Potentiating effects of verapamil on cardiovascular teratogenicity of phenobarbital in the chick embryos.
Teratogenic to subteratogenic doses of phenobarbital were administered to young chick embryos together with a calcium-blocking agent, verapamil, at doses where it alone induces no cardiovascular malformations. The cardiovascular teratogenicity of phenobarbital was significantly potentiated by verapamil (5 X 10(-11), 1 X 10(-10) mol). The alteration of calcium movement into the cell and/or depressed cardiac function following impaired calcium transport by verapamil are suggested as modus operandi in the potentiation of phenobarbital-induced cardiovascular malformations.
Nishikawa
T
T
Department of Pathology, Tokyo Women's Medical College, Japan.
Kajita
A
A
Ando
M
M
Takao
A
A
Bruyere
H J
HJ
Gilbert
E F
EF
D000014:Abnormalities, Drug-Induced; D000818:Animals; D001011:Aorta / Q000002:abnormalities*; D002118:Calcium / Q000502:physiology*; D002642:Chick Embryo; D004357:Drug Synergism; D006330:Heart Defects, Congenital / Q000139:chemically induced*; D010634:Phenobarbital / Q000633:toxicity*; D014700:Verapamil / Q000633:toxicity*
D014700:Verapamil; D002118:Calcium; D010634:Phenobarbital