Abstract
Since fish hearts are resistant to the effects of hypoxia, comparison of the effects of hypoxia and ischaemia on fish and mammalian hearts may lead to better understanding of ischaemic injury in mammalian hearts. The ultrastructure and levels of ATP, creatine phosphate, and lactic acid were examined in hearts obtained from largemouth bass. Bass hearts were subjected to conditions of normoxia, ischaemia, hypoxia, and hypoxia in the presence of fluoride and cyanide. ATP levels remained stable during hypoxia and ischaemia, but fell during hypoxia in the presence of fluoride or fluoride plus cyanide. Changes in creatine phosphate and lactic acid indicated ATP was produced during hypoxia and ischaemia by glycolysis, by rephosphorylation from creatine phosphate, and by oxidative phosphorylation with oxygen obtained from myoglobin or the atmosphere. Ultrastructural changes were found similar to those reported in ischaemic mammalian heart, consisting of inter- and intracellular swelling, glycogen depletion, and mitochondrial alterations. Comparison of metabolic rates between fish and mammalian hearts suggests the lower rate in fish hearts may be the chief factor which permits stable ATP levels during hypoxia and ischaemia, and thus provides resistance to these conditions.
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Fluoride stimulates in vitro vascular prostacyclin synthesis: interrelationship of G proteins and protein kinase C
The role of G proteins in mediating adrenoceptor-prostacyclin synthesis coupling was investigated using the G protein activator, sodium fluoride. Sodium fluoride (NaF) stimulated in vitro rat aortic prostacyclin (PGI2) synthesis (EC50 = 5 x 10(-3) mol.l-1), an action inhibited completely by the presence of EDTA (10(-2) mol.l-1). The NaF-PGI2 dose-response
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Alterations in plasma and tissue acetylcholinesterase activity following repeated oral exposure of chlorpyrifos alone and in conjunction with fluoride in Wistar Rats
Concurrent exposures of more than one environmental contaminants are commonly encountered by human beings and animals. This study investigated the effect of chlorpyrifos alone and in conjunction with fluoride on plasma and tissue acetylcholinesterase (AChE) activity in wistar rats. Fluoride at 1 or 10 ppm in drinking water produced significant (P < 0.05)
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Fluoride in drinking water and intracardiac blood flow defects in Iowa
The relation between fluoride level in drinking water and the incidence of congenital heart disease in Iowa was studied by means of a hybrid case-control design. Controls (n = 2,172) were randomly selected from the birth tapes of the State of Iowa between January 1, 1983 and December 31, 1987,
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Effect of water fluoridation on the development of medial vascular calcification in uremic rats
Public water fluoridation is a common policy for improving dental health. Fluoride replaces the hydroxyls of hydroxyapatite, thereby improving the strength of tooth enamel, but this process can also occur in other active calcifications. This paper studies the effects of water fluoridation during the course of vascular calcification in renal
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Risk of ischemic heart disease among primary aluminum production workers.
The risk of ischemic heart disease (IHD) has been studied in relation to working conditions encountered in a primary aluminum smelter employing over 6,000 men. During the period 1975-1983, 306 new cases of IHD were identified which were matched with 575 referents. A logistic regression analysis was performed to adjust
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Fluoride & Electrocardiogram Abnormalities
An electrocardiogram (ECG) is a diagnostic test that measures the electrical activity of the heart. An ECG can reveal heart rate, heart rhythym (i.e. steady or irregular), and the strength and timing of the heart’s natural electrical signals. ECGs are described in terms of “waves” (e.g. amplitude and duration). Problems
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Fluoride & Arteriosclerosis
Healthy arteries are flexible and elastic, allowing efficient transfer of blood and nutrients from the heart to the rest of the body. Arteriosclerosis refers to a stiffening of the arteries, including loss of elasticity. This is a slow, progressive disease that may begin early in life from damage to the
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Fluoride & Arterial Calcification
The major change involved with cardiovascular disease is development of atherosclerosis in critical arteries, which is partially characterized by vascular calcification. The level of coronary artery calcification is thought to be the most important indicator of future cardiovascular events. Increased arterial calcifications have frequently been reported in those with skeletal fluorosis
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Fluoride, Blood Pressure and Hypertension
Individuals with blood pressure readings that exceed 140/90 are considered hypertensive. Hypertension can increase the risk of stroke, heart attack, heart failure, aortic aneurysms, and peripheral arterial disease. An association between increased fluoride in ground water and increased prevalence of hypertension has been observed, especially among adult males (Amini et
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Fluoride & Myocardial Damage
Structural damage to the heart resulting from fluoride toxicity has been observed in numerous human and animal studies. The general features of this damage include cloudy swelling, vacuolization or vacuolar degeneration, hemorrhages, interstitial edema, fibrous necrosis, dissolution of nuclei, and thickening of the vessel walls in the heart muscle (Basha
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