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Query: UMLS:C0018801 (heart failure)
 72,216 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The relationship between energy metabolism and the extent of irreversible ischemic damage was examined in an isolated perfused working rat heart. The amount of cardiac work recovered after reperfusion of hearts exposed to severe global ischemia was dependent upon both the duration of ischemia and the type of substrate provided (either 5 mM glucose or 5 mM glucose + acetate). There appear to be two distinct phases in the ability to recover mechanical function in the reperfused ischemic heart. The second phase corresponds to the onset of severe irreversible tissue damage. Irreversible mitochondrial damage was not found to correspond with the onset of heart failure since the ATP/ADP ratio remained constant in the reperfused myocardium. Furthermore, there does not appear to be a direct correlation between the total ATP content and the extent of irreversible damage, either during ischemia or following reperfusion. However, the total adenine nucleotide content during ischemia showed dramatic changes which correspond temporally with the initiation of the second phase of damage. The observation that the adenine nucleotide pool becomes further depleted during reperfusion suggests that alterations in the salvage pathway for adenine nucleotide synthesis have occurred. Loss of adenine nucleotides appears to be an excellent marker for irreversible heart failure. Acetate provides some protection the the ischemic myocardium. The mechanism by which acetate mediates this protective effect is discussed.
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PMID:Relationship between adenine nucleotide metabolism and irreversible ischemic tissue damage in isolated perfused rat heart. 44 6

Hormonal, renal and blood pressure effects of SCH 39370, a selective inhibitor of neutral metalloendopeptidase (endopeptidase 24.11, NEP), were studied in a chronic, congestive heart failure (CHF) model produced by coronary artery ligation in the rat. Sham-operated control rats and rats with CHF were treated either with vehicle or SCH 39370, 30 mg/kg s.c. b.i.d. for 2.5 days. Plasma levels of atrial natriuretic peptide (ANP) and urinary excretion of cyclic GMP (cGMP) were clearly raised in rats with CHF as compared with controls during vehicle treatment. SCH 39370 caused a further increase in plasma ANP in CHF rats but not in control rats. Urinary excretion of immunoreactive ANP and cGMP increased during SCH 39370 treatment both in CHF rats and in controls. SCH 39370 treatment resulted in an initial increase in urine volume in rats with CHF whereas urine sodium excretion did not change significantly. No changes in renal function due to SCH 39370 treatment were seen in control rats. Systolic blood pressure, plasma renin activity and urine excretion of catecholamine metabolites (4-hydroxy-3-methoxyphenyl acetic acid and metanephrines) did not change during SCH 39370 treatment either in controls or in CHF rats. We conclude that the NEP-inhibitory compound SCH 39370 is capable of increasing plasma ANP concentration and urinary excretion of cGMP in rats with chronic CHF. In this severe heart failure model, the possible beneficial effects of additional ANP increments may be blunted, however. NEP inhibitors offer a novel approach to study the significance of ANP elevation in chronic CHF.
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PMID:Elevation of plasma atrial natriuretic peptide in rats with chronic heart failure by SCH 39370, a neutral metalloendopeptidase inhibitor. 214 36

In a prospective study of 103 patients with carcinoid tumors consecutively referred for medical treatment, the most common sites of the primary tumors were the ileum (73%), bronchi (7%), and jejunum (4%). All patients had local metastases, and 96 (93%) also had liver metastases. The most common initial symptoms were diarrhea (32%), ileus (25%), and flush (23%). The overall frequency of diarrhea was 84% and of flush was 75%. Heart insufficiency caused by cardiac valve disease was seen in 33% of the patients. The carcinoid syndrome, including flush, diarrhea, and elevated urinary 5-hydroxyindole acetic acid (5-HIAA) concentrations, was manifested by 69 patients (67%), 64 of whom (93%) had carcinoid tumors of mid-gut origin. Elevated urinary 5-HIAA was found in 91 patients (88%), of which 89 displayed liver metastases. The plasma concentration of the tachykinin neuropeptide K (NPK) was elevated in 67 patients (66%), 63 of whom had tumors of the mid-gut region. Serum pancreatic polypeptide (PP) and human chorionic gonadotrophin alpha levels were elevated in 43% and 28% of the patients, respectively, and the highest levels were found in patients with metastatic bronchial carcinoid tumors. Thirty-nine of the 103 patients are now dead; 18 died of tumor progression, whereas 14 patients died of heart failure secondary to a carcinoid tricuspidal valve insufficiency. The estimated median survival from the time of histologic diagnosis was 14 years, and from the time of carcinoid syndrome was 8 years.
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PMID:Malignant carcinoid tumors. An analysis of 103 patients with regard to tumor localization, hormone production, and survival. 244 Mar 90

The effects of gossypol acetic acid on isometric and isotonic contractions of isolated ferret heart ventricular muscle was recorded on a myograph. In isometric contractions, at the concentration range of 1-5 mcg/m1, gossypol inhibited peak force and maximum lengthening, at 0.63, 1.25 mM calcium levels. Gossypol had no effect on rate of tension rise. In isotonic contractions, gossypol also decreased the maximum shortening, but not the maximum rate of shortening. The results were interpreted in terms of reduction in numbers of crossbridges and amount of activator calcium available at the cell membrane for the muscle fibers, possibly contributing to the observed cases of cardiac failure.
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PMID:The direct negative inotropic effect of gossypol. 376 94

Eighteen patients with severe symptoms of the carcinoid syndrome were assessed for hepatic embolisation. Four were too ill, and one had mild symptoms; thus 13 received a periembolisation regimen of cyproheptadine, fenclonine, aprotinin, methylprednisolone, tobramycin, flucloxacillin, and metronidazole. Embolisation was not performed in one patient with an occluded portal vein and was unsatisfactory in two others, in one because she was moribund and in the other because the hepatic artery had been ligated. Dramatic improvement in symptoms occurred in the nine patients in whom embolisation was successfully carried out, with abolition of flushing, severe abdominal pain, and wheeze and reduction in diarrhoea from 10.5 (SD 7.6) to 1.6 (0.9) stools/day. Urinary excretion of 5-hydroxyindole acetic acid fell from 1048 (716) to 289 (184) mumol/24 h (200 (137) to 55 (35) mg/24 h). Complications included one death from septicaemia, a hepatic abscess requiring surgical drainage, abdominal pain in three patients, pleural effusion in two, and transient encephalopathy in one. Relief of symptoms lasted for one to 24 months, and second embolisation in two patients produced further remissions of four to six months. Five patients died, one to 40 months after embolisation, in four cases because of metastases or heart failure. Hepatic embolisation is the treatment of choice for symptoms of the carcinoid syndrome resistant to medical treatment.
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PMID:Role of hepatic arterial embolisation in the carcinoid syndrome. 641 93

Imidazoline receptors were identified in cardiac tissues of various species. Imidazoline receptors were immunolocalized in the rat heart. Membrane binding and autoradiography on frozen heart sections using 0.5 nM para-iodoclonidine (125I-PIC) revealed that binding was equally and concentration-dependently inhibited by epinephrine and imidazole-4-acetic acid (IAA), implying 125I-PIC binding to cardiac alpha2-adrenergic and I1-receptors, respectively. After irreversible blockade of alpha2-adrenergic receptors, binding was inhibited by the selective I1-agonist, moxonidine, and the I1-antagonist, efaroxan, in a concentration-dependent (10-12 to 10-5 M) manner. Calculation of kinetic parameters revealed that in canine left and right atria, I1-receptor Bmax was 13.4 +/- 1.7 and 20.1 +/- 3.0 fmol/mg protein, respectively. Compared to age-matched normotensive Wistar Kyoto rats, I1-receptors were increased in 12-week-old hypertensive rat (SHR) right (22.6 +/- 0.3 to 43.7 +/- 4.4 fmol/unit area, p < 0.01) and left atria (13.3 +/- 0.6 to 30.2 +/- 4.1 fmol/unit area, p < 0.01). Also, compared to corresponding normal controls, Bmax was increased in hearts of hamsters with advanced cardiomyopathy (13.9 +/- 0.4 to. 26.0 +/- 2.3 fmol/unit area, p < 0.01) and in human ventricles with heart failure (12.6 +/- 1.3 to 35.5 +/- 2.9 fmol/mg protein, p < 0.003). These studies demonstrate that the heart possesses imidazoline I1-receptors that are up-regulated in the presence of hypertension or heart failure, which would suggest their involvement in cardiovascular regulation.
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PMID:Imidazoline receptors in the heart: characterization, distribution, and regulation. 1202 82

This case report concerns a hemodialysis patient with arrhythmia. A 71-year-old man had undergone hemodiafiltration (HDF) for 17 years for the treatment of chronic glomerulonephritis. Because of repeated heart failure and chronic atrial fibrillation, he could not continue receiving standard hemodialysis, which is hemodialysis using bicarbonate dialysate including a small amount of acetate. Neither elevating the sodium concentration of the dialysate nor changing the HDF modality was effective. Acetate-free biofiltration (AFB) was initiated and this treatment dramatically ameliorated the patient's intradialytic acute hypotension and arrhythmia. The patient's quality of life subsequently improved and his scores on the Short-form 36 questionnaire (a measure of quality of life) increased. AFB is an HDF technique based on the continuous postdilution infusion of a sterile isotonic bicarbonate solution. Previous studies have reported that acetate induces chemical cytokines and vasodilator substances. AFB may be effective for preventing acute hypotension and arrhythmia during dialysis and may improve quality of life, including mental status.
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PMID:A case report of the effect of acetate-free biofiltration on arrhythmia in a hemodialysis patient. 1738 38

It has been demonstrated that hypertension can lead to coronary heart disease, heart failure, stroke, and memory loss. In this study we investigated the effect of acute and chronic hypertension on the avoidance and spatial learning and memory in rats. The forty male rats were divided into acute hypertensive, chronic hypertensive and control for each group rats. Hypertension was induced by Deoxy Corticosterone Acetate (DOCA)-salt method. DOCA was injected 30mg/kg of body weight subcutaneously, twice a week. These rats received NaCl 1% instead of tap water for drinking throughout the experiment. The control group received normal saline injection with usual drinking water. Spatial learning and memory was investigated by Morris water maze test and passive avoidance learning by Shuttle box test in the rats after hypertension induction. Results showed that acute hypertension impaired short-term memory in passive avoidance learning. However, acute and chronic hypertension did not affect spatial learning and memory. These data suggest that simple uncomplicated hypertension does not remarkably alter cognition.
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PMID:Effect of acute and chronic hypertension on short- and long-term spatial and avoidance memory in male rats. 1976 67

Human mitochondrial acetaldehyde dehydrogenase 2 (ALDH2) catalyzes the oxidation of acetaldehyde to acetic acid. Therefore, ALDH2 has therapeutic potential in detoxification of acetaldehyde. Furthermore, ALDH2 catalyzes nitroglycerin to nitrate and 1, 2-glyceryldinitrate during therapy for angina pectoris, myocardial infarction, and heart failure. Large quantities of ALDH2 will be needed for potential clinical practice. In this study, Pichia pastoris was used as a platform for expression of human ALDH2. Based on the ALDH2*1 cDNA sequence, we designed ALDH2 cDNA by choosing the P. pastoris preferred codons and by decreasing the G + C content level. The sequence was synthesized using the overlap extension PCR method. The cDNA and 6xHis tags were subcloned into the plasmid pPIC9K. The recombinant protein was expressed in P. pastoris GS115 and purified using Ni(2+)-Sepharose affinity chromatography. The amount of secreted protein in the culture was 80 mg/L in shake-flask cultivation and 260 mg/L in high-density bioreactor fermentation. Secreted ALDH2 was easily purified from the culture supernatant by using Ni(2+)-Sepharose affinity chromatography. After purification of the fermentation supernatant, the enzyme had a specific activity of 1.2 U/mg protein. The yield was about 16 mg/L in a shake flask culture of P. pastoris GS115 which contained the original human ALDH2*1 cDNA.
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PMID:Efficient expression of codon-adapted human acetaldehyde dehydrogenase 2 cDNA with 6xHis tag in Pichia pastoris. 1991 Nov 29

The Ca(2+) dependent interaction between troponin I (cTnI) and troponin C (cTnC) triggers contraction in heart muscle. Heart failure is characterized by a decrease in cardiac output, and compounds that increase the sensitivity of cardiac muscle to Ca(2+) have therapeutic potential. The Ca(2+)-sensitizer, levosimendan, targets cTnC; however, detailed understanding of its mechanism has been obscured by its instability. In order to understand how this class of positive inotropes function, we investigated the mode of action of two fluorine containing novel analogs of levosimendan; 2',4'-difluoro(1,1'-biphenyl)-4-yloxy acetic acid (dfbp-o) and 2',4'-difluoro(1,1'-biphenyl)-4-yl acetic acid (dfbp). The affinities of dfbp and dfbp-o for the regulatory domain of cTnC were measured in the absence and presence of cTnI by NMR spectroscopy, and dfbp-o was found to bind more strongly than dfbp. Dfbp-o also increased the affinity of cTnI for cTnC. Dfbp-o increased the Ca(2+)-sensitivity of demembranated cardiac trabeculae in a manner similar to levosimendan. The high resolution NMR solution structure of the cTnC-cTnI-dfbp-o ternary complex showed that dfbp-o bound at the hydrophobic interface formed by cTnC and cTnI making critical interactions with residues such as Arg147 of cTnI. In the absence of cTnI, docking localized dfbp-o to the same position in the hydrophobic groove of cTnC. The structural and functional data reveal that the levosimendan class of Ca(2+)-sensitizers work by binding to the regulatory domain of cTnC and stabilizing the pivotal cTnC-cTnI regulatory unit via a network of hydrophobic and electrostatic interactions, in contrast to the destabilizing effects of antagonists such as W7 at the same interface.
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PMID:A structural and functional perspective into the mechanism of Ca2+-sensitizers that target the cardiac troponin complex. 2080 Nov 30


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