Lithium-sensitive production of inositol phosphates during amphibian embryonic mesoderm induction.
Mesoderm induction and body axis determination in frog (Xenopus) embryos are thought to involve growth factor-mediated cell-cell signaling, but the signal transduction pathways are unknown. Li+, which inhibits the polyphosphoinositide (PI) cycle  signal transduction pathway in many cells, also disrupts axis determination and mesoderm induction. Amounts of the PI cycle-derived second messenger, inositol 1,4,5-trisphosphate, increased during mesoderm induction in normal embryos; addition of Li+ inhibited the embryonic inositol monophosphatase and reversed this increase. Embryonic PI cycle activity thus shows characteristics that indicate it may function in mesoderm induction and axis determination.
Maslanski
J A
JA
Department of Biology, Johns Hopkins University, Baltimore, MD 21218.
Leshko
L
L
Busa
W B
WB
D000818:Animals; D002712:Chlorides / Q000494:pharmacology*; D002794:Choline / Q000494:pharmacology; D004625:Embryo, Nonmammalian / Q000502:physiology; D005260:Female; D015544:Inositol 1,4,5-Trisphosphate / Q000378:metabolism; D007295:Inositol Phosphates / Q000378:metabolism*; D007700:Kinetics; D008094:Lithium / Q000494:pharmacology*; D018021:Lithium Chloride; D008648:Mesoderm / Q000187:drug effects / Q000502:physiology*; D015398:Signal Transduction / Q000187:drug effects; D013723:Teratogens / Q000494:pharmacology*; D014981:Xenopus / Q000196:embryology*
D002712:Chlorides; D007295:Inositol Phosphates; D013723:Teratogens; D015544:Inositol 1,4,5-Trisphosphate; D008094:Lithium; D018021:Lithium Chloride; D002794:Choline