Platinum drugs: combined anti-lymphoproliferative and nephrotoxicity assay in rats.

A 4-day drug schedule was used to explore the efficacy and simultaneous toxicity of cisplatin and 30 other platinum (II) amines given IP to PVG x Lew F1 hybrid rats at cumulative doses of 10-300 mumol/kg. Toxic effects monitored were stomach enlargement, kidney hypertrophy with tubular necrosis and proteinuria, evident visceral mucin, and lymphoid involution (thymus, spleen). Immunosuppressive effects were monitored as inhibition of the lymph node hypertrophy induced by grafting PVG spleen cells into each paw of F1 hybrids. No significant activity/toxicity was observed with 'platinum-(pyrimidine) blues'. N-alkyl derivatives of cisplatin were less active/toxic and some had no immunosuppressant effect, though they are reported as effective antitumour agents (in mice). mu-Hydroxobridged aminoplatinum (II) dimers were highly toxic, effective immunosuppressants and their toxicity profiles were distinct from the dihalo or diaquo diaminoplatinum species. 1,2-Diaminocyclohexane platinum derivatives showed a wide range of potency, all being much less nephrotoxic than cisplatin.