Determination of vitellogenin-like properties in Mya arenaria hemolymph (Saguenay Fjord, Canada): A potential biomarker for endocrine disruption

The level of vitellogenin-like (Vg-like) proteins in the hemolymph of the s oft-shell clam (Mya arenaria) was indirectly determined using an alkali-lab ile phosphate (ALP) measurement assay. Biochemical characterization of hemo lymph from actively reproducing clams showed the presence of Zn, Ca and of substantial amounts of ALP, all of which are indicative of fish serum vitel logenin, reported to be a Zn and Ca containing glycolipophosphoprotein. ALP assays undertaken on different phosphate-containing compounds (phosphate-b uffer saline, diphospholipids and 12,000 x g supernatants of Vg-rich trout ovary homogenates) showed little interference by the first two substrates a nd confirmed the specificity of the ALP assay as an indirect method of dete rmining Vg-like proteins in clam hemolymph. Moreover, clams injected with 1 7 beta-estradiol and two known xenoestrogens (nonylphenol and pentachloroph enol) significantly induced hemolymph ALP levels. Field work revealed signi ficant differences in hemolymph ALP levels from clams collected at specific intertidal stations of the Saguenay Fjord during temporal (May to October) and spatial (June) surveys in 1997, which appear to indicate that (anti-)e strogenic chemicals may be present in the Saguenay Fjord. Our preliminary r esults thus show that this simple and rapid ALP assay holds promise as a bi omarker of estrogen disruption with molluscan shellfish as bioindicators. ( C) 1999 by John Wiley Pc Sons, Inc.