Histopathology of the pituitary gland in neonatal little (lit) mutant mice

Abstract

The pituitary gland in the little (lit) mutant mouse was analyzed with respect to the cytoarchitecture of the pars distalis and the volumetric density of imrnunoreactive growth hormone (GH) cell granules in neonatal litllit and normal C57BL mice. At 8 days postnatally the volume of GH granules/total tissue was significantly less in the IiUlit pars distalis, and the cells were loosely arranged, as compared with the normal pars distalis. In newborn mice a statistically significant difference could not be detected between normal and IiVIit mice with respect to the volumetric density of GH granules; however, differences occurred in the cytoarchitectural organization of the pars distalis. These differences included prominent vascular channels and well-defined cords and clusters of cells in the normal newborn mice, in contrast to indistinct vascular elements and a more diffuse arrangement of cells in livlit.