摘要:

This bibliography is produced in association withCurrent Opinion in Cardiology(Current Science Ltd, UK) and is compiled from over 150 journals (these are listed at the end of the bibliography in this issue). Each issue of theJournal of Hypertensionlists papers relevant to hypertension, published over a one-month period. A cumulative bibliography, covering 12 months and arranged under subject headings, appears in the first issue (January) each year. A complete, updated list of the journals scanned is published at the same time as the cumulative bibliography.

ISSN:0263-6352    

出版商:OVID    

年代:1989

数据来源: OVID

ISSN:0263-6352    

出版商:OVID    

年代:1989

数据来源: OVID

ISSN:0263-6352    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

We have studied the effect of dietary NaCl loading on renin gene expression in one-gene, two-gene and transgenic mouse strains. By Northern blotting, we found an approximate twofold reduction in renin messenger (m) RNA in the kidneys of high-NaCl-treated compared with low-NaCl-treated animals. Using an RNase-protection assay designed to discriminate between the different renin gene transcripts, we have shown that renin mRNAs derived from theRen-1cgene of one-gene strains and theRen-1DandRen-2 genes of two-gene animals are all NaCl-responsive. Renin mRNA derived from a 19 kilobaseRen-1Dtransgene is also NaCl-responsive.

ISSN:0263-6352    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

We have explored the role of the kallikrein—kinin system in essential hypertension using spontaneously hypertensive rats (SHR) as an animal model. A rat tissue kallikrein complementary (c) DNA (RSK 1105) was used as a probe in Southern blot hybridization to detect restriction fragment length polymorphisms (RFLPs) in SHR. Using 23 different restriction endonucleases, we have identified five RFLPs involving alterations in restriction fragment lengths for the restriction enzymesBglII, Dra I, Nde I, Sph I, and Bcl l. Three of the enzymes, Nde I, Sph I, and Bgl II, generate multiple polymorphic fragments. We have further mapped these RFLPs with two additional probes, both from the rat renal kallikrein gene RSKG 7. The 5' probe, consisting of sequences approximately 2000 base pair (bp) 5' of the first exon, recognizes RFLPs in DNA digested with Bel I and Sph I. The 3' probe, approximately 4400 bp away from the fifth exon, recognizes polymorphic fragments in DNA digested with Bel I, Dra I and Nde I. These findings indicate possible differences in tissue kallikrein genes or their regulatory regions in SHR that could contribute to the pathogenesis of hypertension in this animal model.

ISSN:0263-6352    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

The characterization of α-adrenoceptor-mediated contractile responses and the effects of the calcium channel blocker nifedipine on these responses were investigated in mesenteric arterial strips from 13-week-old male spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto rats (WKY). Contractile responses to the alpha;-adrenoceptor agonists phenylephrine and clonidine were mediated through the activation of α1-adrenoceptors. The dose producing a half-maximum response (ED50) for the agonists was higher in SHR than in WKY. Affinities of α1-adrenoceptors were similar between the two strains. When arterial strips from both strains were treated with the same concentration of phenoxybenzamine, the maximum response to each agonist was weaker in SHR. The α1-adrenoceptor occupancy-response relationship for phenylephrine was hyperbolic and less steep in SHR, while the relationship for clonidine was linear in SHR but not in WKY. Alpha1-adrenoceptor occupancy at a half-maximum response to each agonist was greater in SHR. Nifedipine inhibited the maximum responses to the agonists more profoundly in SHR than in WKY. This inhibition was greater in the response to clonidine than in the response to phenylephrine in both strains. When the maximum response to phenylephrine was reduced to the same extent in both strains by treatment with different concentrations of phenoxybenzamine, the responses to phenylephrine were more susceptible to inhibition by nifedipine. Under these conditions, the effects of nifedipine were similar between SHR and WKY. These results suggest that α1-adrenoceptor reserve is reduced in SHR mesenteric artery compared with WKY, which may be responsible for the greater inhibition by nifedipine of the α1-adrenoceptor-mediated contractions in SHR.

ISSN:0263-6352    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

An exaggerated reflex response of forearm resistance vessels following stimulation of cardiac mechanoreceptors has been observed in human hypertension. In the present study we analyze the possibility that such an increased response also involves the large brachial artery. For that purpose, the influence of leg elevation in subjects in a supine position on brachial artery diameter and blood flow velocity was studied in 12 healthy, normal males and 17 males of the same age with sustained essential hypertension. Brachial artery diameter and blood flow velocity were measured using a two-dimensional pulsed Doppler velocimeter, with subjects in a supine horizontal position, after passive elevation of the legs and again in a supine horizontal position. Blood pressure and heart rate remained unchanged throughout the study. Elevation of the legs induced an immediate increase in brachial artery diameter (P<0.001) and blood flow velocity (P<0.001) in both normal subjects and hypertensive patients. The maximal increase in these two parameters was similar in the two groups. In normal subjects, the increases were short-lived, with values returning to baseline levels even when leg elevation was maintained. In hypertensive patients, the increases persisted throughout the period of leg elevation, and brachial artery diameter remained significantly increased in comparison with normal subjects (P<0.01). This study provides evidence that loading cardiac mechanoreceptors causes a large dilation of the conduit arteries which is long-lasting in essential hypertensives and short-lived in normal subjects.

ISSN:0263-6352    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

In this study, previously untreated subjects were randomly recruited from a blood pressure screening programme. After repeated measurement of blood pressure levels, the subjects were divided into three groups: normotensives (n = 95), borderline hypertensives (n = 69) and hypertensives (n = 30). Three self-administered standardized questionnaires were used to measure different aspects of subjective well-being and symptoms: the Nottingham Health Profile (NHP), the Subjective Symptoms Assessment Profile (SSAP) and the Minor Symptoms Evaluation Profile (MSEP). The results indicate gradual differences between the three groups, the most pronounced symptoms being seen among the hypertensives. Statistically significant differences were found for cardiac and gastrointestinal symptoms as well as for emotional reactions, home life, social life, sex life and sleep.The differences in well-being and subjective symptoms noted between the groups are important in the evaluation of new antihypertensive agents. Self-administered questionnaires of the type used in this study could also be valuable in identifying symptoms and disturbances in subjective well-being related to the antihypertensive medicationper se.

ISSN:0263-6352    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

Reversal of one-kidney, one clip (1-K, 1C) hypertension by removal of the renal artery clip is accompanied by increased renal and vascular prostaglandin (PG) production. It was postulated that PG biosynthesis is stimulated in the unclipped hypertensive kidney. In order to test this hypothesis, we compared urinary excretion of PGE2and 6-keto-PGF1α(a breakdown product of PGI2) in perfused kidneys isolated from 1-K, 1C hypertensive rats, 1-K, sham-clipped rats and 1-K, 1C rats which had failed to become hypertensive. Urine was collected over 15 min periods at perfusion pressures of 100, 150 and 200mmHg. At perfusion pressures of 100 and 150mmHg there was no significant difference in PGE2excretion between the three groups. In contrast, 6-keto-PGF1αexcretion at 150mmHg was higher in the hypertensive rats compared with the sham-clipped (P<0.05) and failed hypertensive (P<0.01) rats. At 200 mmHg, both PGE2and 6-keto-PGF1αwere significantly higher in the hypertensive rats than in the control groups. These increases in PG excretion were clearly dissociated from changes in urinary flow rates. The findings support the hypothesis of increased synthesis of renal vasodilatory and natriuretic PGs in 1-K,1C hypertension which is particularly evident at higher perfusion pressures, such as may be encountered when the hypertensive kidney is unclipped and exposed to high arterial pressure.

ISSN:0263-6352    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

In this study, β-adrenergic receptors of cultured arterial smooth muscle cells (ASMC) from normotensive Wistar—Kyoto rats (WKY) and spontaneously hypertensive rats (SHR) were compared. Scatchard analysis of [3H]-dihydroalprenolol hydrochloride (DHA) binding revealed that the maximum binding capacity (Bmax) for [3H]-DHA binding was significantly higher in WKY than in SHR, by twofold (n=6,P<0.0001). Analysis of isoproterenol competition for [3H]-DHA binding by computerized non-linear regression indicated that the two strains have an equal number of high-affinity-state receptors, but that WKY rats have about three times more low-affinity-state receptors than SHR. Isoproterenol stimulated cyclic adenosine monophosphate (cAMP) production in a dose-dependent manner, and dose—response experiments revealed an effective concentration of ligand at which 50% of the maximum effect is observed (EC50) of 5-10 x 10−8mol/l isoproterenol for both WKY and SHR. Also, isoproterenol-stimulated cAMP production was inhibited by propranolol in a dose-dependent manner.This study demonstrates that the previously described difference observed for in vivo binding of β-adrenergic receptors of vessels from SHR is retained in tissue culture of vascular smooth muscle and is, therefore, independent of the elevated plasma catecholamine and blood pressure levels found in SHR. The finding that there is equal cAMP stimulation in WKY and SHR is consistent with the discovery of an equal number of high-affinity-state receptors in the two strains. The difference in total β-adrenergic receptor number is secondary to the greater number of low-affinity-state receptors found in WKY.

ISSN:0263-6352    

出版商:OVID    

年代:1989

数据来源: OVID