Pinocytotic vesicles and microfilaments observed by scanning electron microscopy.
Pinocytotic vesicles and microfilaments were clearly demonstrated by high resolution scanning electron microscopy. Mesothelial cells covering the newt liver were excised and treated with a hypotonic phosphate buffer solution (150 mOsm) for 1-2 minutes. After fixation with 2.5% glutaraldehyde, some specimens were placed in 20% glycerin solution for 24 hours. After being postfixed with 1% osmic solution, they were treated with 2% tannic acid and 1% osmic solution for conductive staining. After dehydration in a graded series of ethanol, the deeper layers of the mesothelium were exposed by scratching or rubbing the specimen in absolute ethanol. When some part of the surface cell membrane was turned over, many pinocytotic vesicles could be successfully seen attached to the cytoplasmic side of the membrane. The vesicles were also observed on the basal cell membrane. In the deeper layer of the cell exposed by scratching or rubbing the specimen, intracellular fibers presumably microfilaments were spread in the whole cell body forming "cytoskeleton".
D000818:Animals; D002462:Cell Membrane / Q000648:ultrastructure; D003599:Cytoskeleton / Q000648:ultrastructure*; D008099:Liver / Q000502:physiology / Q000648:ultrastructure*; D008855:Microscopy, Electron, Scanning / Q000379:methods; D010873:Pinocytosis; D012455:Salamandridae