Epidemiologic relations were evaluated between plasma concentrations of nutrients and cardiovascular diseases. A total of 220 cats were assessed: 144 cats with noninduced acquired heart disease and 76 clinically normal cats. Plasma was assayed for taurine, alpha-tocopherol, selenium, retinol, and total cholesterol and triglycerides concentrations. Cardiovascular disease groups included dilated cardiomyopathy (n = 53), left ventricular hypertrophy (n = 28), hyperthyroidism (n = 11), and uncertain classification (n = 52). In cats with dilated cardiomyopathy, mean plasma taurine concentration was the lowest of that in cats of any group, being only 38% of the value in healthy cats; females had less than half the mean value of males. Tocopherol concentration was 20% lower than normal, and retinol concentration was 40% higher than normal. Total cholesterol concentration was 36% lower than normal. Triglycerides concentration was higher in these cats than in any other group-twice the value recorded in healthy cats and 67% higher than that in hyperthyroid cats. In cats with hypertrophic cardiomyopathy, almost 15% had mean plasma taurine concentration < 30 micromol/L. Retinol concentration was 15% higher, and triglycerides concentration was 54% higher than normal. Approximately 27% of hyperthyroid cats had mildly decreased plasma taurine concentration. Hyperthyroid cats had the lowest tocopherol and cholesterol values; both were at least 30% lower than normal. Retinol concentration was 30% higher than Approximately 14% of cats with uncertain classification had mildly decreased plasma taurine concentration. Plasma retinol and triglycerides concentrations were higher than normal in 25 and 38% of these cats, respectively. Plasma selenium concentration, compared between healthy cats and cats with cardiac disease, was not significantly different. This observation may not be meaningful, however, in light of the limited number of cats in which selenium was assessed.

Although it has been reported that hormones or chemicals, which increse in intracellular cAMP, produced Mg2+ release from the heart, it is not well characterized whether a specific Mg2+ exchanger is involved in cAMP-induced Mg2+ efflux in themammalian hearts In this work, we studied the relationship between the increase in intracellular cAMP and ion transport system on Mg2+ regulation in the perfused rat heart and isolated myocytes. The Mg2+ content in the perfusate and supernatant were measured by atomic absorption spectrophotometer. The addition of membrane permeable cAMP analogue to the perfused hearts and myocytes. cAMP-induced Mg2+ efflux was ingibited by H7, benzamil or imipramine in the perfused hearts and myocytes, but not by EIPA. We confirmed that a significant Mg2+ efflux was induced by an increase in intracellular cAMP in the hearts and myocytes. The cAMP-induced increase of Mg2+ efflux in the hearts may be involved in ion transport system(Na+-Ca2+ and Na+-Mg2+ exchanger)