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At least 19 recordsLinked to original sources

PubMed1976

Control of plasma aldosterone in infancy and childhood. A study of plasma renin activity, plasma cortisol and plasma aldosterone.

In order to elucidate the main factors controlling plasma aldosterone in infancy and childhood, plasma renin activity (PRA), plasma cortisol (PC, as a parameter of ACTH activity), plasma aldosterone (PA) and serum sodium and potassium were measured simultaneously in 84 healthy children (62 recumbent, 22 upright) ranging in age from 6 days to 16 years. 10 healthy male students served as adult controls. As compared to the controls, PRA levels were significantly higher in the children up to the age of 12 years. PA was also elevated in most children; the highest values for PA and for PRA were observed during the first 4 years of life. A significant positive correlation between PRA and PA (n = 84, r = 0,62, p less than 0.001) was found. There were no significant differences in serum sodium or potassium or in PC. All PC values were - with one exception - within the range found in healthy adults. Our results indicate that high PA values are freuqently observed in healthy children. They are mainly caused by elevated PRA. The physiological significance of increased activation of the renin-angiotensin-aldosterone system in infancy is not yet clear.

Adolescent↗

PubMed1985

[Effects of a new vasodilator, budralazine on water drinking activity, plasma norepinephrine, plasma angiotensin II, plasma arginine vasopressin, plasma serotonin concentration, urinary aldosterone excretion rate and urinary catecholamine excretion rate in rats].

Present study was undertaken to elucidate the effects of a new vasodilatating antihypertensive drug, budralazine on water drinking behavior and humoral factors including plasma norepinephrine (NE), angiotensin II (A II), arginine vasopressin (AVP), serotonin (5-HT) concentrations, urinary aldosterone and catecholamine excretion rates. After oral budralazine administration (10 mg/kg/day, p.o., for 7 days), systolic tail blood pressure of Wistar Kyoto rats (WKY) decreased significantly. While, heart rate and water drinking activity of WKY significantly increased. Urinary catecholamine excretion rate did not change after oral administration of budralazine (10 mg/kg and 100 mg/kg/day, p.o.; for 7 days). However, significant increase in urinary aldosterone excretion rate was demonstrated. Both plasma A II and NE concentrations tended to increase after oral administration of budralazine (100 mg/kg/day). Plasma AVP and 5-HT concentrations were not influenced by budralazine. These findings suggest that budralazine acts on renin angiotensin aldosterone system as compared to that in the sympathetic nervous system.

Aldosterone↗

PubMed1978

Relationship of basal plasma norepinephrine to blood pressure, plasma renin activity, mineralocorticoids, and plasma volume in essential hypertension.

The basal levels of plasma norepinephrine have been measured in 113 carefully characterized patients with essential hypertension, and the results have been correlated with the PRA sub-grouping and the levels of blood pressure, plasma aldosterone, plasma 18-hydroxy-deoxycorticosterone, and plasma volume. In addition, the influence of furosemide on plasma norepinephrine concentration has been assessed. Essential hypertensives, when considered as a whole, did not exhibit any significant abnormality in basal plasma norepinephrine concentration, but interesting alterations were observed in certain specific sub-groups. High renin patients had significantly elevated levels of basal plasma norepinephrine. In addition, a sub-group of the low renin population who were relatively young had reduced plasma norepinephrine conentration. In these individuals with both reduced PRA and plasma norepinephrine, the levels of both increased concomitantly to the normal range with marked salt depletion. Furosemide administration induced increases in plasma norepinephrine in all PRA sub-groups. Plasma norepinephrine correlated significantly with blood pressure in normal and low renin hypertensives, but the relationships were confined only to male subjects. Significant correlations were also observed between plasma norepinephrine and plasma aldosterine in males with normal PRA but not in the other sub-categories. No significant relationships between plasma volume and either plasma norepinephrine or blood pressure could be detected. Plasma 18-hydroxy-deoxycorticosterone was greater in males as compared with females and appeared elevated above control levels in normal and high renin essential hypertensives. Significant positive correlations between plasma aldosterone and plasma 18-hydroxy-deoxycorticosterone were observed in both males and females with normal renin hypertension. These studies have demonstrated abnormalities in basal plasma norepinephrine concentration in certain patients with essential hypertension. They also suggest that the levels of blood pressure and plasma aldosterone may be related to peripheral sympathetic activity in essential hypertension.

18-Hydroxydesoxycorticosterone↗

PubMed1989

Antihuman plasma glutathione peroxidase antibodies: immunologic investigations to determine plasma glutathione peroxidase protein and selenium content in plasma.

Plasma glutathione peroxidase (GSHPx) (glutathione: H2O2 oxidoreductase) is a unique selenoglycoprotein. Treatment of this enzyme with glycopeptidase F partially deglycosylates it and establishes the presence of N-linked sugar moieties. Antibodies raised in a rabbit against the purified enzyme from plasma were found to be specific, noninhibitory, and capable of precipitating the enzymatic activity. The antibodies precipitated greater than 90% of the GSHPx activity of normal plasma, thus indicating that the selenoenzyme is the main if not the sole GSHPx activity of plasma. The antibodies did not precipitate RBC GSHPx. A slight cross-reactivity of the antibodies was found with rat plasma GSHPx. A GSHPx activity precipitation assay of normal plasma in the presence of selenium (Se)-deficient plasma indicates that no cross-reactive protein in the Se-deficient plasma interferes with the precipitation of the GSHPx activity from normal plasma. Thus, GSHPx protein as well as activity is deficient in plasma in the absence of Se. Antibodies against GSHPx either from RBCs or from plasma were used to specifically immunoprecipitate most of the GSHPx activity from RBCs or plasma, respectively, in healthy individuals to determine the amount of Se associated with the protein. GSHPx accounts for approximately 15% of the Se in RBCs and 12% of the Se in plasma. Thus, in normal individuals, these proteins account for only a fraction of plasma and RBC Se.

Animals↗

PubMed1990

Platelet angiotensin II binding and plasma renin concentration, plasma renin substrate and plasma angiotensin II in human pregnancy.

1. The results are presented of a cross-sectional study of 25 non-pregnant and 125 pregnant/postnatal women in whom platelet angiotensin II binding and plasma angiotensin II, plasma renin concentration and plasma renin substrate were measured. 2. Platelet angiotensin II binding was significantly lower in the first-trimester patients as compared with the non-pregnant women (P less than 0.001). Specific binding remained low in the second and third trimesters, and in those patients studied 24 h after delivery. However, higher values, approximating to the non-pregnant level, were found 6 weeks postnatally (n = 25 for each group). 3. Plasma angiotensin II, plasma renin concentration and plasma renin substrate increased in pregnancy, with the increase becoming statistically significant as compared with the non-pregnant women in the second trimester. Maximal median values of plasma angiotensin II and plasma renin substrate were found in the third trimester, but maximal median values of plasma renin concentration were found in the second trimester. The concentrations of all three hormones fell after delivery. 4. There was an inverse correlation between platelet angiotensin II binding and simultaneously measured endogenous levels of plasma angiotensin II (P less than 0.02) and plasma renin substrate (P less than 0.05) in the 25 non-pregnant subjects. These findings support the concept of the angiotensin II receptor concentration being regulated by the plasma angiotensin II level. There was no correlation between platelet angiotensin II binding and plasma renin concentration.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiotensin II↗

PubMedDate not supplied

Clinical chronopharmacology of ACTH 1-17. II. Effects on plasma testosterone, plasma aldosterone, plasma and urinary electrolytes (K, Na, Ca and Mg).

The aim of the investigation was to study the effects of ACTH 1-17 on plasma testosterone, plasma aldosterone as well as on both plasma and urinary electrolytes (K, Na, Mg and Ca) in healthy young adult males with regard to the time (clock hours) at which this polypeptide was injected. Eight healthy adults (males from 28 to 30 years) volunteered for the study. The were synchronized with a diurnal activity from 0700 to midnight and a nocturnal rest. Each week, during 6 consecutive weeks (January 19 to February 25, 1980) a 3-day test was performed on Saturday, Sunday and Monday. On Sundays 3 control-tests and the 3 ACTH-tests were programmed during which either saline or 100 microgram ACTH 1-17 were injected i.m. at respectively 0700, 1400 and 2100. During each 3 day-test period (72 h) the urinary excretion of K, Na, Mg and Ca was determined every 4 h at fixed clock hours. In addition, on Sundays, venous blood was sampled prior to control or ACTH injections at respectively 0700, 1400 and 2100 and 20, 40, 60, 90, 120, 150 and 180 min thereafter. Plasma testosterone, aldosterone (radioimmunoassays) K, Na (flame photometry), Mg and Ca (photocolorimetric methods) were determined in the collected samples. Both conventional and cosinor methods were used for statistical analyses. The injection of ACTH at 0700 was followed by a clear and statistically significant rise of plasma testosterone. No change with regard to control occurred when ACTH was injected at either 1400 or at 2100. A statistically significant rise of plasma aldosterone was observed after each of the ACTH injections. However, the highest plasma aldosterone level was reached when ACTH was administered at 1400 and the lowest level at 2100. ACTH-induced changes in plasma electrolytes were either nil (for Na and Ca) or small (for K and Mg). A more or less important increase of urinary K occurred after the ACTH injection at each of the 3 considered times. The highest values of excreted K occurred after the injection of ACTH at 0700, without shift of the acrophase. In contrast, injections of ACTH at 1400 and 2100 induced a dramatic alteration of the K rhythms. ACTH induced an important fall in the Na urinary excretion. This fall was the greatest when ACTH was injected at 1400. Na rhythm alterations also occurred, particularly after ACTH injections at 2100. However, this effect was less pronounced after ACTH injection at 0700 than at other considered time points. The urinary amount of excreted Ca did not seem to be affected by ACTH. Rhythm alterations occurred after ACTH injections at 1400 and 2100. Peaks of plasma testosterone, plasma aldosterone as well as plasma cortisol (reported in a previous paper) resulting from ACTH stimulation coincided in time with the acrophase of the physiological circadian rhythm in plasma levels of these hormones...

Adolescent↗

PubMed1992

Formation of an association between factor XII and kallikrein in human plasma--significance of storage of plasma and the functional state of plasma kallikrein.

In a previous study evidence was provided that zymogen FXII might associate with part of the kallikrein generated by acetone treatment of human plasma in the presence of benzamidine (Thromb. Res. 61, 123-133, 1991). Some results also suggested an increase in such a complex formation upon storage of plasma, and two questions were raised in the present study: Does kallikrein activated by acetone-treatment of plasma exist in modifications with different abilities to associate with FXII? And will -70 degrees storage of plasma increase the liability to complex formation? S-2302 amidase assays carried out in mixtures of normal plasma and plasma genetically deficient in prekallikrein (PK) suggested an inhomogeneity of the kallikrein generated. A minor and unstable part of it could be blocked by corn trypsin inhibitor, thus indicating the presence of an association with FXII. In fractions from gel filtration of acetone-activated plasma, kallikrein was assayed as S-2302 amidase, high molecular weight kininogen (HK) was measured in rocket immunoassay, and FXII, PK and HK were studied in PAGE immunoblot experiments. When freshly collected plasma was used, an amidase double peak (mol. wts. 400 and 300 kD) indicated an inhomogeneity of the kallikrein present, HK being observed in both peaks. FXII eluted separately over a gel. mol. wt. range of 90-55 kD. When plasma was stored at -70 degrees for 10 months before use, the more low-molecular part of the kallikrein double-peak had disappeared and was recovered, in a highly unstable state, adsorbed to the column material together with HK and FXII. Accordingly both functional assays and the results of immunoblot experiments indicated an inhomogeneity of the kallikrein present, and also a tendency of the minor part of it to associate with FXII, a tendency increased upon storage of plasma at -70 degrees.

Acetone↗

PubMed1978

Relationship of basal plasma noradrenaline to blood pressure, age, sex, plasma renin activity and plasma volume in essential hypertension.

1. The relationship of basal plasma noradrenaline to blood pressure, age, sex, urinary sodium excretion, and plasma volume has been examined in 117 untreated ambulatory patients with essential hypertension. 2. No significant correlations between basal plasma noradrenaline and either age or sex were apparent in the total group of essential hypertensive patients. In addition, no significant correlations were observed between plasma noradrenaline and 24 h urinary sodium excretion. 3. Basal plasma noradrenaline concentration was significantly higher in high renin essential hypertensive subjects compared with those with normal or low plasma renin activity. 4. Plasma noradrenaline was reduced significantly in relatively young patients with low renin essential hypertension, but appeared to be normal in other low renin subjects. 5. Basal plasma noradrenaline correlated significantly with blood pressure in patients with normal or low renin essential hypertension but the relationships were only significant in male patients. 6. No significant relationship between basal plasma noradrenaline and either blood pressure or plasma volume could be demonstrated in this population of essential hypertensive patients.

Age Factors↗

PubMed1985

Effect of haemodialysis on plasma ADH levels, plasma renin activity and plasma aldosterone levels in patients with end-stage renal disease.

Changes in plasma ADH levels and plasma aldosterone levels (PA) were studied in patients with end-stage renal disease (N = 40). The patients were divided into two groups according to their plasma renin activity (PRA) into a low renin (LR, n = 9) and a high renin group (HR, n = 31). The metabolic clearance rate (MCR) of plasma ADH was also investigated in 4 patients and 5 normal volunteers. Additionally, it was examined whether plasma ADH, aldosterone and renin were permeable through the dialysis membrane. Pre- and post-dialysis plasma ADH levels in LR were similar to those in the HR group. However, pre- and post-dialysis PA in the HR group were significantly greater than those in the LR group. Post-dialysis PRA was significantly increased in HR compared to pre-dialysis, but not in LR. Pre- and post-dialysis plasma osmolality was increased in both groups, but effective plasma osmolality (EPosm) was within the normal range. There was a significant correlation between EPosm and plasma ADH level both before and after haemodialysis, but the majority of the abnormally high values of ADH compared to the normal values was found within the normal range of EPosm. The patients exhibited high blood pressure and a rise in body weight, and haemodialysis caused a significant fall in body weight and blood pressure in both groups. MCR of ADH was significantly lower in the patients than that in normal subjects. Plasma ADH proved to be permeable through the dialysis membrane in all cases, but aldosterone in only a few cases. Renin was not permeable.

Adolescent↗

PubMed1975

Changes in plasma renin substrate, plasma and renal renin, and plasma osmolarity during glycerol-induced acute renal failure in rabbits.

Seven groups of rabbits were studied before or at various intervals after the subcutaneous administration of 50 percent glycerol in isotonic saline (14 ml/kg). A sharp increase in plasma crystalloid osmolarity, due to glycerol reabsorption from the subcutaneous tissue, was detected at 1.5 and 6 hours and was maximal between 12 and 20 hours. Plasma renin activity did not change at 1.5 hours, but it was significantly elevated at 6 hours and maximally increased between 12 and 20 hours. The increase of plasma crystalloid osmolarity might contribute to renin release in this experimental model. Changes in renal renin levels after the administration of glycerol were not significant, although lower renal renin values were consistently found in rabbits with more severe impairment of renal function. Plasma renin substrate increased later than plasma renin activity (20 hours) and remained high after plasma renin activity had returned to normal (48 hours). The increase of plasma renin substrate was interpreted as mainly due to the impairment of renal function, since a positive correlation was found between plasma creatinine and plasma renin substrate.

Acute Kidney Injury↗

PubMedDate not supplied

The relationship of plasma levels of pindolol in hypertensive patients to effects on blood pressure, plasma renin and plasma noradrenaline levels.

1. Fifteen, previously untreated, hypertensive patients were given 20 mg of pindolol, orally. The systolic and diastolic blood pressures fell significantly in 1 h; the effect was maximal 4 h after pindolol, and persisted for at least 8 h. 2. After oral administration of 20 mg of pindolol, its concentration in the plasma reached a peak in 2-3 h. At the end of 8 h, pindolol was not detectable in the plasma. 3. There was a significant relationship between the peak concentration of pindolol in plasma and the maximal change in blood pressure in fifteen previously untreated hypertensive patients. In a separate study of nine-nine hypertensive outpatients taking 15-80 mg of pindolol daily, the blood pressure responses corresponded generally to the concentration of pindolol in plasma 2-3 h after the morning dose. 4. There were no significant changes in plasma renin activity, plasma renin concentration or plasma noradrenaline concentration in the previously untreated patients taking 20 mg of pindolol. There was no relationship between initial plasma renin or noradrenaline levels and blood pressure responses to pindolol. Nor was there any significant relationship between the changes in plasma renin or noradrenaline levels and the changes in blood pressure.

Blood Pressure↗

PubMed1982

Plasma arginine esterase in cystic fibrosis: kinetics of activation, identification as plasma kallikrein, reaction with alpha 2-macroglobulin and comparison with levels in normal plasma.

Treatment of normal plasma with chloroform and ellagic acid yielded esterase activity against tosylarginine methyl ester, which reached a maximum within 2 h. After 2 h most or all of the activity as resistant to inhibition by soybean trypsin inhibitor (STI), but was still sensitive to the low molecular weight inhibitors di-isopropyl fluorophosphate, aprotinin and prolyl-phenylalanyl-arginyl chloromethane. The activity ran in gel chromatography with alpha 2 macroglobulin (ampha 2M), as if it were due to an alpha 2M proteinase complex. The generation of the arginine esterase activity by chloroform and ellagic acid was apparently dependent on the activation of factor XII, being blocked by Polybrene. In plasma pretreated with methylamine-HCl (an inactivator of alpha 2M), the arginine esterase was 95% sensitive to inhibition by STI. With regard to substrate specificity, inhibition characteristics, and gel chromatographic behaviour, it was indistinguishable from plasma kallikrein (EC 3.4.21.34, formerly 3.4.21.8). The chloroform and ellagic acid treatment of plasma resulted in a disappearance of prokallikrein simultaneous with the appearance of the arginine esterase. By these criteria, the arginine esterase activity was attributable entirely to plasma kallikrein either in its free form (methylamine-treated plasma) or bound to alpha 2M (buffer-treated plasma). Comparisons of STI-sensitive and STI-resistant arginine esterase activities of plasma samples from cystic fibrosis patients, obligate heterozyotes or other groups showed no significant differences in levels of activity, kinetics of activation or gel chromatographic behaviour. We conclude that cystic fibrosis is unrelated to any abnormality in plasma arginine esterase activity, contrary to some previous reports.

Carboxylic Ester Hydrolases↗

PubMed1975

The rôle of plasma proteins in chronic expansion of plasma volume in tropical splenomegaly syndrome. III. The interrelationships of albumin, immunoglobulins and plasma volume.

The effect of alterations in serum protein levels on plasma volume in tropical splenomegaly syndrome has been investigated by determining plasma volume, serum albumin, globulin and immunoglobulin levels in 64 adult New Guineans suffering from this disease. Plasma volumes ranged from 51-2 to 129 ml./kg. Significant positive correlations were found between plasma volume and intravascular pools of albumin, IgG and IgM. Multiple regression analysis demonstrated that 70% of the variance in plasma volume in this series was attributable to increases in these three pools, IgM and IgG accounting for 42% of the total and albumin for 28%. It is probable that the unexplained 30% of plasma volume expansion arises through a splenic arterio-venous shunt effect. It is suggested that initially in tropical splenomegaly syndrome the splenic shunt and immunoglobulin overproduction combine to produce expansion of plasma volume and a fall in intravascular colloid osmotic pressure; that the latter provides the stimulus to increased albumin synthesis, and that this further aggravates the plasma volume expansion and the consequent dilutional anaemia commonly seen in this disease.

Blood Proteins↗

PubMed1979

Renin binding proteins in plasma. Binding of renin to some of the plasma protease inhibitors, to lipoproteins, and to a non-trypsin-binding unidentified plasma protein.

Renin is found in mouse plasma as high molecular weight forms, in addition to the fully active 40 000 dalton form. By using freshly 125 I-labelled 40 000 dalton pure submaxillary mouse renin, no binding to plasma proteins was demonstrable. However, unfolding and refolding of the labelled renin by guanidine facilitated binding to specific mouse and human plasma proteins. By using antibodies against individual human plasma proteins, the specific binding proteins were identified to be the plasma protease inhibitors: alpha2-macroglobulin, inter-alpha-trypsin inhibitor, alpha2-antithrombin. Binding was also demonstrated to alpha1- and beta1-lipoproteins, albumin and to a non trypsin binding unidentified plasma protein. No binding to 56 other tested proteins was demonstrable. It is concluded that the native 40 000 renin does not bind, but that a conformational change of the renin molecule most likely is necessary before binding occurs. It is discussed whether or not inactive or high molecular weight forms of renin in plasma are 40 000 renin bound to plasma protease inhibitors and lipoprotein.

Animals↗

PubMed1992

Quantitation of the novel anticonvulsant remacemide in rat and dog plasma and urine: application of the plasma methodology to measure the plasma protein binding of remacemide.

Sensitive and selective methods have been developed for quantitation of the novel anticonvulsant remacemide in rat and dog plasma and urine. The methods employed liquid-liquid extraction (urine) or ion-exchange solid-phase extraction (plasma), with an internal standard, followed by high-performance liquid chromatography with ultraviolet detection. The detection limit for both methods was 10 ng/ml. Overall accuracy was 0.00% for plasma and -1.4% for urine with a precision of 6.04 and 3.87% for plasma and urine, respectively. The standard curves were linear for both plasma and urine over a wide concentration range (9.96-2490 ng/ml). The plasma method was also applied to measurement of in vitro plasma protein binding of remacemide in rat, dog and human plasma.

Acetamides↗

PubMed1975

Plasma catecholamines, plasma renin activity and plasma aldosterone in tetraplegic man, horizontal and tilted.

1. Plasma catecholamines, plasma renin activity, plasma aldosterone and haematocrit were measured in four subjects with physiologically complete cervical spinal cord transections, before, during and after head-up tilt to 45 degrees for 30 min. Plasma catecholamines were measured in five normal male volunteers in the supine position and after head-up tilt to 45 degrees for 10 min. 2. After 10 min of head-up tilt, the plasma noradrenaline rose 14% in the tetraplegic patients and 115% in the control subjects. These findings indicate a failure of sympathetic activity in response to head-up tilt in the tetraplegic patients, probably caused by interruption of pathways by which the brain normally controls sympathetic outflow. 3. In the tetraplegic patients the resting plasma renin activities were above normal, and rose more quickly and greater on head-up tilt than in published studies of normal subjects. It is likely that the renal baroreceptors are important in the control of renin release. 4. In the tetraplegic patients, there was a late rise in plasma aldosterone which was probably due to the elevation in plasma renin activity.

Adult↗

PubMed1984

Effects of plasma infusion on plasma lipids, apoproteins and plasma enzyme activities in familial lecithin: cholesterol acyltransferase deficiency.

The siblings presented here are the third family found in Japan with familial LCAT deficiency. Their post-heparin plasma lipoprotein lipase and hepatic triglyceride lipase activities were measured selectively by an immunochemical method. Plasma triglyceride levels were elevated, and post-heparin plasma lipoprotein lipase was decreased only in a patient with nephropathy, while hepatic triglyceride lipase activities were within reference limits in both patients. The plasma concentrations of apo A-I, apo A-II, and apo B were reduced in both patients. On the other hand, the plasma concentration of apo E was markedly increased. Enzyme replacement therapy by plasma transfusion in the propositus resulted in marked improvement of deranged compositions of triglyceride-rich lipoproteins. Also, improvement of the plasma apo E concentration was demonstrated, while the improvement of post-heparin lipase did not occur. These results suggest that LCAT may play an important physiological role in triglyceride metabolism as well as in cholesterol metabolism.

Apoproteins↗

PubMed1985

Lack of effect of naloxone in a moderate dosage on the exercise-induced increase in blood pressure, heart rate, plasma catecholamines, plasma renin activity and plasma aldosterone in healthy males.

There is evidence that opioid peptides influence blood pressure and heart rate in animals and man. In the present investigation the effect of naloxone on the exercise-induced increase in blood pressure, heart rate, plasma catecholamines, plasma renin activity (PRA) and plasma aldosterone was investigated in nine healthy men. A submaximal work test was performed on two occasions. The test consisted of ergometer bicycling for 10 min on 50% of maximal working capacity immediately followed by 10 min on 80% of maximal working capacity. Ten minutes before exercise the subjects received in a randomized manner a bolus dose of naloxone (10 micrograms/kg) or a corresponding volume of saline followed by a slow infusion (15 ml/h) of naloxone (5 micrograms h-1 kg-1) or saline, respectively. After exercise systolic blood pressure, heart rate, plasma catecholamines, PRA and plasma aldosterone increased during both saline and naloxone infusion. The changes were similar in both studies. Accordingly, opiate receptors sensitive to naloxone in a moderate dosage seem not to be involved in the cardiovascular response and the increase in plasma catecholamines, PRA and plasma aldosterone induced by exercise.

Adult↗