Effect of cis-diamminedichloroplatinum (II) on rat thymocyte membrane potential.
The effect of cis-diamminedichloroplatinum (II) (cisDDP) on rat thymocytes has been investigated. Changes of anisotropy constant and depolarization of the cell membrane have been determined. The effect of cisDDP on the anisotropy constant has been observed on treated animal thymocytes but not on treated isolated cell membranes. CisDDP inhibits KCl-induced depolarization in isolated rat thymocytes. This inhibiting effect is still present at a concentration as low as 5 microM and it is dose-dependent with a 9.6 microM ED50. CisDDP also boosts the inhibition of the polarization caused by 10 microM tetrodotoxin (TTX) and 10 microM doxorubicin (DOXO). The replacement of Na+ by choline and the inactivation of Ca2+ by EGTA, in the incubation medium, reduces the inhibiting effect of cisDDP on the KCl-induced depolarization. These results suggest that cisDDP induced alterations could be due to the interference of cisDDP with the activity of the ionic channels pertaining to Na+ and Ca2+. This interference is stronger for Na+ channels.
Florio
S
S
Dept. of Structures, Functions and Biological Technologies, University Federico Il, Napoli, Italy.
Pagnini
G
G
Pagnini
U
U
Crispino
A
A
D000818:Animals; D000903:Antibiotics, Antineoplastic / Q000494:pharmacology; D000970:Antineoplastic Agents / Q000494:pharmacology*; D000992:Antitoxins / Q000494:pharmacology; D002945:Cisplatin / Q000494:pharmacology*; D004317:Doxorubicin / Q000494:pharmacology; D005260:Female; D066298:In Vitro Techniques; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects*; D051381:Rats; D017208:Rats, Wistar; D013779:Tetrodotoxin / Q000494:pharmacology; D013950:Thymus Gland / Q000187:drug effects* / Q000502:physiology*
D000903:Antibiotics, Antineoplastic; D000970:Antineoplastic Agents; D000992:Antitoxins; D013779:Tetrodotoxin; D004317:Doxorubicin; D002945:Cisplatin