Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0020538 (hypertension)
 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Basal adenylate cyclase activity was similar in plasma membranes prepared from the lungs of 12 week old spontaneously hypertensive rats (SHR) and normotensive Wistar Kyoto rats (WKY). However, sensitivity to Gpp[NH]p, isoproterenol plus GTP or Gpp[NH]p was significantly greater in the SHR. Beta-receptor density measured by [3H]DHA binding was unaltered. The dissociation constant, Kd, revealed a significantly greater binding affinity of the radioligand in the SHR (6.23 +/- 0.45 nM) compared with the WKY (8.53 +/- 0.82 nM). Activity of Gs was assessed by complementing S49 cyc- acceptor membranes with lung cholate extract. Basal activity of the reconstituted system was decreased 43% in the SHR. However, sensitivity to NaF, Gpp[NH]p, and isoproterenol plus Gpp[NH]p was significantly elevated. These data suggest that desensitization of the adenylate cyclase complex is not a generalized response to chronic hypertension. A tissue specific increase in sympathetic drive appears to be responsible for the lowered concentration of cardiac beta-adrenoceptors in the SHR. In contrast, both indirect and direct evidence indicate an enhanced functional sensitivity of pulmonary Gs in the hypertensive rats.
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PMID:Supersensitivity of beta-adrenoceptor coupled adenylate cyclase in pulmonary tissue of the spontaneously hypertensive rat. 255 17

Properties of cardiac beta-adrenergic receptors from two kidney-one clip hypertension and control rats were studied to determine whether or not alterations in the receptor contribute to the decreased responsiveness of two kidney-one clip rat hearts to adrenergic stimulation. The number and affinity of the beta-receptors were assessed by the binding of [3H]DHA in an enriched ventricular membrane fraction obtained from the rat hearts 3 and 4 weeks after the application of the clip. In the rats with 3 weeks of development of hypertension no significant difference was found neither in the number nor in the affinity of receptors (30.9 +/- 5.3 fmol/mg protein, KD: 1.62 +/- 0.43 nM) compared to the control rats (33.3 +/- 6.3 fmol/mg protein, KD: 2.21 +/- 0.59 nM). In rats with 4 weeks of development of hypertension, there was an increased number of receptors (54.7 +/- 3.7 fmol/mg protein, KD: 1.41 +/- 0.17 nM) compared with control rats studied in paralleled conditions (40.0 +/- 2.3 fmol/mg protein, KD: 1.13 +/- 0.12 nM). These results suggest that the reported beta-adrenergic subsensitivity in this model of hypertensive rats could be mediated by a biochemical mechanism other than a direct alteration of the beta adrenergic receptors, and that there is a compensatory increase in the density of receptors during the development of the hypertension.
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PMID:[Myocardial beta adrenergic receptors in experimental renal hypertension, type Goldblatt II]. 286 67

The author found that the onset of hypertension or hypotension is relatively often associated with infections or development of so-called "sneezing due to allergy to pollen or dust," with or without headache, or due to trauma to the occipital area of the head. Using the "Bi-Digital O-ring Test," it was possible to demonstrate that, among bacterial and viral infections, the most common cause of infection associated with the appearance of hypertension is chlamydia, herpes simplex virus, cytomegalovirus, or Epstein-Barr virus. Particularly chlamydia and/or herpes simplex virus, with or without coexistence of other microbes, is usually present at the heart representation area of the medulla oblongata, especially at the left ventricular representation area, often accompanied by upper respiratory infection, cephalic, cervical or facial pain, with or without coexisting genito-urinary infection. The left ventricular representation area of the medulla oblongata is usually located at the right side. In most hypertensive patients, the left ventricular representation area of the medulla oblongata is enlarged up to 3 or 4 times normal size. Sufficient antibiotic treatment of chlamydia with erythromycin sometimes eliminated severe hypertension which appeared after chlamydia infection. In the presence of viral infections, such as herpes simplex, which is also causing severe pain in the head or neck, oral administration of acyclovir, erythromycin, or EPA (Eicosa Pentaenoic acid)-DHA (docosa hexaenoic acid) Omega 3 fish oil often reduced associated intractable pain and hypertension toward the normal level. Thus, the author is proposing new possible mechanisms as among the causes of so-called essential hypertension as a result of microbial infection or trauma of the cardiovascular representation area, particularly that of the left ventricular representation area at the right side of the medulla oblongata.
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PMID:Microbial infection or trauma at cardiovascular representation area of medulla oblongata as some of the possible causes of hypertension or hypotension. 290 10

The effect of cardiac hypertrophy on beta-adrenergic receptor density and affinity was studied under 4 experimental conditions: in the spontaneously hypertensive rat (SHR), in the 2K-1C renal hypertensive rat (RHR), and following subcutaneous infusions of 2 pressor agents; epinephrine (E) and angiotensin II(AII). Using the antagonist 3H-dihydroalprenolol [( 3H]-DHA), the number of binding sites was shown to significantly decrease at both 13 and 24 weeks of age in the SHR when compared to age-matched WKY, with no change in affinity. In the RHR a significant increase in binding sites was observed at both 6 and 10 weeks after clipping, returning towards normal levels following removal of the clipped kidney. Cardiac hypertrophy and hypertension were induced by subcutaneous infusions for up to 2 weeks of both E and AII. E caused an alteration in receptor density, causing a significant decrease with no change in affinity. In contradistinction, although the degree of hypertrophy was the same following AII, no changes in receptor density or affinity were seen. These present experiments confirm our hypothesis that different models of hypertensive hypertrophy are associated with varying changes in beta-adrenergic receptors. This suggests that any consequential changes in myocardial function may be a result of other post receptor mechanisms.
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PMID:Beta-adrenergic receptors in rat myocardium during the development and reversal of hypertrophy and following chronic infusions of angiotensin II and epinephrine. 299 Mar 66

To study potential central adrenoceptor alterations in the hypertension, we have determined alpha 1, alpha 2 and beta-adrenoceptors using [3H]WB4101, [3H]yohimbine and [3H]DHA in the brain regions of spontaneously hypertensive rats (SHR), stroke-prone SHR (SHRSP) and renal hypertensive rats. There was a significant increase in specific [3H]WB4101 binding only in the hypothalamus of SHR and SHRSP at 16-24 weeks of age compared to that of age-matched Wistar-Kyoto rats (WKY). Scatchard analysis revealed a 28-33% increase in the Bmax value for hypothalamic [3H]WB4101 binding without a change in the Kd value, suggesting a change in the receptor density. An increased density of alpha 1-adrenoceptors was consistently observed in the prehypertensive (5 weeks) and developmental (10 weeks) stages of spontaneous hypertension. In contrast, there was no alpha 1-adrenoceptor alteration in the hypothalamus of rats with renal hypertension. The receptor alteration in the SHRSP hypothalamus was not abolished by a chronic hypotensive treatment which prevented the development of hypertension, thereby suggesting that an increased density of the alpha 1-adrenoceptors in spontaneous hypertension does not occur secondarily to the elevation of blood pressure. The SHRSP hypothalamus showed significantly lowered levels of noradrenaline. There was no change in specific binding of [3H]yohimbine and [3H]DHA in the brain regions of SHRSP, except the brainstem which showed a significant decrease in the [3H]yohimbine binding. Thus, the present study suggests an important role for hypothalamic alpha 1-adrenoceptors in the pathogenesis of spontaneous hypertension.
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PMID:Specific increase of hypothalamic alpha 1-adrenoceptors in spontaneously hypertensive rats: effect of hypotensive drug treatment. 299 33

14 male patients with moderate essential hypertension were treated in the cross-comparison with a mackerel and herring diet, respectively, for two weeks. The mackerel diet contained double as much eicosapentaenic (EPA) and docosahexaenic acid (DHA) as the herring diet which served as control. In the serum triglycerides particularly DHS, in the cholesterol esters above all EPA were enriched. In the phospholipids the increase of the two fatty acids was approximately the same. At the end of the mackerel period the serum triglycerides, the total and LDL-cholesterol, the activity of the lecithin-cholesterol-acyl-transferase (CALT) and the serum sodium were significantly decreased. On the other hand, the HDL-cholesterol and the uric acid in the serum significantly increased. Under influence of the herring diet the parameters mentioned appeared only slightly changed. After the mackerel diet also a significantly lower systolic blood pressure was found. The systolic and diastolic blood pressure during a standardized psychophysiological stress test was more diminished at the end of the mackerel period than after the herring diet. The plasma renin activity (PRA) was increased after the mackerel diet. Its increase under the stress test could no more be proved at the end of the mackerel diet. In similar way the stress-conditioned increase of thromboxane B2 could no more be observe both after mackerel and after herring diet. When the results should confirm themselves in long-term studies, a mackerel diet in practicable dosage can be recommended as non-medicamentous treatment of moderate hypertension.
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PMID:[Changes in blood pressure and serum lipids with fish diets in patients with mild essential hypertension]. 300 68

Twelve male patients with mild essential hypertension were put on a diet supplemented with 2 cans of mackerel/day (= 2.2 g daily of eicosapentaenoic acid, EPA, C20:5 n-3 and 2.8 g daily of docosahexaenoic acid, DHA, C22:6 n-3) for 2 weeks within an isocaloric regimen and then with 3 cans/week (= 3.3 g/week, equivalent to 0.47 g daily of EPA and 4.2 g/week, equivalent to 0.69 g daily of DHA) for 8 months with a subsequent period of 2 months on normal diet. Eleven male hypertensives matched for age, body weight index, blood pressure and serum lipids with no change in their nutritional habits served as controls. After the first dietary period (2 weeks) a significant decrease of serum triglycerides (TG), total and LDL-cholesterol, blood pressure and thromboxane B2 (TxB2) was found, whereas HDL cholesterol and potassium in erythrocytes were significantly increased. During the second dietary period (8 months) providing the lower dose of EPA, serum lipids and the other biochemical parameters returned to the initial values. Blood pressure, however, remained significantly lower and rose to the basal levels only after the third period (2 months) on normal diet. In the control group no alterations could be seen. The data suggest a dose-related differential effect of dietary EPA on serum lipids, lipoproteins, TxB2 and blood pressure in subjects with mild hypertension.
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PMID:Long-term effect of mackerel diet on blood pressure, serum lipids and thromboxane formation in patients with mild essential hypertension. 302 12

The binding of 3H-dihydroalprenolol, a beta-antagonist, with the fat cell plasma membrane was studied in spontaneously hypertensive rats and in patients with essential hypertension. It was found that, as compared to control rats, hypertensive animals had an increased maximum number of 3H-DHA binding sites in the membranes and diminished affinity of beta-adrenoreceptors. It is suggested that these differences may play an essential role in the latered sensitivity to adrenalin in hypertensive rats. Removal of the adrenal, i. e. deprivation of the stabilizing corticosteroid effect, leads to marked changes in the state of the beta-adrenoreceptors in hypertensive animals. Thus, the maximum number of binding sites reduces in hypertensive rats but remains unaltered in the controls; following adrenalectomy the affinity of beta-adrenoreceptors increases in rats with hypertension, but in normal rats, on the contrary, does not change or rather has a tendency to decrease.
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PMID:[Characteristics of 3H-dihydroalprenolol binding to beta-receptors in the fat cells of rats and spontaneous genetic hypertension and in hypertensive disease]. 624 54

The possible contribution of changes in cardiac beta-adrenoceptors to alterations in cardiac responses to isoprenaline were investigated in hearts isolated from rats with renovascular hypertension (two-kidney, one-clip Goldblatt), 6, 12 and 18 weeks after renal artery clipping. Cardiac responses were determined in vitro (Langendorff preparation), and ventricular beta-adrenoceptors [( 3H]dihydroalprenolol, [3H]DHA) were then assayed in the same 44 hearts. There was no difference between renovascular hypertensive rats (RHR) and matched normotensive controls as regards chronotropic responses to isoprenaline or in atrial beta-adrenoceptor numbers or apparent affinity. Inotropic responses were significantly lower in all stages of RHR than in matched normotensive controls. There was also a significant (P less than 0.001) decrease in ventricular beta-adrenoceptor density with no significant change in apparent affinity (Kd). Inotropic responsiveness to isoprenaline (max. increment in peak dP/dt) was significantly correlated with ventricular beta-adrenoceptor density (r = 0.54, P = 0.0005). These results suggest that the reduction of ventricular beta-adrenoceptor density in that model of hypertension was responsible, at least partially, for the lowered inotropic responsiveness of the same hearts to isoprenaline.
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PMID:Beta-adrenoceptors and responsiveness in cardiac hypertrophy associated with renal hypertension in renovascular hypertensive rats. 632 88

In these studies we have characterized differences between spontaneously hypertensive rats (SHR) and normotensive Wistar/Kyoto (WKY) rats with respect to rates of neuronal uptake of norepinephrine (NE) and dopamine (DA), and beta-adrenergic receptor (dihydroalprenolol; [3H]DHA) binding in the central nervous system. We find that SHR have greater rates of NE uptake in the frontal cortex, cerebellum, hypothalamus and pons-medulla during early development, and that these changes are accounted for, at least in the cerebral cortex, by an increased Vmax of the NE uptake mechanism. In addition, we find a decrease in the Bmax for [3H]DHA binding, suggestive of down-regulation of beta-adrenergic receptors of this region. In contrast to the results for NE uptake, we have measured significant decreases in DA uptake in the frontal cortex of the SHR at several postnatal ages. Decreases in DA uptake were also observed in the striatum of SHR although these changes were found only in animals approximately 6 weeks of age. From these results we have suggested that NE neurons projecting to a number of brain regions have elevated functional activity, while more regionally selective decreases in dopaminergic functional activity are characteristic of the SHR. We have further proposed that these changes in catecholamine neurons of the central nervous system may play an important role in the development of both the hypertension and behavioral hyperactivity exhibited by these animals.
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PMID:Changes in catecholamine neuronal uptake and receptor binding in the brains of spontaneously hypertensive rats (SHR). 728 59


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