Age-Dependent Changes of Plasma Renin Concentration in Humans

1973 ◽  
Vol 45 (s1) ◽  
pp. 273s-278s ◽  
Author(s):  
K. Hayduk ◽  
D. K. Krause ◽  
W. Kaufmann ◽  
R. Huenges ◽  
U. Schillmöller ◽  
...  
Keyword(s):  
Sodium Intake ◽  
Post Partum ◽  
Age Groups ◽  
Plasma Renin ◽  
Relative Increase ◽  
Upright Posture ◽  
Healthy Children ◽  
Absolute Increase ◽  
Plasma Renin Concentration ◽  
The Mean

1. Plasma renin concentration (PRC) in newborns greatly exceeded PRC in children and adults. PRC in cord plasma of newborns was higher than peripheral venous PRC in their mothers. PRC in the newborns increased further in the first 48 h post partum and then gradually decreased. 2. The mean PRC of healthy children and adults on free sodium intake decreased with age by an exponential function. 3. The absolute increase of PRC in response to upright posture (PRCupright — PRCrecumbent) decreased with age. The relative increase of PRC in response to upright posture (PRCuprjght:PRCrecumbent) remained unchanged with age, the PRC in upright posture being about twice the basal PRC in all age groups.

Dietary chloride modifies renin release in normal humans

1981 ◽  
Vol 241 (4) ◽  
pp. F361-F363 ◽  
Author(s):  
R. J. Koletsky ◽  
R. G. Dluhy ◽  
R. G. Cheron ◽  
G. H. Williams
Keyword(s):  
Sodium Intake ◽  
Plasma Renin ◽  
Normal Subjects ◽  
Renin Release ◽  
Upright Posture ◽  
Ang Ii ◽  
Low Salt ◽  
Normal Humans ◽  
The Mean ◽  
Induced Changes

The effect of high and low chloride diets on the responses of plasma renin activity (PRA), angiotensin II (ANG II), and aldosterone (Aldo) to upright posture was studied in the same normal subjects in balance on constant sodium intake. Diet 1 consisted of 10 meq Na/day (low Na) and either 50 or 150 meq Cl/day. Diet 2 consisted of 200 meq Na/day (high Na) and either 20 or 200 meq Cl/day. The mean recumbent PRA level on the high Na-high Cl diet tended to be lower than on the high Na-low Cl diet but was not significantly different. However, the absolute peak upright PRA levels, 8.8 +/- 1.0 vs. 4.4 +/- 0.8 ng . ml-1 . h-1, and the incremental difference (delta PRA) between recumbent and peak upright PRA levels, 5.5 +/- 0.8 vs. 2.2 +/- 0.5 ng . ml-1 . h-1, were significantly less on the high Na-high Cl diet compared with the high Na-low Cl diet. Similar significant changes were seen in ANG II and Aldo levels. However, there were no significant changes in PRA, ANG II, and Aldo responses to upright posture on the low Na diet when the dietary Cl was varied. It is concluded that dietary Cl is another factor modifying renin release. However, Cl is probably less important than Na because Cl-induced changes in PRA were not seen in the low salt state.

Comparison of the Renin Response to Dopamine and Noradrenaline in Normal Subjects and Patients with Autonomic Insufficiency

1974 ◽  
Vol 46 (4) ◽  
pp. 481-488 ◽  
Author(s):  
C. S. Wilcox ◽  
M. J. Aminoff ◽  
A. B. Kurtz ◽  
J. D. H. Slater
Keyword(s):  
Autonomic Failure ◽  
Sodium Intake ◽  
Plasma Renin ◽  
Normal Subjects ◽  
Control Groups ◽  
Autonomic Reflexes ◽  
Fractional Increase ◽  
The Mean ◽  
Autonomic Insufficiency ◽  
Stimulation Of

1. The effect on plasma renin activity (PRA) of dopamine and noradrenaline infusions was studied in three patients with Shy—Drager syndrome, three patients with Parkinson's disease and normal autonomic reflexes, and three healthy volunteers. The patients with the Shy—Drager syndrome had functional evidence of a peripheral lesion of the sympathetic nervous system and subnormal PRA on a controlled sodium intake. 2. In all subjects catecholamines were infused step-wise for 4 min until a 30% rise in systolic blood pressure occurred. 3. In each subject, PRA fell after noradrenaline but rose after dopamine. The mean fractional increase in PRA after dopamine was no less in the Shy—Drager patients than in the control groups. 4. The results suggest, first, that stimulation of dopamine receptors can release renin, and secondly, that inadequate renin stores cannot explain the low PRA found in our patients with autonomic failure.

URINARY CATECHOLAMINE EXCRETION BY HEALTHY CHILDREN

PEDIATRICS ◽  
1967 ◽  
Vol 39 (2) ◽  
pp. 252-257
Author(s):  
Mary L. Voorhess
Keyword(s):  
Urinary Excretion ◽  
Surface Area ◽  
Body Surface Area ◽  
Body Surface ◽  
Age Groups ◽  
Healthy Children ◽  
Urinary Catecholamine ◽  
Catecholamine Excretion ◽  
Daily Output ◽  
The Mean

There is increase in the daily urinary excretion of dopamine (DA), norepinephrine (NE), epinephrine (E), and 3-methoxy-4-hydroxymandelic acid (VMA) with age. The mean output in micrograms per 24 hours for various age groups is as follows: birth to 1 year-DA 60.9 (± 24.3), NE 10.6 (± 3.4), E 1.3 (± 1.2), VMA 569 (± 309); 1 through 5 years—DA 124.1 (± 40.7), NE (18.8 ± 7.0), E 3.2 (± 2.7), VMA 1348 (± 433); 6 through 15 years—DA 169.3 (± 72.6), NE 37.4 (± 16.6), E 4.8 (± 2.4), VMA 2373 (± 698); over 15 years—DA 249.1 (± 74.9), NE 50.7 (± 15.7), E 7.1 (± 3.3), VMA 3192 (± 699). The studies suggest that the daily output of these compounds in the various age groups is similar when related to body surface area after infancy.

Longitudinal study of platelet angiotensin II binding in human pregnancy

1992 ◽  
Vol 82 (4) ◽  
pp. 377-381 ◽  
Author(s):  
Philip N. Baker ◽  
Fiona Broughton Pipkin ◽  
E. Malcolm Symonds
Keyword(s):  
Longitudinal Study ◽  
Angiotensin Ii ◽  
Post Partum ◽  
Renin Angiotensin System ◽  
Plasma Renin ◽  
Significant Rise ◽  
Renin Substrate ◽  
Plasma Renin Concentration ◽  
Plasma Angiotensin ◽  
In Pregnancy

1. Platelet angiotensin II binding, circulating angiotensin II levels, plasma renin substrate and plasma renin concentration were measured in a longitudinal study of 30 women during pregnancy and the puerperium. 2. There was a significant fall in platelet angiotensin II binding from 11 weeks gestation to 18 weeks gestation (P < 0.01). There were no further significant changes in platelet angiotensin II binding until after delivery, a significant rise in platelet angiotensin II binding being found at 6 weeks post partum as compared with at 36 weeks gestation (P < 0.01). There was no further significant change from 6 to 12 weeks post partum, and platelet angiotensin II binding at 6 and 12 weeks post partum in the pregnant cohort approximated to that in non-pregnant women. These changes parallel those known to occur in pressor responsiveness to angiotensin II in pregnancy. 3. Plasma angiotensin II concentration, plasma renin substrate and plasma renin concentration were all significantly higher during pregnancy than in the puerperium (P < 0.001). There were no significant changes during pregnancy in plasma angiotensin II concentration or plasma renin concentration, although plasma renin substrate rose throughout. 4. Significant inverse correlations between platelet angiotensin II binding and plasma angiotensin II concentration (P < 0.01), plasma renin substrate (P < 0.01) and plasma renin concentration (P 0>001) were found during pregnancy. These data suggest that down-regulation of platelet angiotensin II binding by the components of the renin-angiotensin system pertains in pregnancy. 5. We are currently investigating parallelism between platelet and vascular angiotensin-binding sites. If such is confirmed, studies of platelet angiotensin II binding in pregnancy may be of both basic physiological and clinical interest in relation to the hypertensive diseases of pregnancy.

Late-onset renal hypertension in old rats alters myocardial microvessels

1990 ◽  
Vol 259 (6) ◽  
pp. H1681-H1687 ◽  
Author(s):  
R. J. Tomanek ◽  
M. R. Aydelotte ◽  
C. A. Butters
Keyword(s):  
Late Onset ◽  
Renal Hypertension ◽  
Age Groups ◽  
Left Ventricular ◽  
Numerical Density ◽  
Middle Aged ◽  
Absolute Increase ◽  
The Mean ◽  
Microvascular Alterations ◽  
O2 Supply

We tested the hypothesis that late-onset hypertension in middle-aged (15 mo) and senescent (24 mo) rats would adversely affect the coronary microvasculature. Morphometric analyses were performed on coronary capillaries and arterioles from rats with one-kidney, figure-8 renal wrap hypertension of 3-mo duration. Compared with control rats, wall-to-lumen ratios of arterioles with lumen diameters less than 25 microns were higher in the two hypertensive groups by approximately 30%; larger arterioles did not show consistent intergroup differences. A comparison of the two control groups revealed that wall-to-lumen ratio of arterioles with lumen diameters less than 50 microns tended to be greater in the senescent rats. Capillary numerical density was markedly reduced in the hypertensive animals of both age groups and caused an increase in the mean Krough cylinder radius and in the mean capillary domain. The latter increased by 28-63%; the largest increment occurred in the endomyocardium of the senescent group. A trend toward increased heterogeneity of capillary spacing was also noted in the hypertensive rats. The observed microvascular alterations occurred in the absence of an absolute increase in left ventricular mass but in the presence of cardiocyte hypertrophy. Thus the decrements in capillary numerical density are not only due to inadequate growth but reflect an absolute reduction in the number of these vessels associated with cardiocyte loss. It is concluded that late-onset hypertension in middle-aged and senescent rats is characterized by left ventricular wall remodeling that includes microvascular alterations that would be expected to limit maximal myocardial flow and O2 supply to the cardiocyte.

The Effect of a Reduced Sodium Intake on Post-Renal Transplantation Hypertension in Rats

1984 ◽  
Vol 66 (3) ◽  
pp. 269-276 ◽  
Author(s):  
M. H. De Keijzer ◽  
A. P. Provoost ◽  
E. D. Wolff ◽  
W. J. Kort ◽  
I. M. Weijma ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Systolic Blood Pressure ◽  
Sodium Intake ◽  
Plasma Renin ◽  
Normal Diet ◽  
Transplant Recipients ◽  
Plasma Renin Concentration ◽  
Sodium Diet ◽  
Low Sodium Diet ◽  
Low Sodium

1. In an experimental model of post-renal transplantation hypertension in rats, we studied the effect of a reduction of sodium intake on the development of this type of hypertension. 2. Systolic blood pressure, plasma- renin concentration and renal function were measured regularly in recipients of an allogeneic kidney transplant that had previously undergone active immunological enhancement. 3. Transplant recipients on a normal diet showed a rise in systolic blood pressure during the second week after transplantation. The systolic blood pressure of recipients on a low sodium diet remained normotensive throughout the 15 weeks follow-up period. 4. The plasma renin concentration was low in the hypertensive recipients on a normal diet, as compared with unilaterally nephrectomized controls. Although the plasma renin concentration of recipients on a low sodium diet fell below that of unilaterally nephrectomized controls on a low sodium diet, it was higher than that of recipients on a normal diet. 5. The renal function of transplant recipients was greatly reduced compared with that of control rats. The glomerular filtration rate was reduced to a greater extent than the effective renal plasma flow. 6. In a separate experiment it was revealed that a similar reduction in the glomerular filtration rate of kidneys permanently damaged by temporary ischaemia did not result in an increase in the systolic blood pressure. 7. Survival up to 6 weeks after transplantation was the same for both groups of recipients. Recipients on a low sodium diet, however, showed a better 15 weeks survival, probably owing to the absence of hypertension in this group. 8. The prevention of the development of hypertension by means of a reduction of sodium intake, points to an involvement of sodium retention in this post-transplantation hypertension model.

Influence of bronchomotor tone on airway dimensions and resistance in excised dog lungs

1980 ◽  
Vol 49 (2) ◽  
pp. 270-278 ◽  
Author(s):  
H. L. Hahn ◽  
A. Watson ◽  
A. G. Wilson ◽  
N. B. Pride
Keyword(s):  
Forced Oscillation ◽  
Relative Increase ◽  
Small Airways ◽  
Absolute Increase ◽  
Tissue Resistance ◽  
Before And After ◽  
Large Airways ◽  
The Mean ◽  
Additional Lobes ◽  
Bronchomotor Tone

In 10 excised dog lobes we measured total lobar resistance (Rlo) by forced oscillation at various transpulmonary pressures (Ptp) before and after bronchodilators and obtained simultaneous tantalum bronchograms in 5. Mean airway diameter increased up to a Ptp of 30 cmH2O, although the increase was greater between 0 and 10 cmH2O. In contrast, Rlo decreased between 0 and 10 cmH2O but increased again between 10 and 30 cmH2O. At a Ptp of 30 cmH2O, the mean diameter of small airways (〜 2 mm) increased 31%, that of large airways (〞 7 mm) 2% after aerosolized bronchodilators. At a Ptp of 1 cmH2O, increases were 44 and 15%, respectively. Values of Rlo were reduced at all Ptp after bronchodilator, but minimum Rlo occurred at lower Ptp than before, and the absolute increase in Rlo at greater Ptp was preserved. In four additional lobes, we partitioned Rlo using a retrograde catheter. All of the increase in Rlo at large Ptp was peripheral to the retrograde catheter. We conclude that excised lungs have bronchomotor tone that narrows airways even at high Ptp and that loss of tone magnifies the relative increase in Rlo at high Ptp, supporting suggestions that the increase is due to tissue resistance and hysteresis.

AT1 and TxA2/PGH2 receptors maintain hypertension throughout 2K,1C Goldblatt hypertension in the rat

1996 ◽  
Vol 271 (4) ◽  
pp. R891-R896 ◽  
Author(s):  
C. S. Wilcox ◽  
J. Cardozo ◽  
W. J. Welch
Keyword(s):  
Blood Pressure ◽  
Receptor Antagonist ◽  
Sodium Intake ◽  
Late Phase ◽  
Plasma Renin ◽  
Type I ◽  
Ang Ii ◽  
Control Groups ◽  
The Mean ◽  
Antihypertensive Response

Angiotension II (ANG II) increases the generation of vasoconstrictor prostaglandin endoperoxides (PGH2) and thromboxane A2 (TxA2). Two-kidney, one-clip (2K,1C) Goldblatt hypertensive rats have an increased plasma renin activity (PRA) and ANG II level during the early, but not the late, phases of hypertension. Therefore, the aim of these studies was to compare the antihypertensive efficacy of an ANG II type I (AT1) and a TxA2/PGH2 receptor antagonist during different phases of 2K,1C hypertension. Rats were maintained on a fixed sodium intake for 3 days before and throughout the period of drug administration. These studies assessed the antihypertensive response to administration of the AT1 receptor antagonist losartan (20 mg.kg-1.day-1), the TxA2/PGH2 receptor antagonist ifetroban (20 mg.kg-1.day-1) or vehicle given for 3 days to rats with early (2-4 wk postclip), intermediate (10-12 wk postclip), and late (36-42 wk post-clip) 2K,1C hypertension and to two control groups of rats corresponding in age to the early or intermediate and the late 2K,1C groups. The mean arterial pressure (MAP) was measured directly with indwelling arterial cannulas. The MAP of sham-operated rats was 109 +/- 5 mmHg. In the early phase of 2K,1C hypertension, the MAP was increased to 143 +/- 6 mmHg, and it was increased further to 162 +/- 5 mmHg during the intermediate and to 179 +/- 4 mmHg during the late phase. The PRA, compared with age-matched controls, was increased during early and intermediate, but not late phase 2K,1C hypertension. Neither drug lowered blood pressure in control rats. However, both drugs significantly reduced the blood pressure in the early, intermediate, and late phases of 2K, 1C hypertension. At the end of 3 days of administration, blood pressure in early 2K, 1C rats given losartan was reduced to levels of control rats, but remained slightly elevated in other groups and in those receiving ifetroban. In conclusion, AT1 and TxA2/PGH2 receptors maintain hypertension throughout the evolution of 2K, 1C hypertension in the rat, despite changes in PRA.

Plasma Renin Activity in Normal Human Pregnancy and in Pregnancy-Associated Hypertension, with Reference to Cryoactivation

1980 ◽  
Vol 59 (1) ◽  
pp. 49-53 ◽  
Author(s):  
E. D. M. Gallery ◽  
G. S. Stokes ◽  
A. Z. Györy ◽  
J. Rowe ◽  
J. Williams
Keyword(s):  
Plasma Renin Activity ◽  
Pregnant Women ◽  
Sodium Intake ◽  
Plasma Renin ◽  
Normal Pregnancy ◽  
Renin Activity ◽  
Central Feature ◽  
Plasma Renin Concentration ◽  
Significant Difference ◽  
In Pregnancy

1. Because hypertension is the central feature of pre-eclampsia, and because plasma renin activity is known to be elevated in normal pregnancy (with conflicting results published for pre-eclampsia), a prospective study of plasma renin activity was conducted in pregnancy, under conditions of a fixed sodium intake, in 178 initially normotensive volunteer subjects. Thirty of these women developed pregnancy-associated hypertension (pre-eclampsia) in the third trimester. 2. There was a significant elevation of plasma renin activity from the published values for non-pregnant women, throughout gestation in normotensive women. There was no significant difference, at any stage of gestation, between the values for normal women and those who developed pregnancy-associated hypertension. 3. The extent of cryoactivation of renin, produced by usual collection procedures, was investigated in a subgroup of the total population. It was highly significant and quite variable, but was similar in those who developed pregnancy-associated hypertension and in normal pregnant women. The mean increase in plasma renin concentration in maximally cryoactivated samples was 16-fold. 4. Neither measurement of peripheral plasma renin activity nor of cryoactivatable plasma renin concentration is of value in distinguishing between normal pregnant women and those destined for, or with pregnancy-associated, hypertension.

scholarly journals Immunoglobulin G1 and G2 profile in children with Down syndrome

2017 ◽  
Vol 11 (1) ◽  
pp. 1-4 ◽  
Author(s):  
Supti Prava Saha ◽  
Monsura Khan ◽  
Ashesh Kumar Chowdhury
Keyword(s):  
Down Syndrome ◽  
Age Groups ◽  
Recurrent Infection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Healthy Children ◽  
Normal Children ◽  
Children With Down Syndrome ◽  
Healthy Control ◽  
The Mean ◽  
Two Age Groups

Background and objectives: It is well known that children with Down syndrome (DS) suffer from frequent infections. There is an association of certain IgG subclass abnormalities with the predisposition to recurrent infection of the respiratory tract. Therefore, the study was conducted to determine the immunoglobulin G1 and G2 (IgG1, IgG2) profile in children with DS.Material and methods: Forty children between the ages of 6 months to 12 years with DS (47 XX/XY, +21) attending the Department of Immunology, BIRDEM were enrolled in the study. Age and sex matched 30 healthy normal children with 46 XX/XY were included as control. Enrolled DS and healthy children were divided into two age groups namely 6 months to 6 years and 7 years to 12 years. Serum IgG1 and IgG2 concentrations were determined by enzyme linked immunosorbent assay (ELISA) method.Results: The mean serum IgG1 concentrations of children with DS in both age groups did not differ significantly from that of normal healthy children. But the IgG2 level was significantly less (p<0.003 and p<0.004) in both age groups of children with DS compared to that of control healthy children.Conclusion: The study has demonstrated that the serum IgG2 level was significantly less in children with DS than that of matched normal healthy control children while there was no deficiency of IgG1.IMC J Med Sci 2017; 11(1): 1-4

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