug of choice for the management of acute perioperative hypertension. It is important to emphasize the need for further studies with a larger number of patients to confirm these findings and increase the degree of evidence.     

Renin concentrations and effects of propranolol and spironolactone in patients with hypertension.

In a crossover study 32 patients with hypertension were randomly allocated to treatment with spironolactone 200 mg/day for two months, propranolol 320 mg/day for two months, and a combination of both drugs at half the dose. Between the treatments placebo was given for two months. Both spironolactone and propranolol lowered the blood pressure significantly in both positions. The initial plasma renin activity (PRA) levels ranged from 0-4 to 5-0 mug angiotensin I l-1 h-1, and there was a close correlation between these levels and the effects of the drugs: with increasing PRA the response to propranolol was better while the opposite was true for spironolactone. Spironolactone reduced the blood pressure more at eight than at four weeks, while no such difference could be shown for propranolol. Spironolactone and propranolol together decreased the blood pressure still further irrespective of the initial PRA. All patients achieved a normal supine blood pressure.     

Progesterone is not responsible for the blood pressure fall in late-pregnant New Zealand genetically hypertensive rats

In various models of experimental and genetic hypertension in rats, blood pressure is markedly reduced during late pregnancy. The period during which the blood pressure reduction occurs is also the period when plasma progesterone is maximally elevated, and administration of progesterone to renal hypertensive rats has been reported to reduce blood pressure (J. Armstrong, 1959, Proc. Soc. Exp. Biol. Med. 102:452-455). To test the possibility that elevated plasma progesterone is responsible for the blood pressure reduction in late pregnancy, on Day 14 of pregnancy a group of New Zealand genetically hypertensive (NZGH) rats was ovariectomized and implanted with progesterone-filled capsules, to maintain plasma progesterone at low levels just sufficient to maintain pregnancy, and compared with intact, pregnant NZGH. Ovariectomy did not alter the characteristic course of blood pressure reduction seen in late-pregnant intact NZGH rats. In addition, daily administration of progesterone (15 mg/kg, sc) for 14 days did not alter blood pressure of either nonpregnant NZGH rats or New Zealand normotensive rats with chronic 1-kidney, 1-clip hypertension. It is concluded that blood pressure of NZGH rats is reduced to near normotensive levels in late pregnancy, as reported for other models of rat hypertension, but that elevated plasma progesterone levels are not requisite for that reduction and do not reduce blood pressure of renal hypertensive rats.