THE EFFECTS OF THE BETA-2-AGONIST DRUG CLENBUTEROL ON TAURINE LEVELS IN HEART AND OTHER TISSUES IN THE RAT

The administration of a single subcutaneous dose of clenbuterol to rat s altered the level of taurine in certain tissues. Taurine levels in c ardiac tissue were significantly decreased 3 h after the administratio n of 250 mu g/kg of clenbuterol and remained significantly depressed a t 12 h post-dose only returning to control values by 24 h. The level o f taurine in the liver increased 3 h after clenbuterol administration but was lower than the control value at 24 h post dose. Lung taurine l evels were significantly lower than the control value at 12 hr post do se and remained depressed until 24 h post dose. Clenbuterol caused a s ignificant increase in taurine levels in serum and muscle at 3 and 6 h r postdosing respectively but not at other time points. Serum creatine kinase (CK), activity was slightly but significantly raised at the 12 and 24 h time point. The effects of clenbuterol on tissue taurine con tent were not dose-dependent over the range studied (63-500 mu g/kg). However taurine levels in the lung were significantly reduced at all d oses and in the heart were significantly lower in the treated groups a t all except the lowest dose, 12 h post dosing. Liver taurine levels w ere significantly increased at the highest dose of 500 mu g/kg. The re duction of taurine concentrations in the heart, caused by clenbuterol, is of concern as taurine has been shown to have protective properties in many tissues especially the heart.