Aminotriazole, thyroid function, and catecholamines in nephrogenic hypertension in rats

1969 ◽  
Vol 47 (5) ◽  
pp. 407-414 ◽  
Author(s):  
M. J. Fregly ◽  
A. H. Anton
Keyword(s):  
Blood Pressure ◽  
Systolic Blood Pressure ◽  
Adrenal Glands ◽  
Weight Ratio ◽  
Male Rats ◽  
Heart Weight ◽  
Threshold Pressure ◽  
Body Weight Ratio ◽  
Blood Pressures ◽  
Blood Pressure Range

Administration of graded doses of the antithyroid agent aminotriazole (ATZ) to male rats whose kidneys were bilaterally encapsulated with latex envelopes provided protection against the elevation of systolic blood pressure to the level of untreated, renal-encapsulated controls. The doses used were 5, 10, 50, and 250 p.p.m. mixed thoroughly into food. Blood pressures of the groups treated with either 50 or 250 p.p.m. ATZ were within the range of the non-encapsulated controls during the last 7 weeks of the 15-week experiment. Hypothyroidism accompanied administration of the highest dose of ATZ in that heart rate was reduced, and thyroid weight increased, beyond the levels observed for renal-encapsulated control rats. A sigmoid relationship was observed between heart to body weight ratio and systolic blood pressure for all rats. This relationship suggests that heart weight is unaffected by change in blood pressure until the threshold pressure of 150–159 mm Hg is reached. Beyond this threshold pressure, heart weight increased sharply to reach a level approximately 30% above that observed within the blood pressure range of 120–149 mm Hg. Treatment of hypertensive rats with ATZ failed to affect heart and adrenal norepinephrine and adrenal epinephrine concentrations, suggesting a lack of correlation between blood pressure and concentration of these catecholamines in the heart and adrenal glands.

Training and bradycardia in rats

1965 ◽  
Vol 209 (6) ◽  
pp. 1089-1094 ◽  
Author(s):  
Charles M. Tipton
Keyword(s):  
Body Weight ◽  
Weight Ratio ◽  
Experimental Period ◽  
Mature Male ◽  
Male Rats ◽  
Heart Weight ◽  
Body Weight Ratio ◽  
Satisfactory Explanation ◽  
Heart Rates ◽  
Weight Percentage

Bradycardia produced by training was investigated in 228 mature male rats belonging to normal, vagotomized, diencephalon-lesioned, immunological sympathectomized, and hypophysectomized groups. During a 70-day experimental period, resting heart rates of trained unanesthetized rats were significantly lower than those of non-trained rats at approximately 40 days after the training program had been initiated. Resting heart rates were correlated with body weight, wet and dry heart weight, percentage of solids, and the heart weight/body weight ratio (heart ratio). Several coefficients were statistically significant but the majority of the coefficients were below ±0.60 and exhibited a low relationship between the various parameters. Heart ratios for the trained vagotomized, diencephalon-lesioned, and immunological sympathectomized were significantly lower than the ratios from normal trained animals. Similar trends were observed with the nontrained subgroups when these ratios were compared with normal nontrained animals. The only exercising group that exhibited statistical evidence for cardiac hypertrophy was the normal trained group. It was concluded that other aspects beside the weight of the heart must be considered in any satisfactory explanation for this form of bradycardia.

Reversibility of cold-induced hypertension after removal of rats from cold

1990 ◽  
Vol 68 (7) ◽  
pp. 830-835 ◽  
Author(s):  
Orit Shechtman ◽  
Paula E. Papanek ◽  
Melvin J. Fregly
Keyword(s):  
Blood Pressure ◽  
Body Weight ◽  
Cardiac Hypertrophy ◽  
Cold Exposure ◽  
Adrenal Glands ◽  
Treated Group ◽  
Left Ventricular ◽  
Male Rats ◽  
Heart Weight ◽  
Renal Hypertrophy

Chronic exposure of rats to cold air induces hypertension, including elevation of blood pressure and cardiac hypertrophy. The present study was designed to assess reversibility of these changes after removal from cold. Five groups of six male rats each were exposed to cold (5 ± 2 °C) for 39 days, while six control rats were maintained at 26 ± 2 °C. Systolic blood pressures of the rats in one of the cold-treated groups, as well as the controls, were measured twice weekly throughout the experiment. Blood pressure of the cold-exposed rats (150 ± 3 mmHg; 1 mmHg = 133.3 Pa) became elevated significantly above that of controls (129 ± 3 mmHg) within 4 weeks. On day 39 of cold exposure, one group (six rats) of the cold-treated rats was sacrificed while still in the cold. The remaining four groups of cold-treated rats were than removed from cold and kept at 26 ± 2 °C. One group of cold-treated rats was sacrificed weekly thereafter. During the last week, the six control rats were also sacrificed. At death, the heart, kidneys, and adrenal glands were removed and weighed. Mean heart weight of the cold-treated group (346 ± 7 mg/100 g body weight), sacrificed prior to removal from cold, was significantly (p < 0.01) greater than that of controls (268 ± 5 mg/100 g body weight). The increased heart weight of the cold-treated group appeared to result mainly from an increase in left ventricular weight. The weights (mg/100 g body weight) of the kidneys and adrenal glands of cold-treated rats, measured prior to removal from cold, were significantly (p < 0.01) greater than those of controls. Two weeks after removal from cold, blood pressure, heart weight, and left ventricular weight decreased from the levels observed prior to removal from cold. However, they were still significantly greater than those of controls through the fourth week after removal from cold. Thus, the hypertension accompanying a 39-day exposure to cold appears to be only partially reversible at 4 weeks after removal from cold.Key words: cold exposure, hypertension, blood pressure, reversibility of hypertension, renal hypertrophy, cardiac hypertrophy.

Relationship between blood pressure and organ weight in the rat

1962 ◽  
Vol 202 (5) ◽  
pp. 967-970 ◽  
Author(s):  
Melvin J. Fregly
Keyword(s):  
Blood Pressure ◽  
Systolic Blood Pressure ◽  
Pressure Range ◽  
Blood Pressure Level ◽  
Weight Ratio ◽  
Organ Weight ◽  
Systolic Blood Pressure Level ◽  
Blood Pressure Range ◽  
The Relationship ◽  
High Range

A relationship exists between systolic blood pressure and the organ to body weight ratios of heart, thyroid, adrenals, and kidneys. In the cases of heart, thyroid, and adrenals, the relationship is sigmoid in character, with the fast-rising portion of the curve beginning at a systolic blood pressure range of 150–159 mm Hg. Beginning at this same blood pressure range, kidney weight ratio increases linearly with increases in blood pressure. It is of interest that these changes occur at a blood pressure range which is generally considered to lie either at the high range of normotension or the low range of hypertension. The only organ weight ratio apparently unrelated to systolic blood pressure level is that of the testis. Some interrelationships among weight ratios of these organs were observed and are discussed.

Abstract 13798: Ablation of the Hypertension Candidate Gene ATP2B1 Results in Increased Blood Pressure and Cardiac Hypertrophic Remodeling

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Sally K Hammad ◽  
Min Zi ◽  
Sukhpal Prehar ◽  
Robert Little ◽  
Ludwig Neyses ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Cardiac Hypertrophy ◽  
Diastolic Pressure ◽  
Association Studies ◽  
Weight Ratio ◽  
Blood Pressure Regulation ◽  
Heart Weight ◽  
Genome Wide Association Studies ◽  
Pressure Regulation ◽  
The Impact

Introduction: Hypertension is a major risk factor for cardiac hypertrophy and heart failure. Genome wide association studies have recently identified single nucleotide polymorphisms in ATP2B1 , the gene encoding the calcium extrusion pump, plasma membrane calcium ATPase (PMCA1), as having a strong association with hypertension risk. Hypothesis: PMCA1 plays an important role in regulation of blood pressure and protection against hypertension and cardiac hypertrophy. Aims: We aim to examine whether there is a functional link between PMCA1 and blood pressure regulation, and the development of hypertension. And to determine the impact this link may have on cardiac structure and function. Methods and Results: To study the role of PMCA1 we generated a global PMCA1 heterozygous knockout mouse (PMCA1 Ht ). PMCA1 Ht mice had 46% to 52% reduction in PMCA1 protein expression compared to the WT, in aorta, heart, kidney and brain. To study the mice under hypertensive stress conditions, 3 month old PMCA1 Ht and wild type (WT) mice were infused via minipump with angiotensin II (1mg/Kg/daily) or water as a control. Upon angiotensin treatment, PMCA1 Ht mice showed a significantly greater increase in systolic (62.24±3.05 mmHg) and diastolic pressure (52.68±4.67 mmHg), in comparison to the WT (33.37±2.91 mmHg and 23.94±4.56 mmHg, respectively), P<0.001, n=12. Moreover, PMCA1 Ht mice showed a significantly greater hypertrophic response as indicated by a greater heart weight to tibia length ratio, cardiomyocyte cell size (410±18.7 μm 2 ), compared to WT mice (340.4±9.8 μm 2 ), and increased expression of B-type natriuretic peptide (BNP), 2.36 ± 0.25 fold change, n =5-6, P< 0.01. Echocardiography showed no significant changes between PMCA1 Ht and WT mice, in heart rate, and in cardiac function, as indicated by fractional shortening and ejection fraction. In addition, PMCA1 Ht mice showed no sign of lung congestion as indicated by lung weight to body weight ratio. Conclusion: ATP2B1 deletion leads to increased blood pressure and cardiac hypertrophy. This provides functional evidence that PMCA1 is involved in blood pressure regulation and protects against the development of hypertension and cardiac hypertrophy.

scholarly journals Acute Hemodynamic Changes Associated with Zumba and ZOCA Dance Exercises among Females of Selected Gyms in Lusaka, Zambia

2020 ◽  
Vol 2 (1) ◽  
pp. 84-91
Author(s):  
Chanda Grace Chisunka ◽  
◽  
Gibson Sijumbila ◽  
Fastone Goma ◽  
◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Systolic Blood Pressure ◽  
Hemodynamic Changes ◽  
Aerobic Dance ◽  
Arterial Blood ◽  
Effective Dynamic ◽  
Blood Pressure Monitors ◽  
Blood Pressures

Background: Dynamic exercises are known to elicit hemodynamic changes such as an increase in arterial blood pressure and heart rate. Zumba and ZOCA are part of a fast growing group of dance fitness programmes designed to provide a cardiovascular dynamic workout. Despite their growing popularity, very few studies have been done to provide knowledge regarding the hemodynamic changes associated with these exercises. Methods: Case study in which 27 females took part in either a Zumba or ZOCA class. Using digital blood pressure monitors, recordings of blood pressure and heart rate were taken, firstly, before commencement of the exercise, secondly, after 30 minutes after exercise and thirdly, at the end of the class.Results: Mean baseline blood pressures were 118 (SD = 14) mmHg and 77 (SD = 7) mmHg, systolic and diastolic blood pressures, respectively. After 30 minutes of dancing, mean systolic blood pressure increased to 130 (SD = 19) mmHg (p˂ 0.05) while diastolic blood pressureonly rose to an average of 80 (SD = 8) mmHg (p˃ 0.05). At the end of the class (after the cool down phase) mean systolic blood pressure reduced to 109 (SD = 13) mmHg (p˂0.05) while diastolic blood pressure reduced to 74(SD = 12) mmHg (p˂ 0.05). Conclusions: Zumba and ZOCA elicited significant hemodynamic changes that can be attributed to these exercises stimulating the cardiovascular regulatory mechanisms (e.g central command and exercise-pressor) sufficiently and hence resulting in autonomic adjustmentsthat were concurrent with effective dynamic exercise. Keywords: Blood Pressure, Heart Rate, Aerobic, Dance Exercise

Abstract 670: Immediate And Sustained Blood Pressure Lowering by CRF-receptor Stimulation: A Novel Approach To Antihypertensive Therapy?

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Thomas Dieterle ◽  
Silvia Meili-Butz ◽  
Katrin Buehler ◽  
Christian Morandi ◽  
Dietlinde John ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Body Weight ◽  
Arterial Hypertension ◽  
Weight Ratio ◽  
Chronic Administration ◽  
Cardiovascular Responses ◽  
High Salt ◽  
Heart Weight ◽  
Receptor Stimulation ◽  
Novel Approach

Background: Recently, novel corticotropin-releasing factor (CRF)-related peptides, named urocortin I (UcnI), UcnII, and UcnIII were described. Available data suggest that the Ucns are part of a peripheral CRF system modulating cardiovascular function and mediating cardiovascular responses to stress. Blood pressure (BP) lowering effects have been described after administration of UcnI. However, no data are available on effects of UcnII on BP in an animal model of systemic arterial hypertension. Methods: Experiments were performed in Dahl salt-sensitive (DSS) and salt-resistant rats (DSR, control). Animals were fed a diet containing 4% NaCl (high salt) to induce arterial hypertension in DSS rats. At the end of week 2 of high salt diet, both DSS and DSR rats were randomly assigned to i.p. injections of either UcnII (2.5 μg/kg body weight) or vehicle b.i.d. for five weeks. Animals underwent repetitive tail cuff BP measurements at baseline (prior to first injection), at 5 and 15 minutes after the first injection and at week 1, 2, and 5 of b.i.d. treatment. At week 5 animals were sacrificed to determine heart weight /body weight ratio. Results: Systolic BP (SBP, mmHg) and heart rate (HR, min −1 ) are given in the following table as mean ± SD (n=10 per group). Conclusions: In hypertensive DSS rats, acute CRF-receptor stimulation by UcnII immediately lowered BP to the range observed in DSR rats. Compared to vehicle-treated DSS rats, sustained BP reduction was observed with further chronic administration of UcnII. No severe reflex tachycardia was observed after administration of UcnII. Thus, CRF-receptor stimulation might represent a novel approach to the treatment of arterial hypertension.

Abstract 507: Dual AT1 Receptor/Neprilysin (NEP) Inhibition (ARNI) vs. AT1 Receptor Blockade in TGR(mRen2)27 Rats: The More NEP Inhibition The Better?

Hypertension ◽  
2014 ◽  
Vol 64 (suppl_1) ◽  
Author(s):  
Lodi C Roksnoer ◽  
Joep H van Esch ◽  
Richard van Veghel ◽  
Ingrid M Garrelds ◽  
Usha M Bhaggoe ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Vascular Reactivity ◽  
Weight Ratio ◽  
At1 Receptor ◽  
Mesenteric Arteries ◽  
Heart Weight ◽  
Sodium Reabsorption ◽  
High Dose ◽  
Arterial Blood ◽  
Nep Inhibition

Objective: Neprilysin inhibitors (NEPi) prevent the breakdown of natriuretic peptides, promoting vasodilation and natriuresis. However, they also increase angiotensin and endothelin-1 (ET1). This study compared the combination of an AT1 receptor antagonist (irbesartan, IRB) ± a low or a high dose of the NEPi thiorphan in renin-overexpressing, hypertensive TGR(mREN2)27 rats. Methods: TGR(mREN2)27 rats were treated for three weeks with vehicle, IRB (15 mg/kg.day) or IRB + thiorphan (0.1 or 1.0 mg/kg.day; TH0.1 and TH1.0). Hemodynamics were evaluated by telemetry, and vascular reactivity was determined in isolated mesenteric arteries (Mulvany myograph). Results: Baseline mean arterial blood pressure (MAP) was 168±3 mmHg. All treatments lowered MAP by ≈50 mmHg around day 4. After 7 days, MAP started to increase during treatment with IRB or IRB+TH1.0 (to 141±10 mmHg and 133±10 mmHg, respectively, on day 21), while MAP in rats treated with IRB+TH0.1 remained low at 104±5 mmHg on day 21. Heart weight/body weight ratio, cardiac ANP expression and myocyte size decreased only in the IRB+TH0.1 group. Plasma ET1 was increased only by TH1.0 versus IRB alone, and this increase was accompanied by an increase in renal sodium-hydrogen exchanger 3 (NHE3) protein expression: ET1-induced constriction was reduced by IRB+TH0.1 only. Vascular ET B R expression levels and studies with the ET1 type B receptor (ET B R) antagonist BQ788 revealed that this reduction was most likely due to ET B R upregulation. Conclusion: TH0.1 enhanced the blood pressure-lowering effects of irbesartan and diminished cardiac hypertrophy. Higher doses of thiorphan resulted in significant ET1 rises and renal NHE3 upregulation, thereby increasing blood pressure and sodium reabsorption. The simultaneously occurring upregulation of vasodilatory ET B R was insufficient to overcome this effect. Clearly therefore, too much NEPi on top of AT1 receptor antagonism might be harmful.

THE BLOOD PRESSURE OF NEWBORN INFANTS: INDIRECT DETERMINATION BY AN AUTOMATIC BLOOD PRESSURE RECORDER IN 20 INFANTS

PEDIATRICS ◽  
1960 ◽  
Vol 25 (1) ◽  
pp. 50-53
Author(s):  
Robert L. Morse ◽  
Gordon L. Brownell ◽  
James H. Currens
Keyword(s):  
Blood Pressure ◽  
Systolic Blood Pressure ◽  
Diastolic Blood Pressure ◽  
Newborn Infants ◽  
Indirect Determination ◽  
Pressure Recording ◽  
Automatic Blood Pressure ◽  
Blood Pressures ◽  
The Mean ◽  
Blood Pressure Recording

Systolic and diastolic blood pressures have been determined in 20 infants by the use of an automatic blood pressure-recording machine. The mean systolic blood pressure was 7.1 cm Hg (range 5.8 to 9.5). The mean diastolic blood pressure was 5.2 cm Hg (range 4.2 to 6.4).

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