Abstract: Background – Dilated cardiomyopathy is attributed to taurine deficiency when low blood taurine concentration is found. Nevertheless, skeletal muscle depletes of taurine before blood taurine when diets low in bioavailable sulfur-containing amino acids are given.Hypothesis/Objectives – To assess whether skeletal and cardiac muscle taurine concentrations are correlated, taurine concentrations in semimembranosus muscle and left ventricular free-wall of dog cadavers were determined.Animals – Cadavers of 27 males (21-38 kg) used in student surgery laboratories were studied. They were obtained from animal shelters, preserved by freezing immediately after euthanasia, and dissected after thawing 3 days at 4 °C, then 10 hours at 21-23 °C.Methods – As taurine is not readily degraded in tissues, portions of thawed muscle (0.5 g) were diluted and homogenized in water spiked with internal standard and assayed for taurine content with a validated HPLC-UV phenylisothiocyanate method.Results – Taurine concentrations (median [range]) in skeletal muscle were greater (P< 0.01) than those in cardiac muscle (23 [14-34] vs 17 [11-34] µmol/g). The concentrations were not significantly correlated between the tissues (ρ=-0.22, P=0.26). Cardiac but not skeletal muscle in dogs of the lowest body weight quartile (n=6, < 25 kg) had lower taurine concentrations relative to the other dogs (P< 0.01).Conclusions and clinical importance – The findings add to the little available data on canine cardiac taurine concentrations and indicate taurine depletion in cardiac muscle of dogs may not be well reflected in taurine concentrations in skeletal muscle, which is more accessible for biopsy than myocardium.
