A simple, sensitive, and specific radioreceptor assay for inositol 1,4,5-trisphosphate in biological tissues.
Inositol (1,4,5)P3 (IP3) receptors in rat cerebellar membranes have been used to develop a radioreceptor assay for endogenous IP3. The assay is sensitive, detecting as little as 1 pmole IP3 in a 0.5 ml volume. The receptor is highly selective for the 1,4,5-isomer of IP3 so that assays can employ crude tissue extracts with no purification. Chromatographic analysis and selective enzymatic hydrolysis of IP3 show that in crude tissue extracts only authentic IP3 is detected. A hundred or more samples can be assayed in a day for endogenous IP3.
Bredt
D S
DS
Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205.
Mourey
R J
RJ
Snyder
S H
SH
D000818:Animals; D015220:Calcium Channels; D002462:Cell Membrane / Q000378:metabolism; D002531:Cerebellum / Q000378:metabolism*; D002852:Chromatography, Ion Exchange; D015544:Inositol 1,4,5-Trisphosphate; D053496:Inositol 1,4,5-Trisphosphate Receptors; D007295:Inositol Phosphates / Q000032:analysis* / Q000302:isolation & purification / Q000378:metabolism; D008297:Male; D011869:Radioligand Assay / Q000379:methods; D051381:Rats; D011919:Rats, Inbred Strains; D011956:Receptors, Cell Surface / Q000378:metabolism*; D018160:Receptors, Cytoplasmic and Nuclear; D013403:Sugar Phosphates / Q000032:analysis*; D014316:Tritium
D015220:Calcium Channels; D053496:Inositol 1,4,5-Trisphosphate Receptors; D007295:Inositol Phosphates; D011956:Receptors, Cell Surface; D018160:Receptors, Cytoplasmic and Nuclear; D013403:Sugar Phosphates; D014316:Tritium; D015544:Inositol 1,4,5-Trisphosphate