by means of the recommended l amino acid mixture was clearly demonstrable using the highly sensitive urine enzyme analyses c f example 2 because the mixture in table 2 is a combination of neutral amino acids exclusively practically no solution imbalances arise for practical clinical reasons the amino acids are dissolved into a 0 45 sodium chloride solution in which chloride is partly replaced by aspartate while controlling ph values ______________________________________amino acid g 1 mm 1______________________________________glycine 11 146l alanine 15 168l serine 15 143l threonine 5 42l valine 10 85l leucine 10 76l isoleucine 4 30l proline 10 87sodium chloride aspartate 4 5 80total 85 857______________________________________ the mixtures in tables 2 and 4 showed a nephroprotective efficacy against nephrotoxic cytostatic example 2 and immunosuppressive pharmaceutical agents example 3 observations revealed that even the side effects of other chemotherapeutic agents themselves not nephrotoxic but mainly renally excreted on other organs e g the haematogenic system were suppressed by the above mentioned l amino acid mixtures the following examples set forth the invention in still greater detail relation of the release of autophagic enzyme activity to regulatory disorder of respiratory mitochondrial function isolated proximal tubular segments its from rat kidneys were exposed to different concentrations of cisplatin were then washed and reincubated cisplatin free.