Metabolism in hypothermically perfused human kidney carcinoma: utilization and production of amino acids and glucose

Abstract

The metabolism of human kidney carcinoma was studied during hypothermic perfusion. Ten kidneys with carcinomas of different size were perfused in a Gambro perfusion machine for 6 days at +8°C to +10°C. The tumourous kidneys were allocated to one of two groups depending on the relative size of the tumour. Tumours occupying more than 40% of the total kidney volume were designated as ‘large tumours’ and tumours occupying less than 40% as ‘small tumours’. The net glucose uptake was greater during perfusion of kidneys with large tumours than during perfusion of kidneys with small tumours. A lower gluconeogenesis was found in kidneys with large tumours compared to perfusion of kidneys with small tumours and this could explain a large part of the difference in net glucose uptake. The uptake of fatty acids per unit kidney weight was lower during perfusion of kidneys with large tumours. A considerable uptake and release of amino acids were found in both groups. The uptake of proline, aspartate, glycine, and arginine as well as the release of alanine and serine was lower during perfusion of kidneys with large tumours. The nitrogen balance was negative in both groups, with a net release of amino acids to the perfusate. The results suggest a higher glucose uptake, a lower gluconeogenesis, a lower fatty acid uptake and a decreased metabolization of amino acids in the tumour compared to the renal tissue. The model appears promising for studies of human kidney carcinomas at various experimental conditions.

Key Words:

• amino acids
• glucose
• hypothermic perfusion
• kidney neoplasm
• metabolism