Effects of antihypertensive drugs on autoregulation  of RBF and glomerular capillary pressure in SHR

The relationship between systemic blood pressure and glomerular capillary pressure (Pgc) in spontaneously hypertensive rats (SHR) during treatment with antihypertensive drugs is still unclear. The effects of an angiotensin-converting enzyme inhibitor (enalapril), two calcium channel antagonists (nifedipine and verapamil), and an α1-receptor blocker (doxazosin) on renal blood flow (RBF) autoregulation, Pgc, and renal segmental resistances were therefore studied in SHR. Recordings of RBF autoregulation were done before and 30 min after intravenous infusion of the different drugs, and Pgcwas thereafter measured with the stop-flow technique. When the mean arterial pressure (MAP) was reduced to ∼120 mmHg by infusions of doxazosin or enalapril, the lower pressure limit of RBF autoregulation was reduced significantly. Nifedipine or verapamil abolished RBF autoregulation. Doxazosin did not change Pgc (43.6 ± 1.4 vs. 46.7 ± 1.5 mmHg in controls, P > 0.5), enalapril lowered (41.3 ± 0.8 mmHg, P < 0.01), and the calcium channel antagonists increased Pgc[53.7 ± 1.4 mmHg (nifedipine) and 54.8 ± 1.2 mmHg (verapamil), P < 0.01]. When MAP was reduced to ∼85 mmHg by drugs, Pgc was reduced to 43.3 ± 1.7 mmHg after nifedipine ( P > 0.2 vs. control), whereas Pgc after enalapril was 38.5 ± 0.5 mmHg ( P < 0.05 vs. control). Enalapril reduced Pgc mainly by reducing efferent resistance. During treatment with calcium channel antagonists, Pgc became strictly dependent on MAP. Monotherapy with nifedipine may increase Pgc and by this mechanism accelerate glomerulosclerosis if a strict blood pressure control is not obtained.

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Abstract 104: Dynamic Autoregulation of Glomerular Capillary Pressure

Hypertension ◽

10.1161/hyp.68.suppl_1.104 ◽

2016 ◽

Vol 68 (suppl_1) ◽

Author(s):

Scott C Thomson

Keyword(s):

Blood Pressure ◽

Time Series ◽

Blood Flow ◽

Capillary Pressure ◽

Tubuloglomerular Feedback ◽

Step Response ◽

Glomerular Capillary ◽

Arterial Blood ◽

Glomerular Capillary Pressure ◽

Step Responses

It is generally accepted that renal blood flow (RBF) autoregulation is mediated by myogenic and tubuloglomerular feedback responses acting on the pre-glomerular resistance. If this is so, then autoregulation of RBF and glomerular capillary pressure (PGC) should change in the same direction throughout an autoregulatory step response. We computed autoregulatory step responses from time series recordings of arterial blood pressure (BP) and RBF (Transonics) blood flow or tubular stop-flow pressure (micropuncture), which is a surrogate for PGC in Wistar-Froemter rats fed for one week on low or high salt diets (n=6-10 ). Autoregulatory step responses were generated from time series by an algorithm that treats BP as a leading indicator of RBF or PGC and uses the projection theorem to solve for the impulse response which is integrated to obtain the step response. Step responses shown in the figure represent the uncompensated changes in RBF and PGC (mean + SEM) following a 1 mmHg BP step. The data clearly reveal that the time courses of RBF and PGC differ such that changes in RBF cannot predict changes in PGC. This implies that the renal hemodynamic response to a blood pressure disturbance is not confined to the pre-glomerular resistance. Furthermore, the participation of post-glomerular resistance in the autoregulatory response is sensitive to dietary salt such that PGC is more sensitive to BP on low salt diet.

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Decreased nephron population resulting from increased ureteral pressure

American Journal of Physiology-Legacy Content ◽

10.1152/ajplegacy.1964.207.4.835 ◽

1964 ◽

Vol 207 (4) ◽

pp. 835-839 ◽

Cited By ~ 24

Author(s):

Richard L. Malvin ◽

Howard Kutchai ◽

Fred Ostermann

Keyword(s):

Blood Pressure ◽

Hydrostatic Pressure ◽

Capillary Pressure ◽

Mean Blood Pressure ◽

Glomerular Capillary ◽

Glomerular Capillary Pressure ◽

Anesthetized Dogs ◽

The Mean

The glucose Tm and GFR were determined for each kidney in anesthetized dogs. After three control periods a hydrostatic pressure was applied to one ureter. This resulted in a decrease in GFR over all ranges of ureteral pressures. Tm glucose remained essentially unchanged until the ureteral pressure was elevated to more than 30% of mean blood pressure. At ureteral pressures greater than this, Tm glucose was significantly depressed. The data were used in an attempt to calculate the range and the mean glomerular capillary pressure.

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Cytochrome P-450 inhibitors alter afferent arteriolar responses to elevations in pressure

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1994.266.5.h1879 ◽

1994 ◽

Vol 266 (5) ◽

pp. H1879-H1885 ◽

Cited By ~ 21

Author(s):

J. D. Imig ◽

A. P. Zou ◽

P. R. Ortiz de Montellano ◽

Z. Sui ◽

R. J. Roman

Keyword(s):

Capillary Pressure ◽

Perfusion Pressure ◽

Pressure Control ◽

Renal Perfusion ◽

Renal Perfusion Pressure ◽

Glomerular Capillary ◽

Glomerular Capillary Pressure ◽

Afferent Arterioles ◽

Cytochrome P 450

The present study evaluated the effects of cytochrome P-450 inhibitors on the response of the renal microvasculature to changes in renal perfusion pressure and on autoregulation of glomerular capillary pressure using the rat juxtamedullary nephron microvascular preparation perfused in vitro with a cell-free perfusate containing 5% albumin. The basal diameters of the proximal and distal afferent arterioles averaged 28 +/- 1 (n = 32) and 18 +/- 1 micron (n = 23), respectively, at a control perfusion pressure of 80 mmHg. The diameters of these vessels decreased by 8% when perfusion pressure was elevated from 80 to 160 mmHg. After addition of cytochrome P-450 inhibitors (either 17-octadecynoic acid, 20 microM; 7-ethoxyresorufin, 10 microM; or miconazole, 20 microM) to the perfusate, the diameters of the proximal and distal afferent arterioles increased by 6% in response to the same elevation in perfusion pressure. Control glomerular capillary pressure averaged 43 +/- 1 mmHg (n = 32) at a renal perfusion pressure of 80 mmHg and increased by only 9 +/- 1 mmHg when perfusion pressure was elevated to 160 mmHg. Autoregulation of glomerular capillary pressure was impaired after addition of the cytochrome P-450 inhibitors, and it increased by 18 +/- 2 mmHg when perfusion pressure was varied over the same range. These results indicate that cytochrome P-450 inhibitors attenuate the vasoconstrictor response of afferent arterioles to elevations in renal perfusion pressure and impair autoregulation of glomerular capillary pressure, suggesting a possible role for cytochrome P-450 metabolites of arachidonic acid in these responses.

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Initial angiotensin-converting enzyme inhibitor/calcium channel blocker combination therapy achieves superior blood pressure control compared with calcium channel blocker monotherapy in patients with stage 2 hypertension*1

American Journal of Hypertension ◽

10.1016/j.amjhyper.2004.02.003 ◽

2004 ◽

Vol 17 (6) ◽

pp. 495-501 ◽

Cited By ~ 82

Author(s):

K JAMERSON

Keyword(s):

Blood Pressure ◽

Combination Therapy ◽

Angiotensin Converting Enzyme ◽

Calcium Channel ◽

Angiotensin Converting Enzyme Inhibitor ◽

Calcium Channel Blocker ◽

Channel Blocker ◽

Enzyme Inhibitor ◽

Pressure Control ◽

Converting Enzyme

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HYT-Hypertension in Turkey: A Cross-Sectional Survey on Blood Pressure Control with Calcium Channel Blockers Alone or Combined with Other Antihypertensive Drugs

High Blood Pressure & Cardiovascular Prevention ◽

10.1007/s40292-015-0091-6 ◽

2015 ◽

Vol 22 (2) ◽

pp. 165-172 ◽

Cited By ~ 3

Author(s):

Gino Seravalle ◽

Nevrez Koylan ◽

Istemi Nalbantgil ◽

Nail Caglar ◽

Fosca Quarti-Trevano ◽

...

Keyword(s):

Blood Pressure ◽

Calcium Channel ◽

Blood Pressure Control ◽

Calcium Channel Blockers ◽

Antihypertensive Drugs ◽

Pressure Control ◽

Channel Blockers ◽

Cross Sectional Survey ◽

Cross Sectional

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THE USE OF MEDICINES IN TREATING HYPERTENSION IN HUE UNIVERSITY HOSPITAL

Journal of Medicine and Pharmacy ◽

10.34071/jmp.2016.2.11 ◽

2016 ◽

pp. 76-84

Author(s):

Khoa Bao Chau Thai ◽

Thi Hong Phuong Vo

Keyword(s):

Blood Pressure ◽

Channel Blocker ◽

Enzyme Inhibitor ◽

Antihypertensive Drugs ◽

Good Prognosis ◽

Target Blood Pressure ◽

University Hospital ◽

Key Words Hypertension ◽

Cross Sectional ◽

Positive Effects

Background: Hypertension is a common condition in the world as well as in Viet Nam. If hypertension isn’t treated well, it can cause many serious complications. Controlling target blood pressure will bring positive effects on reducing mortality rate and also disabilities caused by diseases related to hypertension. Objectives: (1) Analyzing the use of medicines in treating hypertension. (2) Evaluating the effects of medicine usage in treating hypertension at the hospital of Hue University of Medicine and Pharmacy. Materials and methods: 388 patients were diagnosed as having hypertension with inpatient care at the Cardiovascular Department of Hue University of Medicine and Pharmacy’s hospital, using cross-sectional descriptive study methods. Results: All antihypertensive drugs in the research were contained in the antihypertensive list recommended by Vietnamese Society of Cardiology. Angiotensin converting enzyme inhibitor and calcium channel blocker were the two most popular drug groups (96.6% and 71.4%, respectively). The rate of using multi-therapy regimens was higher than the rate of using uni-therapy regimens in both initial therapies (64.7%>35.3%) and final therapies (61.9%>38.1%). The rate of patients having interactions between antihypertensive drugs and the other kinds of drugs was 7.5%. The rate of patients having reasonable prescriptions was 84.3%. Evaluating the effects of medicine usage in treatments showed that the rate of patients reaching target blood pressure before leaving the hospital was 67.3%. Most patients were evaluated as having good prognosis after treatment, up to 81.7%. Conclusions: All antihypertensive drugs in the research were contained in the antihypertensive list recommended by Vietnamese Society of Cardiology. The rate of using multi-therapy regimens was higher than the rate of using uni-therapy regimens. The rate of drug interactions was quite low; most patients were evaluated as having good prognosis after treatment. Key words: hypertension, antihypertensive drugs.

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Circadian rhythm of the intrarenal renin–angiotensin system is caused by glomerular filtration of liver-derived angiotensinogen depending on glomerular capillary pressure in adriamycin nephropathy rats

Hypertension Research ◽

10.1038/s41440-021-00620-6 ◽

2021 ◽

Author(s):

Takashi Matsuyama ◽

Naro Ohashi ◽

Taro Aoki ◽

Sayaka Ishigaki ◽

Shinsuke Isobe ◽

...

Keyword(s):

Circadian Rhythm ◽

Glomerular Filtration ◽

Capillary Pressure ◽

Renin Angiotensin System ◽

Angiotensin System ◽

Renin Angiotensin ◽

Glomerular Capillary ◽

Glomerular Capillary Pressure ◽

Adriamycin Nephropathy

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Improvement of Blood Pressure Control by Adherence Check in Patients With Apparent Treatment-Resistant Hypertension: A Case Series

Clinical Medicine Insights Case Reports ◽

10.1177/1179547620904884 ◽

2020 ◽

Vol 13 ◽

pp. 117954762090488

Author(s):

Keiko Hosohata ◽

Ayaka Inada ◽

Saki Oyama ◽

Takashi Doi ◽

Iku Niinomi ◽

...

Keyword(s):

Blood Pressure ◽

Resistant Hypertension ◽

Antihypertensive Drugs ◽

Case Series ◽

Pressure Control ◽

Supporting Evidence ◽

Treatment Resistant ◽

Uncontrolled Blood Pressure ◽

Important Challenge ◽

Prescribed Medicines

Adherence to medications is an important challenge while treating chronic disease such as resistant hypertension, which is defined as uncontrolled blood pressure (BP) despite treatment with more than 3 antihypertensive drugs to achieve targets. It is possible that poor adherence is the most significant contributor to rates of pseudo-resistance among treated hypertensive patients. In this report, we describe 4 patients with apparent treatment-resistant hypertension, who received intervention to promote adherence by pharmacists who set the prescribed medicines in a weekly medication calendar and conducted a weekly pill count. The results showed that the intervention of pharmacists to medication adherence improved systolic BP in patients with apparent treatment-resistant hypertension; however, further controlled trials are required to strengthen supporting evidence.

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Blood Pressure Control: Stroke and Stroke Prevention

Journal of the Renin-Angiotensin-Aldosterone System ◽

10.1177/14703203050060010301 ◽

2005 ◽

Vol 6 (1_suppl) ◽

pp. S8-S11

Author(s):

Hans-Christoph Diener

Keyword(s):

Blood Pressure ◽

Stroke Prevention ◽

Antihypertensive Drugs ◽

Angiotensin Receptor Blockers ◽

Antihypertensive Agents ◽

Pressure Control ◽

Angiotensin Receptor ◽

Risk Of Death ◽

Pressure Lowering ◽

Receptor Blockers

Hypertension is the most important modifiable risk factor for primary and secondary stroke prevention. All antihypertensive drugs are effective in primary prevention: the risk reduction for stroke is 30—42%. However, not all classes of drugs have the same effects: there is some indication that angiotensin receptor blockers may be superior to other classes of antihypertensive drugs in stroke prevention. Seventy-five percent of patients who present to hospital with acute stroke have elevated blood pressure within the first 24—48 hours. Extremes of systolic blood pressure (SBP) increase the risk of death or dependency. The aim of treatment should be to achieve and maintain the SBP in the range 140—160 mmHg. However, fast and drastic blood pressure lowering can have adverse consequences. The PROGRESS trial of secondary prevention with perindopril + indapamide versus placebo + placebo showed a decrease in numbers of stroke recurrences in patients given both active antihypertensive agents, more impressive for cerebral haemorrhage.There were also indications that active treatment might decrease the development of post-stroke dementia.

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