Development of enzyme-linked immunosorbent assays for isocupressic acid and serum metabolites of isocupressic acid.
The consumption of ponderosa pine (Pinus ponderosa), lodgepole pine (Pinus contorta), common juniper (Juniperus communis), and Monterey cypress (Cupressus macrocarpa) causes abortions in pregnant cattle. Recent studies have identified isocupressic acid (1) as the primary abortificient compound in these plants. In vitro and in vivo studies using rumen and blood have shown isocupressic acid (1) is rapidly metabolized to agathic acid (3), dihydroagathic acid (4), and tetrahydroagathic acid (5). Rapid and sensitive diagnostic techniques are needed to identify poisoned animals, to study toxicokinetics, and to elucidate the mechanism of isocupressic acid-induced abortion in cattle. In this study, four competitive inhibition enzyme-linked immunosorbent assays for isocupressic acid and its sera metabolites were developed using polyclonal antibodies. One assay is specific to 1, whereas the other three assays show cross-reactivity to 3-5 in addition to 1. The assay specific to 1 had a limit of detection of 44.1 pg. The other assays which demonstrated cross-reactivity to the isocupressic acid blood metabolites also had comparably low limits of detection. One assay was used to follow the absorption and elimination profile of isocupressic acid metabolites in both cow serum and urine after oral dosage of a cow with common juniper.
Poisonous Plant Research Laboratory, Agricultural Research Service, U.S. Department of Agriculture, 1150 E. 1400 N., Logan, Utah 84341, USA. stlee@cc.usu.edu
Stephen T
ST
Lee
Dale R
DR
Gardner
Massoud
M
Garrosian
Kip E
KE
Panter
Alessio N
AN
Serrequi
Thomas K
TK
Schoch
Bryan L
BL
Stegelmeier
D000019:Abortifacient Agents / Q000032:analysis / Q000097:blood; D000818:Animals; D002264:Carboxylic Acids / Q000032:analysis* / Q000097:blood* / Q000652:urine; D002417:Cattle; D004224:Diterpenes / Q000032:analysis* / Q000097:blood* / Q000652:urine; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D005260:Female; D018653:Juniperus / Q000737:chemistry; D028223:Pinus / Q000737:chemistry; D024301:Plant Bark / Q000737:chemistry; D011247:Pregnancy; D012680:Sensitivity and Specificity; D013764:Tetrahydronaphthalenes / Q000032:analysis* / Q000097:blood* / Q000652:urine
D000019:Abortifacient Agents; D002264:Carboxylic Acids; D004224:Diterpenes; D013764:Tetrahydronaphthalenes; C110793:isocupressic acid