title: Marginal plates in hepatic peroxisomes of Ichthyophis glutinosus (Amphibia: Gymnophiona). A cytochemical study.
abstract: The ultrastructure of hepatic peroxisomes was investigated in Ichthyophis glutinosus (Amphibia: Gymnophiona), employing perfusion fixation and the diaminobenzidine (DAB) technique for the visualization of catalase. The majority of peroxisomes is circular or rod-shaped, although elongated particles occasionally occur. They contain a finely granular matrix, lightly stained after the DAB procedure. Their mean diameter is approximately 0.25 micron. Serial sections reveal that the circular and rod-shaped peroxisomal profiles are cross and oblique sections of highly tortuous, tubular organelles exceeding 2 micron in length. In addition to tubular profiles, elongated, rectangular particles, as well as straight dumbbell-shaped organelles with distinct marginal plates are observed. They range from 900 to 1650 nm in length (mean = 1200 nm). In the flattened, thin central portion of the dumbbell-shaped particle, the peroxisomal membranes form a cisterna enclosing one or two uniformly thick marginal plates, which display a definite substructure with a periodicity of 10 nm. These findings indicate that peroxisomes in the liver of Ichthyophis exhibit a complex organization. It is suggested that the organelles undergo a specific differentiation process, morphologically characterized by the formation of enlarged segments of unusual shape.
mesh_terms: D015100:3,3'-Diaminobenzidine; D000663:Amphibians / Q000033:anatomy & histology*; D000818:Animals; D002374:Catalase / Q000378:metabolism; D003593:Cytoplasm / Q000648:ultrastructure; D008099:Liver / Q000648:ultrastructure; D008830:Microbodies / Q000201:enzymology / Q000648:ultrastructure*
chemical_list: D015100:3,3'-Diaminobenzidine; D002374:Catalase