Carnitine levels in patients with chronic rheumatic heart disease.
ABSTRACT Carnitine, a small aminoacid derivative plays a major role in fatty acid oxidation. Myocardial carnitine deficiency may cause malfunction of the heart. Rheumatic valvular heart disease can be associated with myocardial dysfunction. We have investigated myocardial and plasma-free carnitine levels in patients with chronic rheumatic heart disease.
Eleven patients with chronic rheumatic heart disease requiring valve replacement were selected for study. Ten patients with no cardiac failure, myocardial wall motion abnormalities and myocardial infarction and for whom coronary bypass surgery was planned were selected as the control group. Carnitine levels of myocardial tissue obtained from the right atrium and plasma during the operation were evaluated using spectrophotometric method. Myocardial-free carnitine levels expressed as mumol/g (dry weight) were determined according to Ceberblad and Lindstedt technique.
Myocardial-free carnitine levels in patients were found to be 0.72 +/- 0.37 mumol/g (dry weight) in comparison with 1.44 +/- 1.03 mumol/g (dry weight) in the control group. Myocardial-free carnitine levels in patients were statistically decreased when compared to control group. Plasma-free carnitine levels in patients were 80.91 +/- 28.22 mumol/L and 89.52 +/- 48.21 mumol/L in the control group, respectively. There was no significant difference between plasma-free carnitine levels of the groups.
In our study, myocardial-free carnitine levels were decreased while plasma-free carnitine levels were normal in patient with chronic rheumatic heart disease.
Article: Carnitine and cardiac interstitium.[show abstract] [hide abstract]
ABSTRACT: An important part of (acyl)carnitine may be stored in interstitial spaces and the external surface of adjacent cells. A high concentration of carnitine in the direct vicinity of cells may enhance the synthesis and export of long-chain acylcarnitine. Long-chain acylcoenzyme A, from which long-chain acyl carnitine is formed, cannot penetrate intact cell membranes. During hypoperfusion or ischemia, when long-chain acylcoenzyme A accumulates due to hampered fatty acid oxidation, there is an increased formation of long-chain acyl carnitine which diffuses into the interstitium and adjacent vascular endothelial cells. Due to its lipophilic nature and net positive charge (limitation of carboxyl-group dissociation in ischemic acidosis), long-chain acyl carnitine may decrease the affinity of Ca2+ to the cell surface and prevent Ca2+ overload of cells. The advantage of carnitine over many other cationic amphiphiles in the protection of areas of ischemia is that long-chain acyl carnitine is formed and stored only in ischemic areas.Cardioscience 07/1994; 5(2):67-72.
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ABSTRACT: Carnitine, an essential cofactor in fatty acid oxidation, plays a central role in myocardial metabolism. Interpretation of the biochemical features of disturbed myocardial function, particularly in ischemia, may be facilitated by understanding carnitine biosynthesis, transport and function. Biosynthesis: In man, deoxycarnitine, the immediate precursor of carnitine, is synthesized in all tissues, whereas the last step, the conversion of deoxycarnitine into carnitine may only take place in liver, kidney and brain (Figs. 1 and 2). Deoxycarnitine formed by organs like muscle or heart is released into the plasma, taken up by liver and kidney, converted into carnitine which is secreted into the bloodstream to be taken up by heart or muscle (Fig. 2). Carnitine transport and cellular function: The myocardial uptake of carnitine against a large concentration gradient (Table 1) occurs in an 1:1 exchange-diffusion process. Under physiological conditions, intracellular deoxycarnitine is exported and extracellular carnitine is imported. According to this model, myocardial carnitine deficiency may be due either to a functional alteration of the sarcolemmal carnitine carrier or to a deficient synthesis of deoxycarnitine. D-carnitine, acetylcarnitine and long-chain acylcarnitine esters are also transported by the carrier at different rates. This might account for the release of endogenous acylcarnitines accumulated in anoxic or ischemic conditions, contributing to the cardioprotective effect of carnitine by reduction in intracellular long-chain acyl-coenzyme A.(ABSTRACT TRUNCATED AT 250 WORDS)Zeitschrift für Kardiologie 02/1987; 76 Suppl 5:34-40. · 0.97 Impact Factor
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ABSTRACT: The distribution of CD3+, CD4+, CD8+, CD19+, CD16+, and CD25+ lymphocyte populations in peripheral blood as well as the plasma concentrations of interleukin-1 alpha (IL-1 alpha), and IL-2 and tumor necrosis factor alpha (TNF-alpha) were investigated in 25 children with acute rheumatic fever (ARF) at the time of admission and after 3 months and in 15 children with chronic rheumatic heart disease (CRHD) and in 15 children with streptoccocal pharyngitis (SP) in order to determine changes in lymphocyte subsets and cytokine concentrations occurring during different stages of the disease. The percentages and absolute counts of CD4+, CD16+, CD25+ cells, the ration of CD4/CD8 and plasma concentrations of IL-1 alpha and IL-2 in patients with ARF were significantly higher at admission than 3 months later. These levels were also significantly higher than in patients with CRHD, SP, or normal controls. Production of IL-2 in ARF and CRHD patients directly correlated with the percentages of CD4+ and CD25+ cells. According to our results, the evidences of increased cellular immune response in ARF are increased percentages CD4+ and CD25+ cells, CD4/CD8 ratio, and increased plasma concentrations of IL-1 alpha and IL-2. Furthermore, activation of cellular immune response was not present throughout all stages of rheumatic heart disease and also in SP.Clinical Immunology and Immunopathology 12/1995; 77(2):172-6.