scholarly journals Angiotensinogen and the Modulation of Blood Pressure

2021 ◽  
Vol 8 ◽  
Author(s):  
Zimei Shu ◽  
Jiahui Wan ◽  
Randy J. Read ◽  
Robin W. Carrell ◽  
Aiwu Zhou

The angiotensin peptides that control blood pressure are released from the non-inhibitory plasma serpin, angiotensinogen, on cleavage of its extended N-terminal tail by the specific aspartyl-protease, renin. Angiotensinogen had previously been assumed to be a passive substrate, but we describe here how recent studies reveal an inherent conformational mechanism that is critical to the cleavage and release of the angiotensin peptides and consequently to the control of blood pressure. A series of crystallographic structures of angiotensinogen and its derivative forms, together with its complexes with renin show in molecular detail how the interaction with renin triggers a profound shift of the amino-terminal tail of angiotensinogen with modulation occurring at several levels. The tail of angiotensinogen is restrained by a labile disulfide bond, with changes in its redox status affecting angiotensin release, as demonstrably so in the hypertensive complication of pregnancy, pre-eclampsia. The shift of the tail also enhances the binding of renin through a tail-in-mouth allosteric mechanism. The N-terminus is now seen to insert into a pocket equivalent to the hormone-binding site on other serpins, with helix H of angiotensinogen unwinding to form key interactions with renin. The findings explain the precise species specificity of the interaction with renin and with variant carbohydrate linkages. Overall, the studies provide new insights into the physiological regulation of angiotensin release, with an ability to respond to local tissue and temperature changes, and with the opening of strategies for the development of novel agents for the treatment of hypertension.

Author(s):  
Niken Setyaningrum ◽  
Andri Setyorini ◽  
Fachruddin Tri Fitrianta

ABSTRACTBackground: Hypertension is one of the most common diseases, because this disease is suffered byboth men and women, as well as adults and young people. Treatment of hypertension does not onlyrely on medications from the doctor or regulate diet alone, but it is also important to make our bodyalways relaxed. Laughter can help to control blood pressure by reducing endocrine stress andcreating a relaxed condition to deal with relaxation.Objective: The general objective of the study was to determine the effect of laughter therapy ondecreasing elderly blood pressure in UPT Panti Wredha Budhi Dharma Yogyakarta.Methods: The design used in this study is a pre-experimental design study with one group pre-posttestresearch design where there is no control group (comparison). The population in this study wereelderly aged over> 60 years at 55 UPT Panti Wredha Budhi Dharma Yogyakarta. The method oftaking in this study uses total sampling. The sample in this study were 55 elderly. Data analysis wasused to determine the difference in blood pressure before and after laughing therapy with a ratio datascale that was using Pairs T-TestResult: There is an effect of laughing therapy on blood pressure in the elderly at UPT Panti WredhaBudhi Dharma Yogyakarta marked with a significant value of 0.000 (P <0.05)


2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Livia Beatriz Santos Limonta ◽  
Letícia dos Santos Valandro ◽  
Flávio Gobis Shiraishi ◽  
Pasqual Barretti ◽  
Roberto Jorge da Silva Franco ◽  
...  

Resistant hypertension (RH) is characterized by blood pressure above 140 × 90 mm Hg, despite the use, in appropriate doses, of three antihypertensive drug classes, including a diuretic, or the need of four classes to control blood pressure. Resistant hypertension patients are under a greater risk of presenting secondary causes of hypertension and may be benefited by therapeutical approach for this diagnosis. However, the RH is currently little studied, and more knowledge of this clinical condition is necessary. In addition, few studies had evaluated this issue in emergent countries. Therefore, we proposed the analysis of specific causes of RH by using a standardized protocol in Brazilian patients diagnosed in a center for the evaluation and treatment of hypertension. The management of these patients was conducted with the application of a preformulated protocol which aimed at the identification of the causes of resistant hypertension in each patient through management standardization. The data obtained suggest that among patients with resistant hypertension there is a higher prevalence of secondary hypertension, than that observed in general hypertensive ones and a higher prevalence of sleep apnea as well. But there are a predominance of obesity, noncompliance with diet, and frequent use of hypertensive drugs. These latter factors are likely approachable at primary level health care, since that detailed anamneses directed to the causes of resistant hypertension are applied.


2013 ◽  
Vol 154 (6) ◽  
pp. 203-208 ◽  
Author(s):  
Gábor Simonyi ◽  
J. Róbert Bedros ◽  
Mihály Medvegy

It is well known that hypertension is an independent cardiovascular risk factor. Treatment of hypertension frequently includes administration of three or more drugs. Resistant hypertension is defined when blood pressure remains above target value despite full doses (the patient’s maximum tolerated dose) of antihypertensive medication consisting of at least three different classes of drugs including a diuretic. Pharmacological treatment of hypertension is often unsuccessful despite the increasing number of drug combinations. Uncontrolled hypertension, however, increases the cardiovascular risk. Device treatment of resistant hypertension is currently testing two major fields. One of them the stimulation of baroreceptors in the carotid sinus and the other is radiofrequency ablation of sympathetic nerve fibers around renal arteries to reduce blood pressure in drug resistant hypertension. Orv. Hetil., 2013, 154, 203–208.


Hypertension ◽  
2021 ◽  
Vol 78 (Suppl_1) ◽  
Author(s):  
Pawan Acharya ◽  
Sweta Koirala ◽  
Pabitra Babu Soti ◽  
Sneha Sharma ◽  
Abhishek Sapkota ◽  
...  

Background: May Measurement Month (MMM) 2020 was not officially executed globally due to the COVID-19 pandemic. But in Nepal, the MMM 2020 was conducted by following COVID-19 safety measures. Methods: We used an opportunistic screening campaign for blood pressure measurement among individuals ≥18 years in Nepal. Of the three measurements, the second and third measurements were used to estimate the mean systolic and diastolic blood pressure(BP). We defined hypertension as the systolic BP ≥ 120 or diastolic BP≥90 mmHg and or currently taking antihypertensive medicine. Results: Among the total 11,486 participants, 57%(6568/11486) were females. The mean age of the screenees was 45years(SD=17.0). The mean systolic and diastolic BP were 125.8(SD= 18.0) and 81.6(SD=10.5) respectively. About 31.3%(3592/11481) participants had hypertension. Among the hypertensive persons, 40.2%(1444/3592) were aware of their hypertension status. Among these who were aware, 79.4%(1146/1444) were taking antihypertensive medicine. However, the overall proportion of hypertensive patients taking medicine was 32.0%(1146/3592). The BP was controlled among 46% ( 527/1444) of participants who were under medication. Logistic regression analysis adjusting age, sex, body mass index(BMI), and smoking status found males, higher age groups, higher BMI, and smokers had higher odds of being hypertensive. (Figure 1) Conclusion: The results suggest a need to address the gap in awareness, diagnosis, and treatment of hypertension in Nepal. The results are limited due to the non-random participation of screenees. Figure 1. Odds ratio plot


PEDIATRICS ◽  
1963 ◽  
Vol 32 (4) ◽  
pp. 691-702
Author(s):  
Sid Robinson

The central body temperature of a man rises gradually during the first half hour of a period of work to a higher level and this level is precisely maintained until the work is stopped; body temperature then slowly declines to the usual resting level. During prolonged work the temperature regulatory center in the hypothalamus appears to be reset at a level which is proportional to the intensity of the work and this setting is independent of environmental temperature changes ranging from cold to moderately warm. In hot environments the resistance to heat loss may be so great that all of the increased metabolic heat of work cannot be dissipated and the man's central temperature will rise above the thermostatic setting. If this condition of imbalance is continued long enough heat stroke will ensue. We have found that in a 3 mile race lasting only 14 minutes on a hot summer day a runner's rectal temperature may rise to 41.1°C., with heat stroke imminent. The physiological regulation of body temperature of men in warm environments and during the increased metabolic heat production of work is dependent on sweating to provide evaporative cooling of the skin, and on adjustments of cutaneous blood flow which determine the conductance of heat from the deeper tissues to the skin. The mechanisms of regulating these responses during work are complex and not entirely understood. Recent experiments carried out in this laboratory indicate that during work, sweating may be regulated by reflexes originating from thermal receptors in the veins draining warm blood from the muscles, summated with reflexes from the cutaneous thermal receptors, both acting through the hypothalamic center, the activity of which is increased in proportion to its own temperature. At the beginning of work the demand for blood flow to the muscles results in reflex vasoconstriction in the skin. As the body temperature rises the thermal demand predominates and the cutaneous vessels dilate, increasing heat conductance to the skin. Large increments in cardiac output and compensatory vasoconstriction in the abdominal viscera make these vascular adjustments in work possible without circulatory embarrassment.


PEDIATRICS ◽  
1989 ◽  
Vol 83 (6) ◽  
pp. 1076-1076
Author(s):  
VIVIAN REZNIK ◽  
WILLIAM GRISWOLD ◽  
STANLEY MENDOZA

Angiotensin-converting enzyme inhibitors are effective at lowering blood pressure in the neonate and the child. However, these drugs, when used for the treatment of hypertension in the premature infant, must be used with caution to avoid the complications that are well documented in the literature. All of the infants described in the article by Perlman and Volpe had extreme hypotension and oligunia. A group of nine infants with renal failure complicating captopril therapy were recently reported from the same institution.


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