Antitumor effect of the new rhodium (II) complex: Rh2 (form)2 (O2 CCF3)2 (H2O)2 (form = N,N'-di-p-tolyl formamidinate).
The new rhodium(II) complex Rh2(Form) (O2CCF3)2(H2O)2 (Form = N,N'-di-p-tolyl formamidinate) was evaluated for its toxicity on the rat and for its efficacy against two tumors of this animal: the Yoshida ascites sarcoma and the T8 sarcoma of Guérin. The rhodium(II) formamidinate shows very low toxicity: in fact 150 mg/kg (the highest quantity of drug soluble in 4 ml of dimenthyl sulfoxide) is not toxic for rats. We were unable to establish the lethal dose or the highest nontoxic dose since larger mounts of complex require a dose of dimethyl sulfoxide (DMSO) that is itself toxic and the compound is insoluble in other solvents such as water or Tween. Doses of rhodium(II) formamidinate, varying from 3 to 30 mg/kg, were administered once by i.p., i.v., i.m. and intratumor (i.t.) route from 1 to 7 days after i.p. injection of 10(6) Yoshida ascites sarcoma cells and subcutaneous (s.c.) implantation of approximately 300 mg (corresponding to 2-3 x 10(7) living tumor cells) of T8 sarcoma of Guérin. The compound is active when administered i.p. 24 hours after Yoshida ascites sarcoma at the smallest dose tested (3 mg/Kg), increasing the average life span of 62.3% and allowing the survival of 50% of the rats. It is also active when administered i.p. at the highest dose tested (30 mg/Kg) 7 days after tumor cell challenge, increasing the average life span in 43.8% and allowing survival in 20% of the rats; it is not active after i.v. or i.m administration.(ABSTRACT TRUNCATED AT 250 WORDS)
Fimiani
V
V
Institute of General Pathology, University of Messina, Italy.
Ainis
T
T
Cavallaro
A
A
Piraino
P
P
D000818:Animals; D001201:Ascites / Q000188:drug therapy*; D005260:Female; D005559:Formamides / Q000008:administration & dosage / Q000627:therapeutic use*; D008297:Male; D009942:Organometallic Compounds / Q000008:administration & dosage / Q000627:therapeutic use*; D051381:Rats; D011919:Rats, Inbred Strains; D012513:Sarcoma, Experimental / Q000188:drug therapy*; D014407:Tumor Cells, Cultured
D005559:Formamides; D009942:Organometallic Compounds; C067457:rhodium(II)(N,N'-di-4-tolylformidinate)(trifluoroacetato)