D-[3H]galactose incorporation into glycogen in retinal cone cells.
Previous studies have shown that bovine retinas incubated with [3H]galactose incorporated it, unmodified, into large molecules. Light and electron microscope autoradiography showed a significant proportion of the label to be in cone inner segments, and pulse-chase studies showed it was subsequently transported to the synaptic pedicles. In this report, evidence is presented to show that the galactose-labelled macromolecules are resistant to hydrolysis by proteolytic enzymes, testicular hyaluronidase, chondroitinase ABC, beta-glucosidase and beta-glucuronidase, but are readily degraded by alpha-amylase and beta-galactosidase, and to a lesser extent by beta-amylase. Treatment with alpha-amylase also leads to specific removal of radioactivity from cone inner segments and pedicles, as judged by light-microscopic autoradiography. These studies appear to indicate that the cone-specific galactose label is in glycogen or glycogen-like molecules.
Shallal
A
A
Department of Pharmacy, University of Strathclyde, Glasgow, U.K.
McKechnie
N M
NM
Converse
C A
CA
Foulds
W S
WS
D000818:Animals; D001345:Autoradiography; D002417:Cattle; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D004591:Electrophoresis, Polyacrylamide Gel; D005690:Galactose / Q000378:metabolism*; D006003:Glycogen / Q000378:metabolism*; D006868:Hydrolysis; D010786:Photoreceptor Cells / Q000378:metabolism*
D006003:Glycogen; D005690:Galactose