J. H. Anstee

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Apical and basal membrane fractions from Locusta Malpighian tubules were prepared and were characterized by marker enzyme analysis. The apical membranes contained an azide- and orthovanadate-insensitive ATPase activity that was inhibited by bafilomycin A1 (IC50 = 0.44 nM) and NEM (IC50 = 2.15 microM), and thus was characterized as putative V-type ATPase.(More)
Intracellular distributions of Na, K, Mg, Ca, Cl, P, and S were determined in type 1 Malpighian tubule cells of Locusta using X-ray microanalysis. K showed a gradient of increasing concentration from basal to apical surfaces. No other element showed this distribution. Na was below the detection limit. Three types of dark body were present in cytoplasm; one(More)
X-ray microanalysis was used to study elemental distribution in Malpighian tubule cells of Locusta migratoria and how these are affected by the replacement of bathing medium K+ with Rb+ and by inclusion of the transport inhibitors ouabain and n-ethyl maleimide (NEM) in standard (K+-containing) and Rb+-Ringer (K+-free) solutions. Incubation of tubules in(More)
Carbohydrase activity has been demonstrated in homogenates of the alimentary tracts of late instar larvae ofC. maculatus:β-D galactosidase, α-D glucosidase and N-acetylβ-D glucosaminidase activities were comparable and significantly greater than α-D galactosidase,β-D glucosidase and α-D mannosidase. The effects of pH and substrate concentration are(More)
Carbohydrase activity has been demonstrated in homogenates of the alimentary tract ofC. maculatus: β-D galactosidase > α-D glucosidase > α-D galactosidase > β-D glucosidase activity. The effects of pH, temperature and substrate concentration on β-D galactosidase, α-D glucosidase and α-D galactosidase activities are described.
Temperature markedly affected the ouabain-sensitivity of both the Na+−K+-activated ATPase activity and the secretion of fluid by the Malpighian tubules ofLocusta. Varying the K+ concentration in the bathing medium did not affect the ouabain-sensitivity of the fluid secretory process.