Bull. Environ. Contam. Toxicol. (2000) 64:287-293
© 2000 Springer-Verlag New York Inc.
Diazinon Induced Changes in the Serum Proteins of Large
Mouth Bass, Micropterus salmoides
G. Pan, H. Dutta
Department of Biological Sciences, Kent State University, Kent, OH 44242, USA
Received: 14 April 1999/Accepted: 13 December 1999
Diazinon [O,O-Diethyl O-(2-isopropyl-6-methyl-4-pyrimidinyl) phosphorothioate] is
a broad spectrum organophosphorus pesticide extensively used all over the world to
control flies, cockroaches, lice on sheep, insect pests of ornamental plants and food
crops (almonds, corn, apples and tobacco), nematodes, soil insects in lawns and
croplands (Smith 1993). Smith (1993) reported that the annual acreage planted with
diazinon treated seeds in the U.S. is estimated to be 1,150,000.
Toxicants, including diazinon, can enter the bloodstream through the gills or the
gastrointestinal tract (Doving 1991). Thus, evaluation of fish blood provides valuable
information concerning the physiological response of fish to changes in the external
environment, including the presence of toxicants such as diazinon. (Van Vuren et al.,
1994). Electrophoretic determination of the serum proteins of dying fish may provide
legal evidence in suspected pollution cases (Brooke 1964). Thus, this study employs
the electrophoresis and densitometer readings of SDS-PAGE gel to analyze the effect
of diazinon on the serum proteins of largemouth bass (Micropterus salmoides).
MATERIALS AND METHODS
The detailed methods of collection, acclimation and exposure of fish are explained in
Pan and Dutta, 1998. Prior to blood sampling, five fish from each group were
anesthetized with tricaine methane sulfonate (MS-222) using 100 mg/L tap water.
Blood samples of 0.3 to 0.6 mL were obtained by direct cardiac puncture through the
base of the heart. The heart was exposed by a midline incision and the pericardium
was partially removed. This method is preferred over the caudal vessel method since
it yields a larger blood sample. The sampling of blood was performed in May 1996
to avoid seasonal variations of serum proteins. The collected blood was allowed to
clot completely for one hour at room temperature. These blood samples were
centrifuged for 15 minutes at 3600 RPM to separate the serum from the cells. The
supernatant was pipetted from the centrifuge tube and transferred to a microcentrifuge
tube. The samples were stored for two weeks at -20° C before the electrophoretic
study was conducted.
Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) with a
vertical, discontinuous buffer Mini-PROTEAN II Cell/PowerPac 300 System was
Correspondence to: H. Dutta