title: Inclusion bodies in pinealocytes of the cotton rat (Sigmodon hispidus). An ultrastructural study and X-ray microanalysis.
abstract: Pinealocytes of the cotton rat (Sigmodon hispidus) often contain large (2-6 micron diameter) intracytoplasmic inclusions, the function of which is not known. These inclusions may represent nucleolus-like bodies, mineral deposits, secretory products or viral inclusions. In this study these inclusions were classified as type A, B or C inclusions based on the amount of electron-dense material interspersed within the finely granular material comprising the bulk of these inclusions. Each type of inclusion was analyzed by X-ray microanalysis and enzymatic proteinaceous digestion. X-ray microanalysis of these inclusions differed both quantitatively and semiquantitatively from that of human or gerbil pineal concretions, the latter two of which are extracellular deposits. Pronase, a proteolytic enzyme, digested the electron-dense material only after longer times of tissue exposure to this enzyme in contrast to the easily digested, finely granular matrix-like material of these inclusions. Such intrapinealocytic inclusions have only been observed in the cotton rat. Their functional significance remains unknown.
mesh_terms: D000818:Animals; D003411:Arvicolinae / Q000033:anatomy & histology*; D004577:Electron Probe Microanalysis; D005260:Female; D002479:Inclusion Bodies / Q000187:drug effects / Q000648:ultrastructure*; D008297:Male; D010870:Pineal Gland / Q000187:drug effects / Q000648:ultrastructure*; D011402:Pronase / Q000494:pharmacology
chemical_list: D011402:Pronase