Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0085580 (essential hypertension)
 14,686 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

1. Na+,K(+)-ATPase is the membrane enzyme catalysing the active transport of Na+ and K+ across the plasma membrane of animal cells. A reduced activity of Na+,K(+)-ATPase has been described in gestational hypertension in a variety of cell types, in agreement with the hypothesis that gestational hypertension can induce membrane transport modifications similar to those reported for essential hypertension. The causes of the reduced Na+,K(+)-ATPase activity are still debated. 2. The aim of the present work was to investigate the molecular mechanism of the reduced enzymic activity in gestational hypertension using as a model Na+,K(+)-ATPase purified from human placenta. Na+,K(+)-ATPase obtained from term placentas of eight healthy pregnant women and eight age-matched women with gestational hypertension was purified as previously described. 3. We observed in gestational hypertension: (i) a significant increase in the activation energies above transition temperature; (ii) a significant decrease in the fluorescence polarization of 1-(4-trimethylaminophenyl)-6-phenyl-1,3,5-hexatriene (i.e. increased fluidity) and an increase in the mean lifetime (modified hydrophobicity); (iii) a lower Kq, suggesting an enzymic structural modification; and (iv) an increased mean lifetime and rotational relaxation time of pyrene isothiocyanate, indicating a modified ATP binding site.
 ...
PMID:Na+,K(+)-ATPase of human placenta during gestational hypertension: a biochemical-biophysical study. 897 7

1. Increased affinity for sodium (Km) at an external site of the sodium-lithium countertransporter and altered membrane microviscosity in the surface regions of the lipid bilayer identifies a group of essential hypertensive patients with a genetic predisposition to hypertension. The present study investigated the kinetic properties of the sodium-lithium countertransporter and membrane microviscosity in patients with hypertension, renal disease and impaired renal function. 2. Sixty patients with renal disease (28 chronic renal failure, 30 hypertensive, 23 family history of hypertension) were investigated. Standard erythrocyte sodium-lithium countertransport activity, sodium affinity constant (Km), maximum reaction velocity (Vmax) and membrane microviscosity were measured. 3. Patients with renal disease and a family history of hypertension had significantly lower Km (P < 0.05) values and raised membrane microviscosity measured by 1-(4-trimethylammoniumphenyl)-6-phenyl-1,3,5-hexatriene anisotropy (P < 0.05) compared with patients without a family history of hypertension. 4. Uraemic subjects had low K(m) values compared with patients with renal disease and normal renal function (P < 0.05). However, there was no significant difference in membrane microviscosity between uraemic and non-uraemic subjects. 5. In patients with a family history of hypertension, sodium-lithium countertransport activity and 1-(4-trimethylammoniumphenyl)-6-phenyl-1,3,5-hexatriene anisotropy are important markers of cellular changes in essential hypertension, independent of renal disease. Uraemia, independently of hypertension, produces an alteration in the function of the sodium-lithium countertransporter which has previously been associated with a genetic predisposition to hypertension and cardiovascular disease.
 ...
PMID:Raised affinity for extracellular sodium of the sodium-lithium countertransporter is associated with a family history of hypertension and uraemia in patients with renal disease. 917 24

In subjects with essential hypertension we evaluated, respectively, the red cell membrane protein lateral mobility (obtained marking intact red blood cells with pyrene-3-maleimide (3-PM)), the erythrocyte membrane fluidity (obtained marking intact erythrocytes with 10-(1-pyrene) decanoic acid), the red cell membrane transverse fluidity gradient (obtained marking intact red blood cells with a set of fatty acid fluorescent probes (2-AP, 6-AS, 9-AS, 12-AS)), the platelet membrane fluidity (obtained marking intact and unstimulated platelets with 1,6-diphenyl-1,3,5-hexatriene (DPH) and with 1-(4-(trimethylamino)phenyl)-6-phenyl-1,3,5-hexatriene (TMA-DPH)) and the polymorphonuclear membrane fluidity (obtained marking intact and unstimulated polymorphonuclear cells with TMA-DPH). From the obtained data it is evident that: (1) red cell membrane protein lateral mobility does not distinguish normals from hypertensives; (2) erythrocyte membrane fluidity and red cell membrane transverse fluidity gradient clearly discriminate normals from hypertensives; (3) platelet membrane fluidity differentiates normals from hypertensives only when DPH is used as fluorescent probe; (4) polymorphonuclear membrane fluidity does not distinguish normals from hypertensives. Our results show that in essential hypertension a different behaviour of the membrane dynamic properties in the circulating blood cells is evident.
 ...
PMID:Erythrocyte, platelet and polymorphonuclear leukocyte membrane dynamic properties in essential hypertension. 935 84

The aim of the study was to evaluate the polymorphonuclear leukocyte (PMN) membrane fluidity and PMN cytosolic Ca2+ content in several clinical conditions: diabetes mellitus, vascular atherosclerotic disease (VAD), chronic renal failure (CRF), essential hypertension (EH). In 13 subjects with insulin-dependent diabetes mellitus (IDDM), in 24 subjects with non-insulin-dependent diabetes mellitus (NIDDM), in 42 VAD subjects, in 23 VAD subjects with NIDDM, in 15 subjects with CRF and in 12 subjects with EH, we determined the PMN membrane fluidity, obtained marking unstimulated PMN cells with fluorescent probe 1-[4-(trimethylamino)phenyl]-6-phenyl-1,3,5-hexatriene (TMA-DPH), and considering the fluorescence polarization degree, and the PMN cytosolic Ca2+ content, obtained marking unstimulated PMN cells with the fluorescent probe Fura2-AM and considering the ratio between the Fura2-Ca2+ complex and the unchelated Fura 2 fluorescence intensity. From the obtained data it is evident that PMN membrane fluidity does not distinguish normals from IDDM subjects, NIDDM subjects, VAD subjects with and without NIDDM, CRF subjects and hypertensives. PMN cytosolic Ca2+ content, in comparison with normal controls, is significantly increased in VAD subjects (p < 0.01), in VAD subjects with NIDDM (p < 0.001), in CRF subjects (p < 0.001) and in hypertensives (p < 0.05). No correlation was found between PMN membrane fluidity and PMN cytosolic Ca2+ content. The study of these PMN parameters can be useful in the understanding of the role of leukocytes in the vascular damage that characterizes these clinical conditions.
 ...
PMID:Polymorphonuclear leukocyte membrane fluidity and cytosolic Ca2+ content in different clinical conditions. 935 86