SKELETAL-MUSCLE METABOLISM IN EXPERIMENTAL HEART-FAILURE

We studied peripheral skeletal muscle metabolism in monocrotaline-trea ted rats. Two distinct groups emerged: a percentage of the animals dev eloped ventricular hypertrophy, with no signs of heart failure (compen sated group), whilst others, besides ventricular hypertrophy, develope d the syndrome of congestive heart failure (CFH group). Oxidative meta bolism and redox cellular state were expressed in terms of creatine ph osphate, purine (ATP, ADP and AMP) and pyridine (NAD and NADH) nucleot ides tissue content, Skeletal muscles with different metabolism were s tudied: (a) Soleus (oxidative), (b) extensor digitorum longus (glycoly tic) and tibialis anterior (oxidative and glycolytic). The results sho wed that in CFH animals a decreased high-energy phosphates content occ urs in the soleus and extensor digitorum longus, but not in the tibial is anterior, In the soleus, ATP declined from 20.31 +/- 2.5 of control group to 9.55 +/- 0.6l mu mol/g dry wt, while in the extensor digitor um longus ATP declined from 30.92 +/- 2.68 to 22.7 +/- 1.54 mu mol/g d ry wt. In both these muscles, a shift of NAD/NADH couple towards oxida tion was also observed (from 26.58 +/- 3.34 to 6.95 +/- 0.97 and from 18.88 +/- 3.43 to 10.57 +/- 1.61, respectively), These alterations wer e more evident in the aerobic soleus muscle. On the contrary, no major changes occurred in skeletal muscle metabolism of compensated animals . The results show that: (1) a decrease in muscle high-energy phosphat es occurs in CFH; (2) this is accompanied by a decrease of NAD/NADH co uple suggesting an impairment in oxygen utilization or availability. ( C) 1996 Academic Press Limited