EFFECTS OF MAINTENANCE TEMPERATURE ON THE AMINO ACID CONTENT OF BIOMPHALARIA GLABRATA SNAILS AS DETERMINED BY HIGH PERFORMANCE THIN-LAYER CHROMATOGRAPHY-DENSITOMETRY

Abstract

High performance thin-layer chromatography-densitometry (HPTLC-Dens) was used to determine the free-pool amino acid content of whole bodies of sexually immature Biomphalaria glabrata snails maintained at 15, 24, or 31°C. Amino acids were extracted from whole snail bodies in 70:30 ethanol-water and separated on either silica gel or cellulose stationary phases with 2-butanol-pyridine-glacial acetic acid-deionized water (39:34:10:26) or 2-butanol-pyridine-25% ammonia-deionized water (39:34:10:26). Amino acid zones were visualized by postchromatographic derivatization with ninhydrin and quantified by visible mode slit-scanning densitometry at 610 nm. Comigration of bands with amino acid stock solutions confirmed the presence of alanine, arginine, asparagine, aspartate, glutamate, glutamine, glycine, lysine, threonine, and valine in all samples. Multiple t-test comparisons showed a significant increase in valine in snails maintained at 15°C compared to those at 31°C at 3 weeks post-treatment (P < 0.015). This finding could suggest that there are inherent variations in the metabolism of snails cultured at different temperatures.

Keywords:

• amino acids
• Biomphalaria glabrata
• densitometry
• high performance thin layer chromatography
• HPTLC
• temperature effects
• valine

ACKNOWLEDGMENTS

We thank Dr. Fred A. Lewis for supplying the B. glabrata snails used in this study through NIH-NIAD contract N01-AI-AI-55270.

Notes

^a Value significantly increased compared to samples from snails maintained at 31°C (Student's t-test, P < 0.015).