Abstract
Electrophoretic patterns of LDH activity in 4th instar larvae of about 35 mosquito species were compared on polyacrylamide gel plates. When enzyme extracts were prepared from whole・body (W) homogenates, usually only one LDH activity band was detected on the zymogram in about 30 species examined. In the first group of species, an intense LDH band was always detected, but the second group of mosquito larvae showed fluctuation in activities of the enzyme, even within a single species or strain. Furthermore, the third group of mosquito species did not show any detectable activity band, even enzyme concentrations of extracts were highly increased. This difficulty in detecting the LDH band was, however, successfully overcome by removing the larval digestive tract (D) before homogenization. Thus, the use of the W-D enzyme preparation uncovered hidden LDH activity bands, and in some species even an additional band was also visualized by this technique. An inhibitory effect of the D on LDH activity was found to be due to the presence of midgut but not to gastric caeca, hindgut, colon, rectum nor Malpighian tubes.
