Amino acid uptake in skeletal muscle of rats bearing the Yoshida AH-130 ascites hepatoma.
Rats bearing the Yoshida AH-130 ascites hepatoma show decreased activity of neutral amino acid transport in skeletal muscle measured in vivo as the tissue accumulation of the analogue alpha-amino [1-14C]isobutyrate (AIB). The decreased accumulation of AIB observed is not merely a consequence of the hypoinsulinaemia present in these animals (as a result of tumour burden) since in vitro experiments carried out using incubations of isolated soleus muscles also showed a decreased uptake of neutral amino acids. In these preparations the addition of insulin results in similar increases in uptake both in the pair-fed controls and the tumour-bearing animals, thus suggesting similar insulin sensitivities. The decrease in amino acid uptake in soleus muscle is associated with a decrease in the activity of system A, while systems L and ASC show no particular changes as a result of the tumour growth. The kinetic characterisation of system A in the Yoshida-bearing rats shows a decrease in Vmax together with a decrease in KM in relation with the pair-fed animals.
D000596:Amino Acids / Q000378:metabolism*; D000621:Aminoisobutyric Acids / Q000493:pharmacokinetics*; D000818:Animals; D001201:Ascites; D001692:Biological Transport; D002100:Cachexia / Q000209:etiology / Q000378:metabolism; D005260:Female; D007328:Insulin / Q000097:blood; D008114:Liver Neoplasms, Experimental / Q000150:complications / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000378:metabolism* / Q000473:pathology; D009929:Organ Size; D051381:Rats; D017208:Rats, Wistar
D000596:Amino Acids; D000621:Aminoisobutyric Acids; D007328:Insulin; C100049:2-aminoisobutyric acid