Thyroid Function and Blood Pressure in Two New Strains of Spontaneously Hypertensive and Normotensive Rats

1978 ◽  
Vol 54 (4) ◽  
pp. 391-395
Author(s):  
M. Vincent ◽  
H. Bornet ◽  
F. Berthezene ◽  
J. Dupont ◽  
J. Sassard
Keyword(s):  
Blood Pressure ◽  
Body Weight ◽  
Oral Administration ◽  
Systolic Blood Pressure ◽  
Thyroid Function ◽  
Total Plasma ◽  
Spontaneously Hypertensive ◽  
Free T3 ◽  
The Difference

1. The influence of thyroid function on the development of hypertension was studied in strains of spontaneously hypertensive (SH) and normotensive rats. 2. Surgical thyroidectomy decreased systolic blood pressure more markedly in SH rats than in normotensive rats. The effects of oral administration of 5 and 100 μg of thyroxine 24 h—1 100 g—1 were studied in the thyroidectomized animals. In the two strains the blood pressure returned to control levels only after administration of the larger dose. 3. The evolution of body weight, total plasma tri-iodothyronine (T3) and tetraiodothyronine (T4) concentrations were followed as a function of age in SH rats and normotensive rats from 5 to 21 weeks. At each age, SH rats showed significantly larger body weight and decreased T4 concentrations. Plasma T3 in SH rats was lower than in normotensive rats until 15 weeks of age, after which the difference was not significant. At 11 weeks, plasma free T3 and T4 concentrations were slightly lower in SH rats than in normotensive rats. 4. The more marked hypotensive effects of surgical thyroidectomy in SH rats cannot be related to increased thyroid function.

scholarly journals Effects of Valsartan vs Amlodipin on renal function in salt loaded spontaneously hypertensive rats

2014 ◽  
Vol 60 (01) ◽  
pp. 53-59
Author(s):  
Kalina Gjorgjievska ◽  
Dimce Zafirov ◽  
Maja Jurhar Pavlova ◽  
Svetlana Cekovska
Keyword(s):  
Blood Pressure ◽  
Renal Function ◽  
Body Weight ◽  
Systolic Blood Pressure ◽  
Spontaneously Hypertensive Rats ◽  
Treated Group ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Treatment Groups ◽  
Renal Function Tests

The goal of this study was to compare the effects of valsartan and amlodipin on the systolic blood pressure and parameters specific to the renal function in salt loaded spontaneously hypertensive rats (SHR). 32 male SHR were used at age of 20 weeks and body weight ranging between 265-300 g. From 8 weeks of age tab water was replaced with a solution of NaCl (1%) given ad libitum. Rats were divided into 2 groups: valsartan treated group SHRVAL (n=16) in which valsartan was given at a dose of 10 mg/kg b. w. and amlodipine treated group SHRAMLO (n=16) in which amlodipine was given at a dose of 5 mg/kg b. w. For a period of 12 weeks we have evaluated the effect of the investigated drugs on systolic blood pressure, body weight and renal function tests. In salt loaded rats amlodipine was more effective in reducing the systolic blood pressure in contrast to valsartan who had more pronounced effect on renal parameters most evident in proteinuria. Since both treatment groups have different mechanism of action a combination therapy may be beneficial in improving renal function in SHR rats.

scholarly journals Effect of Age and Body Weight on the Systolic Blood Pressure of the Growing Chicken

1963 ◽  
Vol 42 (6) ◽  
pp. 1465-1466 ◽  
Author(s):  
E.L. Nichols ◽  
D.K. Hotchkiss ◽  
S.L. Balloun
Keyword(s):  
Blood Pressure ◽  
Body Weight ◽  
Systolic Blood Pressure ◽  
Effect Of Age

Metformin decreases plasma insulin levels and systolic blood pressure in spontaneously hypertensive rats

1994 ◽  
Vol 267 (4) ◽  
pp. H1250-H1253 ◽  
Author(s):  
S. Verma ◽  
S. Bhanot ◽  
J. H. McNeill
Keyword(s):  
Blood Pressure ◽  
Systolic Blood Pressure ◽  
Spontaneously Hypertensive Rats ◽  
Plasma Insulin ◽  
Metformin Treatment ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Insulin Levels ◽  
Plasma Insulin Levels ◽  
Wistar Kyoto

To determine the relationship between hyperinsulinemia and hypertension in spontaneously hypertensive rats (SHR), the antihyperglycemic agent metformin was administered to SHR and their Wistar-Kyoto (WKY) controls, and its effects on plasma insulin levels and blood pressure were examined. Five-week-old rats were started on oral metformin treatment (350 mg.kg-1.day-1, which was gradually increased to 500 mg.kg-1.day-1 over a 2-wk period). Metformin treatment caused sustained decreases in plasma insulin levels in the SHR (27.1 +/- 2.3 vs. untreated SHR 53.5 +/- 2.7 microU/ml, P < 0.001) without having any effect in the WKY (30.7 +/- 2.2 vs. untreated WKY 37.8 +/- 1.6 microU/ml, P > 0.05). The treatment did not affect the plasma glucose levels in any group. Metformin treatment also attenuated the increase in systolic blood pressure in the SHR (157 +/- 6.0 vs. untreated SHR 196 +/- 9.0 mmHg, P < 0.001) but had no effect in the WKY (134 +/- 3 vs. untreated WKY 136 +/- 4 mmHg, P > 0.05). Furthermore, raising plasma insulin levels in the metformin-treated SHR to levels that existed in the untreated SHR reversed the effect of metformin on blood pressure (189 +/- 3 vs. untreated SHR 208 +/- 5.0 mmHg, P > 0.05). These findings suggest that either hyperinsulinemia may contribute toward the increase in blood pressure in the SHR or that the underlying mechanism is closely associated with the expression of both these disorders.

Lack of influence of the antidopaminergic drug domperidone on basal and TRH-stimulated TSH-serum levels after oral administration

1982 ◽  
Vol 101 (4) ◽  
pp. 550-554 ◽  
Author(s):  
K. W. Wenzel ◽  
J. Döring
Keyword(s):  
Oral Administration ◽  
Thyroid Function ◽  
Oral Absorption ◽  
Statistical Significance ◽  
Oral Intake ◽  
Serum Levels ◽  
The Novel ◽  
Antiemetic Drug ◽  
First Pass ◽  
The Difference

Abstract. Since antidopaminergic drugs are known to elevate basal and TRH-stimulated TSH-serum levels and since this effect was also shown after iv administration of the novel dopamine antagonistic agent domperidone, it was investigated, whether this antiemetic drug could interfere after oral intake with the evaluation of thyroid function. Oral domperidone caused a marked TSH-enhancement of TRH-induced TSH increments in 6 out of 14 euthyroid subjects, with no statistical significance, however. The difference between oral and parenteral influence as well as inter-individual changes are probably due to the varying first pass effect of the drug after oral absorption.

Hypoxic pressor response, cardiac size, and natriuretic peptides are modified by long-term intermittent hypoxia

1999 ◽  
Vol 87 (6) ◽  
pp. 2025-2031 ◽  
Author(s):  
Holger Kraiczi ◽  
Jarkko Magga ◽  
Xiang Ying Sun ◽  
Heikki Ruskoaho ◽  
Xiaohe Zhao ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Body Weight ◽  
Atrial Natriuretic Peptide ◽  
Right Ventricular ◽  
Natriuretic Peptide ◽  
Intermittent Hypoxia ◽  
Spontaneously Hypertensive ◽  
Wistar Kyoto

We investigated whether the effect of long-term intermittent hypoxia (LTIH) on cardiovascular function may be modified by preexisting genetic traits. To induce LTIH experimentally, cycles of 90-s hypoxia (nadir 6%) followed by 90-s normoxia were applied to six Wistar-Kyoto and six spontaneously hypertensive rats during 8 h daily. Comparison with the same number of control animals after 70 days revealed no alteration of intra-arterial blood pressure or heart rate. Blood pressure responsiveness to a brief hypoxic stimulus was enhanced in the LTIH animals, regardless of strain, whereas the hypoxia-induced increase in heart rate was abolished. In the spontaneously hypertensive but not the Wistar-Kyoto rats, LTIH increased left ventricular weight-to-body weight ratio and content of atrial natriuretic peptide mRNA. Expression of B-type natriuretic peptide was unchanged (Northern blot). Slightly increased right ventricular weight-to-body weight ratios in the LTIH animals were associated with higher right ventricular atrial natriuretic peptide and B-type natriuretic peptide mRNA amounts. Consequently, the effects of LTIH on different components of cardiovascular function appear incompletely related to each other and differentially influenced by constitutional traits.

Contribution of vasopressin to the maintenance of blood pressure during dehydration

1983 ◽  
Vol 245 (5) ◽  
pp. F615-F621 ◽  
Author(s):  
R. L. Woods ◽  
C. I. Johnston
Keyword(s):  
Blood Pressure ◽  
Body Weight ◽  
Systolic Blood Pressure ◽  
Arginine Vasopressin ◽  
Cardiovascular Response ◽  
Urine Volume ◽  
Brattleboro Rats ◽  
Continuous Administration ◽  
Plasma Vasopressin ◽  
Long Evans

Normal Long-Evans rats, when dehydrated for up to 72 h, have a progressive rise in plasma vasopressin that is associated with a fall in body weight and urine volume, a rise in plasma and urine osmolality, and the maintenance of normal systolic blood pressure. In contrast, Brattleboro diabetes insipidus rats, genetically deficient in vasopressin, when dehydrated to achieve an equivalent body weight loss, have a significant 15 mmHg fall in systolic blood pressure. Even when fluid balance is corrected in the Brattleboro rats by the continuous administration of 1-desamino-8-D-arginine vasopressin, a synthetic vasopressin analogue with potent antidiuretic properties but minimal pressor activity, blood pressure still falls when the animals are dehydrated. In contrast, Brattleboro rats infused with exogenous arginine vasopressin to produce a plasma vasopressin level of 18.9 +/- 3.5 pg X ml-1 are able to maintain normal blood pressure during 48 h of dehydration. This level of vasopressin is comparable to the level found endogenously in dehydrated Long-Evans rats and is nonpressor in normal rats. These results suggest that both the antidiuretic and vasoconstrictor properties of vasopressin are important in the cardiovascular response to dehydration.

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