Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P50583 (asymmetrical)
 12,197 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A frequency distribution curve and interval percentages of variations in right versus left renal vein renin (RVR) were calculated from 227 sets of renin data from patients with mild and moderate essential hypertension (EH). A renal vein renin ratio (RVRR), large/small, of approximately 2.0 or more falls beyond the 95 per cent confidence interval, and may therefore by considered to be abnormal. Although assay variability and sampling errors may contribute to artifactually large RVRR's in EH, they usually indicate true disparity, probably secondary to asymmetrical nephrosclerosis. Recent hypotheses regarding diagnostic value of RVR in hypertension are evaluated in light of data yielded by this investigation. Simultaneous and/or replicate sampling should reduced within-patient variability and improve clinical interpretation of test results.
 ...
PMID:Renal vein renin in essential hypertension. 119 55

Variations in flow rate through the loop of Henle in the range of 0--50 nl/min were induced using pressure controlled microperfusion. Simultaneously, with the aid of a second pressure-microperfusionsystem, the glomerular function of the same nephron was studied by continuous measurement of two parameters, early proximal flow rate (EPFR) and/or stop flow pressure (SFP). Elevation of loop perfusion above physiological values (40 nl/min) resulted in a drop of EPFR and SFP, whereas lowering perfusion rates had no effect. This feedback behaviour was studied in kidneys with different renin contents to test the role of the renin-angiotensin system in the mediation of the macula densa signal to the adjacent glomerular vessels. Renal renin content, measured after micropuncture experiments by incubation with substrate followed by radioimmunoassay of angiotensin I, was unaltered in control (Ia) and heminephrectomized rats (Ib), lowered in contralateral kidneys of 2 kidneys Goldblatt hypertensive rats (IIa), in DOCA- and salt-loaded rats (IIb), and in DOCA-, salt-loaded and heminephrectomized rats (IIc), and it was evaluated in clipped kidneys of Goldblatt hypertension rats (IIIa). Micropuncture evaluation of the tubuloglomerular feedback behaviour in these experimental groups revealed the following results: 1. a feedback response under all conditions independent of the widely varying renin contents (1000-fold), 2. an asymmetrical behaviour of the feedback response in all kidneys as demonstrated by suppression of EPFR and SFP at elevated loop flow rates, but no change of these parameters when loop flow was interrupted. 3. compared to controls the decrease of each GFR parameter between 0 and 40 nl/min loop perfusion was lower in DOCA- and salt-loaded rats (IIb, IIc). Additional heminephrectomy (IIc) had no further influence on the reduced feedback response in DOCA- and salt-loaded rats, whereas this maneuver reduced the renal renin content drastically. A somewhat higher response than in controls was found in heminephrectomized rats (IIb) and in clipped kidneys of Goldblatt hypertensive rats (IIIa). These different magnitudes of feedback responses do not correlate with the renal renin content. It has been concluded, therefore, that renal renin activity is not the sole determinant of the effectiveness of the tubuloglomerular feedback response.
 ...
PMID:Tubuloglomerular feedback in rat kidneys of different renin contents. 123 32

The data on plasma renin activity (PRA) obtained by catheterization of renal veins in 272 patients with essential arterial hypertension (EH) are reported. In order to exclude a secondary nature of hypertension, all patients were hospitalized and submitted to the extensive clinical and laboratory examinations (according to the protocol) including renal angiography. The aim of the work was to get evidence whether in the apparently homogeneous group of patients with EH there are differences in renin activity between the renal veins giving the quotient (Q) higher than 1.5, and possibly to recognize the clinical meaning of the differences of Q found. In the examined patients as a whole regardless of PRA, 50 of them (18.3%) showed Q greater than or equal to 1.5 and among them in 16 (5.8%) patients Q greater than or equal to 2 was found. The patients were divided according to PRA into those with low, normal and high PRA. In the hyperreninemic group of patients no Q greater than or equal to 2.0 has been found. In the hyporeninemic group 9 patients (9.9%) exhibited Q greater than or equal to 2.0. Although, one does not expect in EH to find differences in PRA between left and right renal vein, we have found the values of Q greater than or equal to 1.5 in nearly 1/5 of our patients. These differences found could be resulting from the existence of asymmetrical angiosclerotic or other renal pathological changes that can not be examined by the available clinical methods.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:[Renin levels in renal veins in patients with essential arterial hypertension]. 268 9

A multimodality radioimmunological and clinicobiochemical study showed an increase in the hydrocortisone level and a decrease in the ACTH level in breast cancer patients. Stage I, following radical mastectomy (RM). A simultaneous increase in the hydrocortisone, ACTH and aldosterone level after RM, chemotherapy, hormone therapy was noted in all patients with breast cancer, Stages II and III, with initially lowered hydrocortisone and aldosterone levels and an elevated ACTH level. After RM and radiotherapy the level of hydrocortisone decreased, that of ACTH and aldosterone and renin activity increased. Scintigraphically in Stage I breast cancer the adrenals were enlarged, after RM in some cases they remained enlarged, in other cases they returned to normal. Enlarged adrenals with a lowered contrast and enhanced obscurity of the contours were observed in Stage II and III breast cancer. After therapy the adrenals remained asymmetrical with a low contrast.
 ...
PMID:[Combined examination of the hypophysis-adrenal cortex system in breast cancer]. 402 50

Between April 1978 and April 1981, 70 patients with hypertension and renal artery stenosis were treated by percutaneous transluminal arterial dilatation. Selection of the patients was based solely on arteriographic criteria. Arteriography after dilatation showed considerable widening of the stenosed area in all patients. In 65 patients the effect of treatment on the blood pressure was assessed during follow up periods of one to four years. In 14 of these patients the hypertension was cured, in 29 it was improved, and in 22 there was no change. Patients with fibromuscular lesions benefited distinctly more than did those with atheromatous stenosis, only one of the 21 patients with fibromuscular lesions showing no change as compared with 21 of the 44 patients with atheromatous lesions. The only serious complication encountered was microcholesterol emboli, which developed in two patients with severe atheromatous lesions of the aorta. In the atheromatous group age and overall renal function had no influence on the blood pressure response. In the subgroup of patients with a unilateral lesion the renal vein renin ratios and asymmetrical curves obtained by renography had only a very limited predictive value. In experienced hands percutaneous transluminal arterial dilatation is relatively safe, and this study suggests that it should be attempted in all patients with renal artery stenosis. Only in patients with severe atheromatosis of the aorta should the risk associated with the catheterisation be weighed against the 50% or so chance of benefit from the procedure.
 ...
PMID:Follow up study of 70 patients with renal artery stenosis treated by percutaneous transluminal dilatation. 622 85

Two women with spontaneous hypokalemia (1 normotensive, 1 hypertensive in the absence of renal artery stenosis), underwent unilateral nephrectomy because of angiographic and/or split renin-based suspicion of a reninoma. The normotensive patient clinically resembled Bartter syndrome but had some elements suggestive of a renin-secreting tumour, justifying surgical exploration and resection. The hypertensive patient presented clinically as a typical reninoma except for negative angiography. Surprisingly, the histology of the kidneys in both cases demonstrated juxtaglomerular hyperplasia without evidence of reninoma. The postoperative follow-up (8 and 19 yrs, respectively) has shown in the normotensive patient a considerable improvement in the hyper-reninism and previously uncontrollable hypokalaemia and in the hypertensive patient a complete normalisation of BP, renin and electrolyte status. Although the histological condition of the contralateral kidneys remains unknown in both patients the preoperative lateralisation of hyper-reninism to one kidney, the postoperative complete relief of the hyper-reninism in the hypertensive patient after uninephrectomy and its decrease, exceeding that corresponding to the removal of one kidney in the normotensive patient, suggest that the juxtaglomerular hyperplasia might have been unilateral or asymmetrical and that nephrectomy may, unexpectedly, relieve the hyper-reninism caused by juxtaglomerular hyperplasia. An increased unilateral susceptibility to trophic or renin-releasing factors or an asymmetrical abnormality in the macula densa-initiated mechanism of juxtaglomerular hyperplasia may be implicated in this disorder.
 ...
PMID:Unilateral juxtaglomerular hyperplasia, hyperreninism and hypokalaemia relieved by nephrectomy. 845 May 25

The physicochemical properties of water enable it to act as a solvent for electrolytes, and to influence the molecular configuration and hence the function--enzymatic in particular--of polypeptide chains in biological systems. The association of water with electrolytes determines the osmotic regulation of cell volume and allows the establishment of the transmembrane ion concentration gradients that underlie nerve excitation and impulse conduction. Fluid in the central nervous system is distributed in the intracellular and extracellular spaces (ICS, ECS) of the brain parenchyma, the cerebrospinal fluid, and the vascular compartment--the brain capillaries and small arteries and veins. Regulated exchange of fluid between these various compartments occurs at the blood-brain barrier (BBB), and at the ventricular ependyma and choroid plexus, and, on the brain surface, at the pia mater. The normal BBB is relatively permeable to water, but considerably less so to ions, including the principal electrolytes Brain fluid regulation takes place within the context of systemic fluid volume control, which depends on the mutual interaction of osmo-, volume-, and pressure-receptors in the hypothalamus, heart and kidney, hormones such as vasopressin, renin-angiotensin, aldosterone, atriopeptins, and digitalis-like immunoreactive substance, and their respective sites of action. Evidence for specific transport capabilities of the cerebral capillary endothelium, for example high Na+K(+)-ATPase activity and the presence at the abluminal surface of a Na(+)--H+ antiporter, suggests that cerebral microvessels play a more active part in brain volume regulation and ion homoeostasis than do capillaries in other vascular beds. The normal brain ECS amounts to 12-19% of brain volume, and is markedly reduced in anoxia, ischaemia, metabolic poisoning, spreading depression, and conventional procedures for histological fixation. The asymmetrical distributions of Na+ K+ and Ca2+ between ICS and ECS underlie the roles of these cations in nerve excitation and conduction, and in signal transduction. The relatively large volume of the CSF, and extensive diffusional exchange of many substances between brain ECS and CSF, augment the ion-homeostasing capacity of the ECS. The choroid plexus, in addition to secreting CSF principally by biochemical mechanisms (there is an additional small component from the extracellular fluid), actively transports some substances from the blood (e.g. nucleotides and ascorbic acid), and actively removes others from the CSF. In contrast with CSF secretion, CSF reabsorption is principally a biomechanical process, passively dependent on the CSF-dural sinus pressure gradient. Pathological increases in intracranial water content imply development of an intracranial mass lesion. The additional water may be distributed diffusely within the brain parenchyma as brain oedema, as a cyst, or as increase in ventricular volume due to hydrocephalus. Brain oedema is classified on the basis of pathophysiology into four categories, vasogenic, cytotoxic, osmotic and hydrostatic. The clinical conditions in which brain oedema presents the greatest problems are tumour, ischaemia, and head injury. Peritumoural oedema is predominantly vasogenic and related to BBB dysfunction. Ischaemic oedema is initially cytotoxic, with a shift of Na+ and CI- ions from ECS to ICS, followed by osmotically obliged water, this shift can be detected by diffusion-weighted MRI. Later in the evolution of an ischaemic lesion the oedema becomes vasogenic, with disruption of the BBB. Recent imaging studies in patients with head injury suggest that the development of traumatic brain oedema may follow a biphasic time course similar to that of ischaemic oedema. Hydrocephalus is associated in the great majority of cases with an obstruction to the circulation or drainage of CSF, or, occasionally, with overproduction of CSF by a choroid plexus papilloma. In either case, the consequence is a ris
 ...
PMID:The normal and pathological physiology of brain water. 907 71

A conformational analysis of a stereochemically complete set of peptide analogues based on a cis-enediol unit is presented. The cis-enediol unit, which can replace a two or a three amino acid segment of a peptide, contains two "side chains", four asymmetrical carbon atoms, and six free dihedral angles. To determine the accessible conformational space, the molecules are divided into three fragments, each containing two free dihedral angles. The energy surfaces are computed for all dihedral angle values, and the possible conformations of the cis-enediol unit analogues are built using all combinations of the surface minima. Such a "build-up" procedure, which is very fast, is able to reproduce 75% of the minima obtained from a full dihedral angle exploration of the conformational space. The cis-enediol unit minima are compared with the corresponding di- and tripeptide minima; all peptide minima can be closely matched by a cis-enediol unit minimum of low energy (less than 2.2 kcal/mol above the lowest energy conformer). However, there are low energy minima of the cis-enediol unit that have no corresponding minima in peptides. The results are shown to depend strongly on the chirality of the analogues. The ability of each of the stereoisomers to mimic natural peptides, evaluated by the present approach, is correlated with its experimental activity in a renin inhibition assay.
 ...
PMID:Conformational analysis of a stereochemically complete set of cis-enediol peptide analogues. 1222 61

There are important asymmetries in brain functions such as emotional processing and stress response in humans and animals. Knowledge of the bilateral distribution of brain neurotransmitters is important to appropriately understand its functions. Some peptides such as those included in the renin-angiotensin system (RAS) and cholecystokinin (CCK) are related to modulation of behavior and stress. However, although angiotensin AT1 and CCK type 2 receptors were found in adult rat brain, there are no studies of their bilateral distribution in stress-related areas. The function of angiotensin peptides is depending on the action of several aminopeptidases (AP) called angiotensinases, some of them being also involved in the metabolism of CCK. We have studied the bilateral distribution of soluble (SOL) and membrane-bound (MEM) alanyl- (AlaAP), cystinyl- (CysAP), glutamyl- (GluAP) and aspartyl- (AspAP) AP activities in stress-related areas such as amygdala, hippocampus and medial prefrontal cortex of adult male rats in resting conditions. These enzymes are involved in the metabolism of angiotensins (AlaAP, CysAP, GluAP, AspAP) and CCK (GluAP, AspAP). In the amygdala, all the activities studied showed a right predominance with a significant difference ranging from 30% for SOL CysAP to 125% for SOL GluAP. In the hippocampus, there was a left predominance for SOL AlaAP, SOL and MEM CysAP and MEM AspAP activities (100, 80, 300 and 100% higher, respectively). In contrast, GluAP predominated remarkably in the right hippocampus (eight-fold for SOL and three-fold for MEM). In the prefrontal cortex, SOL and MEM CysAP and SOL AspAP predominated in the left hemisphere (40, 100 and 40% higher, respectively). These results demonstrated a heterogeneous bilateral pattern of angiotensinase activities in motivation and stress-related areas. This may reflect an uneven asymmetrical distribution of their endogenous substrates depending on the brain location and consequently, it would be also a reflect of the asymmetries in the functions they are involved in.
 ...
PMID:Angiotensinase activity is asymmetrically distributed in the amygdala, hippocampus and prefrontal cortex of the rat. 1558 18

1. The aim of the present study was to examine the acute effects of cortisol infusion on plasma nitrate/nitrite (NO) activity and forearm vascular responsiveness to acetylcholine. 2. We performed two randomized, placebo-controlled, cross-over studies. Study A examined the effects of intravenous hydrocortisone (200 mg over a 3 h period) on blood pressure (BP) and plasma NO activity in six healthy male volunteers. Study B examined the effects of intra-arterial hydrocortisone on cholinergic vasodilator responsiveness in six healthy male volunteers. Vasodilator responsiveness was measured by bilateral strain gauge plethysmography. 3. In study A, there was no significant change in BP during the hydrocortisone infusion. Comparing values obtained following 180 min infusion of hydrocortisone and control, there were significant increases in plasma cortisol (3441 +/- 342 vs 209 +/- 29 nmol/L, respectively; P < 0.001) and glucose (5.7 +/- 0.2 vs 4.6 +/- 0.2 mmol/L, respectively; P < 0.05) and a reduction in plasma renin concentration (PRC) (8.1 +/- 1.2 vs 11.0 +/- 1.8 pg/mL, respectively; P < 0.05) following hydrocortisone infusion. However, there were no significant changes in either plasma NO or in the endogenous NO synthase inhibitors asymmetrical and symmetrical dimethylarginine. 4. In study B, there was no significant change in BP or in cholinergic vasodilator responsiveness during the hydrocortisone infusion. 5. Short-term cortisol infusions do not alter biochemical or physiological markers of NO activity. If cortisol-induced hypertension is mediated by suppression of NO activity in humans, it seems likely that these changes take more than 3 h to become detectable.
 ...
PMID:Acute effects of hydrocortisone on plasma nitrate/nitrite activity and forearm vasodilator responsiveness in normal human subjects. 1574 97


1 2 Next >>