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)

The appropriate use of any test requires the clinician to appreciate that test's limitations. By recognizing the potential confounders of the auscultatory assessment of blood pressure, the clinician minimizes the likelihood of enacting therapeutic decisions based on inaccurate data. When approaching the treatment of a hypertensive patient, several points should be kept in mind. First, the measurement of persistent and severe hypertension in a patient receiving treatment who describes symptoms of orthostatic hypotension with apparently adequate standing blood pressure or who lacks corroborating retinal, echocardiographic, or electrocardiographic signs of hypertension should raise the concern of pseudohypertension or a white-coat response. Similarly, when one finds a normal or near-normal systolic blood pressure in a patient with a clinical picture consistent with severe hypertension, one should make a directed effort to look for an unrecognized auscultatory gap. Second, marked discrepancies in measurements as obtained by different operators or in different settings should raise concern of the white-coat response or methodologic errors by one operator, such as undercuffing, excessive pressure on the head of the stethoscope, rapid deflation of the cuff, or use of different arms. In treating hypertension in even the minimally obese patient, a special point must be made that an adequate size cuff be used for all blood pressure determinations. Third, when blood pressure is determined with the patient in any but the satndardized back-and-arm-supported seated position described above, the clinician should acknowledge the possibility that the position may alter the patient's classification. Fourth, the diagnosis and management of hypertension requires multiple measurements of blood pressure.(ABSTRACT TRUNCATED AT 250 WORDS)
J Gen Intern Med 1995 Apr
PMID:Confounders of auscultatory blood pressure measurement. 779 Sep 85

1. The effects of phenoxybenzamine treatment on the contractile responses of the aorta from WKY and SH rats to noradrenaline and adrenaline have been determined. 2. There was no change in sensitivity of the aorta to noradrenaline or adrenaline with hypertension. 3. Phenoxybenzamine treatment caused nonparallel rightward shifts of the concentration-response curves to the lower concentrations of noradrenaline and adrenaline. 4. The KA value for noradrenaline on the WKY rat aorta was 4.15 x 10(-8) M and noradrenaline produced a 95% maximum response by occupying 95% of the available alpha 1-adrenoceptors. These parameters were significantly different on the SH rat aorta; thus the KA value for noradrenaline was 76.40 x 10(-8) M and noradrenaline produced a 95% maximum response by occupying 63% of the alpha 1-adrenoceptors. 5. The KA value for adrenaline on the WKY rat aorta was 5.03 x 10(-8) M and adrenaline produced a 95% maximum response by occupying 95% of the available alpha 1-adrenoceptors. These adrenaline parameters were not significantly different on the SH rat aorta. 6. In summary this study has demonstrated that although the sensitivities of the rat aorta to noradrenaline and adrenaline do not alter, there is a change in the KA and receptor reserve for noradrenaline, but not adrenaline in hypertension.
Gen Pharmacol 1994 Sep
PMID:Characterization of the contractile responses to noradrenaline and adrenaline of aorta from normotensive and hypertensive rats. 783 16

1. The role of the endothelium on the constrictor effect of noradrenaline (NA), and endothelium-dependent and endothelium-independent vasodilator effects of different agonists were determined in rings of aortae obtained from nondiabetic (control), non-insulin-dependent (NID-) diabetic and NID-diabetic rats treated with insulin. 2. The NA-induced contractions are markedly increased with no change in agonist potency (pD2 value) in aortae with intact endothelium obtained from NID-diabetic rats when compared to those from age-matched controls. Mechanical removal of the endothelium resulted in a significant increase in maximum contractile response of control aortae but not NID-diabetic aortae to NA relative to presence of endothelium. No significant difference was observed between the contractile responses of NID-diabetic and control aortae to NA after the removal of endothelium. 3. Endothelium-dependent relaxations elicited by acetylcholine (ACh), histamine, ATP and insulin strongly depressed in NID-diabetic aortae but the relaxations stimulated by sodium nitroprusside (SNP) did not change when compared to corresponding controls. There was no significant changes in the pD2 values calculated by agonist-induced relaxations of aortae from either untreated or insulin-treated NID-diabetic rats compared with controls. 4. NID-diabetes-induced alterations on the reactivity of aortae were significantly restored by in vivo insulin treatment. 5. These data indicate that impaired endothelium-dependent vasodilatory responses of aortae from NID-diabetic rats results in increased NA-induced contractions. It is possible that, impaired endothelium-dependent vasodilatory modulation of vasoconstriction may play a important role in development of vasospasm and hypertension in NID-diabetics.
Gen Pharmacol 1994 Jul
PMID:The role of the endothelium on enhanced contractile response of non-insulin-dependent diabetic rat aortae: effects of insulin treatment. 795 44

I have discussed the pharmacokinetics, efficacies, and side effects of the various nonnarcotic drugs available for the treatment of patients who have headache. Sumatriptan, the newest one, is expensive but may be cost-effective for those who have failed traditional migraine treatment, who visit the ER frequently, who have potential for drug abuse, or who have to miss time from school or work due to the headache. Studies are in progress to compare sumatriptan with other available drugs such as DHE-45 and to determine its possible role in the prophylaxis of migraine. A new 5-HT1D receptor agonist with more efficacy and fewer side effects may be developed in the future. When sumatriptan and DHE-45 are contraindicated due to hypertension or coronary artery disease, other drugs such as metoclopramide, ketorolac, and butorphanol can be used as alternatives.
J Gen Intern Med 1994 Jun
PMID:Recent advances in the acute management of migraine and cluster headaches. 807

1. A comparison of the effects of various opioid peptides on the heart rates of self-paced right atria was made, as taken from spontaneously hypertensive (SHR), Wistar Kyoto (WKY) and Sprague-Dawley (SD) rats at 4, 8, 12 and 16 weeks of age. 2. Beta-endorphin, dynorphin, met-enkephalin, DAGO and DADLE slightly decreased the spontaneously beating rate of all rat strains and ages, at 0.1 microM. Leu-enkephalin at 0.2 microM increased the spontaneous beating rate of SHR atria, but not that of atria from normotensive strains. 3. SHR atria were somewhat more sensitive than WKY atria to norepinephrine (NE)-induced positive chronotropy, but the differences were not statistically significant. 4. In the presence of mu, delta or kappa opioid receptor agonists, SHR atrial sensitivity to NE-induced chronotropy was enhanced at all ages studied. By contrast, NE chronotropy was not significantly altered by the opioids in normotensive rat atria. 5. Based on the above results, all the three major opioid receptor subtypes (mu, delta and kappa) appear to be present in rat atria but the function of these receptors appears to be greater in SHR than in WKY and SD atria. 6. The results suggest a possible involvement of altered opioid responsiveness in atria during hypertension development in SHR but the nature of this involvement appears to be complex and is not readily understandable on the basis of the present study.
Gen Pharmacol 1993 Nov
PMID:Possible opioid receptor function changes in isolated atria of the spontaneously hypertensive rat. 811 24

1. Neuropeptide Y (NPY) occurs in both the central and peripheral nervous system. In the periphery, NPY coexists with noradrenaline (NA) in perivascular sympathetic fibers. 2. NPY has a vasopressor effect, reflecting direct vasoconstriction of blood vessels and potentiation of the NA-evoked response. NPY also suppresses the release of NA from sympathetic fibers. 3. The post- and pre-junctional NPY receptors are referred to as Y1 and Y2, respectively. They recognize not only NPY but also the homologous gut hormone peptide YY (PYY). 4. The Y1 and Y2 receptors have been characterized in numerous test systems using analogs of NPY/PYY. Already the deletion of the first N-terminal amino acid (NPY 2-36) results in a marked loss of potency at the Y1 receptor. The Y2 receptor is much less dependent upon an intact N-terminus, and a wide range of C-terminal NPY fragments retain quite high potency. 5. Recently, yet another NPY receptor, Y3, that is distinct from Y1 and Y2 in that it recognizes PYY poorly, has been demonstrated in the brainstem and in the periphery. 6. Further attempts to characterize the various receptor types have relied on truncated and substituted analogs of NPY/PYY. Although such studies suggest the existence of at least three types of NPY receptors, the lack of antagonists has represented a problem. 7. Since NPY may regulate cardiovascular functions via peripheral and central receptors its physiological and possibly pathophysiological significance has attracted much attention. 8. The responsiveness to NPY seems to be altered in animal models of hypertension and elevated plasma levels of NPY have been found in patients under various conditions of stress and in primary hypertension. A number of studies have suggested that NPY may be a pathogenetic factor behind primary hypertension. 9. Antagonists for the various NPY receptors would be useful for an analysis of which effects of these peptides are physiologically relevant. It is tempting to predict that both agonists and antagonists of the NPY receptors could be useful as drugs, for instance, in the treatment of primary hypertension.
Gen Pharmacol 1993 Jul
PMID:Multiple neuropeptide Y receptors are involved in cardiovascular regulation. Peripheral and central mechanisms. 822 32

The authors used the N-of-1 clinical trial methodology to obtain insights about a patient's preference for garlic for the management of his hypertension. The 61-year-old man received garlic, 500 mg by mouth three times a day (3 weeks), or identical placebo (3 weeks) in three treatment pairs. While the patient was taking garlic the mean systolic blood pressure decreased by 2 mm Hg (95% confidence interval 0.4 to 4.7, p < 0.05), and the diastolic blood pressure decreased by 2.4 mm Hg (95% confidence interval 0.4 to 4, p < 0.025). The treatment effect of garlic was small, but the patient believed continuing garlic for the management of his hypertension was justified.
J Gen Intern Med 1993 Nov
PMID:Patient preferences for novel therapy: an N-of-1 trial of garlic in the treatment for hypertension. 828 3

1. In this study, the maximal contractile responses to noradrenaline (NA) were significantly increased but pD2 values (sensitivity) were not significantly altered in aortas with endothelium from insulin-dependent (ID)-diabetic rats when compared to their controls. 2. Removal of the endothelium resulted in a significant increase in the maximum response of control and ID-diabetic aortas and also loss of the difference in maximum contractile response to NA between ID-diabetic aortas and their corresponding controls. 3. Endothelium-dependent relaxation stimulated by acetylcholine (ACh), methacholine, histamine, ATP and insulin, in aortic rings precontracted with NA were significantly attenuated but unchanged by A23187 in ID-diabetic vessels relative to controls. 4. Relaxations produced by sodium nitroprusside (SNP) in ID-diabetic aortas were similar to those in control vessels. 5. The sensitivity of ID-diabetic aortas to relaxant substances were not changed when compared with controls. 6. These results demonstrate that ID-diabetes-induced specific changes in vascular reactivity and endothelial cells have an important role on the maintenance of vascular tonus. This feature may be responsible for the major complications of diabetes such as macroangiopathy, vasospasm and high blood pressure in late stage of the disease.
Gen Pharmacol 1993 May
PMID:The role of endothelial cells on the alterations in vascular reactivity induced by insulin-dependent diabetes mellitus: effects of insulin treatment. 836 55

1. Bradykinin and related kinins may act on four types of receptors designated as B1, B2, B3 and B4. It seems that the B2 receptors are most commonly found in various vascular and non-vascular smooth muscles, whereas B1 receptors are formed in vitro during trauma, and injury, and are found in bone tissues. 2. These BK receptors are involved in the regulations of various physiological and pathological processes. 3. The mode of kinin actions are based upon the interactions between the kinin and their specific receptors, which can lead to activation of several second-messenger systems. 4. Recently, numerous BK receptors antagonists have been synthesized with prime aim to treat diseases caused by excessive kinin production. 5. These diseases are RA, inflammatory diseases of the bowel, asthma, rhinitis and sore throat, allergic reactions, pain, inflammatory skin disorders, endotoxin and anaphylactic shock and coronary heart diseases. 6. On the other hand, BK receptor antagonists could be contraindicated in hypertension, since these drugs may antagonize the antihypertensive therapy and/or may trigger the hypertensive crisis. 7. It is worth suggesting that the BK receptor agonists might be useful antihypertensive drugs.
Gen Pharmacol 1993 Mar
PMID:Therapeutic prospects of bradykinin receptor antagonists. 838 49

Some eight years ago it was found that certain smooth muscle relaxants exert their effect by opening a specific K+ channel resulting in cell membrane hyperpolarization. The use of K+ channel openers (cromakalim, pinacidil and RP-52891) and compounds which antagonize their actions (glibenclamide, phentolamine and alinidine) has enabled a great deal of research to be performed into the role of this K+ channel, not only in smooth muscle, but also in cardiac and skeletal muscle as well as neural and endocrine organ function. Much of the attention has centred on the smooth muscle relaxant actions of the K+ channel openers, since they have potential therapeutic use in disorders involving smooth muscle over-reactivity such as hypertension and asthma. More recently the cardiac actions of the K+ channel openers have become the focus of interest. Although there appear to be good theoretical reasons why K+ channel openers may be of use in some arrhythmias and in ischaemic heart disease there are major hurdles to overcome. In particular, given that the effect of these compounds on vascular smooth muscle occurs at a concentration 20- to 100-fold lower than that required to produce cardiac effects, it is likely their therapeutic usefulness will be limited until a breakthrough in cardiac/vascular selectivity is made. There is also growing interest in endogenous K+ channel openers and the physiological role of the K+ channel which they open. Opening of K+ channels, either spontaneously or by endogenous regulators, could possibly be an important hypotensive mechanism both under normal conditions and in a number of pathological conditions.(ABSTRACT TRUNCATED AT 250 WORDS)
Gen Pharmacol 1993 Mar
PMID:Current trends in the study of potassium channel openers. 848 11


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