摘要:

ObjectivesTo determine whether the dietary-fat-induced increase in blood pressure is caused by excess energy intake or the fat composition of the diet, what type of fat increases the blood pressure, and whether insulin resistance is involved in the dietary-fat-induced increase in blood pressure.MethodsIn a series of experiments, rats received: chow alone or chow supplemented with lard or sucrose to provide 33% of a total energy content increased by 50%; chow alone or chow in which 50% of the energy content was from substituted lard, safflower oil or medium-chain triglyceride oil; or chow alone or chow in which 50% of the energy content was from substituted lard, with or without troglitazone. Systolic blood pressure (SBP) was measured every week during each 8-week feeding period. A steady state serum glucose method was used to determine the insulin sensitivity after the lard substitution with or without troglitazone.ResultsBoth the lard and sucrose enrichment increased SBP and body weight compared with controls. Lard substitution significantly increased SBP and immunoreactive insulin, although body weight did not differ from control. Neither a diet substituted with safflower oil nor one substituted with medium-chain triglyceride oil influenced SBP. Troglitazone completely inhibited the increase in SBP and immunoreactive insulin induced by the lard. The steady-state serum glucose concentration was significantly greater after the lard substitution than after isoenergetic chow; this effect also was reversed by troglitazone.ConclusionChronic feeding with lard increased SBP in rats, independently of excess energy intake. Of the fats tested, lard exerted an intrinsic pressor effect. Troglitazone reversed the lard-induced increase in SBP.

ISSN:0263-6352    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

ObjectivesTo assess the acute effect of sildenafil citrate on blood pressure and heart rate in men with erectile dysfunction taking concomitant antihypertensive medication.DesignPost-hoc subanalysis of five, 12- or 24-week, prospective, randomized, double-blind, placebo-controlled studies.SettingPrivate-practice and academic urology clinics.PatientsA total of 1685 men with erectile dysfunction of ≥ 6 months duration, of whom 667 (sildenafiln= 406, placebon= 261) were taking antihypertensive medication (diuretic, β-blocker, α-blocker, angiotensin converting enzyme inhibitor, and/or calcium antagonist). Of the patients taking antihypertensive medication, 608 (91%) completed the studies (374 of 406 receiving sildenafil, 234 of 261 receiving placebo).InterventionsThe last dose of oral sildenafil (25–200 mg) or placebo was taken at home on the morning of the final clinic visit. Patients taking antihypertensive medication maintained usual dosing schedules.Main outcome measurementsSitting systolic (SBP)/ diastolic blood pressure (DBP) and heart rate at baseline and after dosing with sildenafil or placebo (end-of-treatment visit).ResultsMean changes from baseline in SBP/DBP for men taking antihypertensive medication were −3.6/−1.9 mmHg for those receiving sildenafil and −0.8/−0.1 mmHg for those receiving placebo compared with −2.2/−2.0 mmHg and −0.1/0.4 mmHg, respectively, for men not taking antihypertensive medication. Mean changes from baseline in heart rate for men taking antihypertensive medication were −0.6 beats/min after sildenafil and −0.9 beats/min after placebo compared with 0.4 beats/min and −0.6 beats/min, respectively, for patients not taking antihypertensive medication. Differences in SBP, DBP, and heart rate between the patients taking and those not taking antihypertensive medication were small.ConclusionsThe acute, short-term effects of oral sildenafil on blood pressure and heart rate in men with erectile dysfunction were small and not likely to be clinically significant in those taking concomitant antihypertensive medication.

ISSN:0263-6352    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

ObjectiveThe aim of this study was to compare the chronic effects of four dihydropyridine calcium antagonists with different pharmacologic characteristics, amlodipine, felodipine, lacidipine and manidipine, on blood pressure (BP), heart rate (HR) and plasma norepinephrine (NE) levels in patients with mild to moderate essential hypertension.MethodAfter a 4-week placebo period, 60 patients of both sexes were randomly administered amlodipine 5–10 mg once daily (o.d.) (n= 15); felodipine 5–10 mg o.d. (n= 15); lacidipine 4–6 mg o.d. (n= 15); manidipine 10–20 mg o.d. (n= 15), for 24 weeks, according to a double blind, parallel group design. Initially, for the first 2 weeks, the lowest dose of each drug was used, then higher doses were administered if sitting diastolic blood pressure (DBP) was > 90 mmHg. BP, HR and plasma NE were evaluated at the end of the placebo and active treatment periods. NE was assessed at trough, at peak and after 12 h from drug ingestion.ResultsAdministration of all four drugs reduced clinic BP to the same level after 24 weeks, whereas HR increased only with felodipine (+ 3.1 bpm;P< 0.05). Significant increases in plasma NE levels were observed after chronic therapy with amlodipine and felodipine (+ 34.9 and + 39.4% respectively;P< 0.01 versus placebo) but not with lacidipine (+ 7.1%, NS) and manidipine (+ 2.9%, NS).ConclusionsThese findings suggest that sympathetic activation occurred during chronic treatment with amlodipine and felodipine, whereas manidipine and lacidipine did not increase plasma noradrenaline at the times measured. The reasons for this difference are unclear; they could be related to the different pharmacological characteristic of the two drugs, lacidipine and manidipine.

ISSN:0263-6352    

出版商:OVID    

年代:2000

数据来源: OVID

ISSN:0263-6352    

出版商:OVID    

年代:2000

数据来源: OVID