High blood pressure. Causes, symptoms, treatments

Spironolactone in chronic hemodialysis patients improves cardiac function.

2017-05-28

Androgen-independent prostate cancer cells can undergo apoptosis in response to non-androgen ablative means such as ionizing radiation. Recent evidence documented the ability of alpha-adrenoceptor antagonists, a widely used medical therapy for the treatment of benign prostatic hypertrophy (BPH), to induce apoptosis in benign and malignant prostate cells. In this study, we evaluated the potential additive/synergistic apoptotic effect of alpha1-adrenoceptor antagonists with ionizing radiation against human prostate cancer cells in vitro.

In day 1, PD decreased in both eyes significantly only in tamsulosin and doxazosin groups, but these effects became insignificant at 30 days of treatment (p > 0.05). The control group showed no significant difference in PD (p > 0.05). PD values returned to baseline after the washout period in all groups.

Patients with lower urinary tract symptoms and moderately enlarged prostates initially receiving combination therapy using finasteride and an alpha-blocker are likely to experience no significant symptom deterioration after discontinuing the alpha-blocker after 9 to 12 months of combination therapy regardless of the dose of alpha-blocker chosen.

This prospective, cross-sectional study was conducted at Necip Fazil City Hospital, Kahramanmaras, Turkey. Patients included in the study were grouped as follows: 29 patients treated with tamsulosin (group 1), 27 patients treated with doxazosin (group 2), and 40 untreated controls (group 3). Right eyes of each patient were included in the study. All patients underwent examination with the Pentacam under standard dim light conditions and with undilated pupils. Anterior chamber depth (ACD), anterior chamber volume (ACV), anterior chamber angle (ACA) width, central corneal thickness (CCT), corneal volume (CV), and pupil diameter (PD) were recorded.

The antihypertensive efficacy of the new alpha 1-adrenoceptor antagonist doxazosin is described, and its selectivity for alpha 1-adrenoceptors is reported from both in vivo and in vitro studies. Groups of beagle dogs with chronic perinephritic hypertension were given doxazosin orally, and systolic blood pressure was recorded indirectly from an exteriorized carotid loop. Dogs given doxazosin 0.5 mg kg-1 daily for 10 days showed consistent daily falls in systolic pressure in addition to a progressive reduction in daily pre-dose pressures. A clear indication of antihypertensive action in excess of 24 h post dose was evident. Heart rate changes were minimal. In pentobarbitone anaesthetized dogs pretreated with desimipramine, doxazosin 10-500 micrograms kg-1 i.v. reduced responses of the nictitating membrane to electrical stimulation of the vagosympathetic-depressor nerve trunk (an alpha 1-adrenoceptor response) but had no effect on the chronotropic response of the heart to electrical stimulation of the ansa subclavia. In contrast, the prejunctional alpha 2-adrenoceptor antagonist activity of yohimbine 10-100 micrograms kg-1 i.v. was manifest as a marked dose-related increase in both the heart rate and nictitating membrane responses. The lack of effect of doxazosin on postjunctional alpha 2-adrenoceptors in vivo was demonstrated in the anaesthetized cat. Doxazosin at 50 and 100 micrograms kg-1 i.v. inhibited pressor responses to injected phenylephrine (an alpha 1-adrenoceptor agonist) but had no effect on pressor responses to either alpha-methylnoradrenaline (an alpha 2-adrenoceptor agonist) or angiotensin II.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiotensin-converting enzyme inhibitors are renoprotective in diabetes mellitus through their intrarenal hemodynamic effects. Alpha-1 blockade has variable pre- and postglomerular vasodilatory effects dependent upon the stimulation of the sympathetic nervous system. We tested the hypothesis that the two different classes of drugs have similar renal hemodynamic effects when the patients are examined in an upright position where the sympathetic nervous system is activated. Mean blood pressure (MAP), glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) were examined in 28 hypertensive type-1 diabetic patients with variable degree of nephropathy treated for a mean period of 7.6 +/- 0.4 months with captopril (n = 13) or doxazosin (n = 15). Average treatment doses were 112 +/- 7 mg/day in the captopril group and 8 +/- 1 mg/day in the doxazosin group. Sitting MAP decreased from 118 +/- 3 to 106 +/- 4 mm Hg after captopril (p < 0.05), and from 117 +/- 4 to 110 +/- 3 mm Hg after doxazosin (p = 0.07). GFR and ERPF were unchanged in both groups. The filtration fraction (FF) decreased from 0.27 +/- 0.02 to 0.25 +/- 0.02 after captopril (p < 0.05) and from 0.26 +/- 0.01 to 0.25 +/- 0.01 after doxazosin (p = 0.08). Calculation of 95% confidence intervals of the difference between the post-treatment values as well as the difference between pre- and post-treatment values of MAP, GFR, ERPF and FF of the two drugs indicates no difference in renal hemodynamic response between the drugs. In conclusion, captopril and doxazosin have similar renal hemodynamic responses when the patients are examined in a situation where the sympathetic nervous system is stimulated, and this suggests that doxazosin has a renoprotective effect beyond the blood pressure-lowering effect.