Growth Hormone Cells in the Adenohypophysis Compared in Mice with High and Low Incidence of Mammary Tumors by Stereological Morphometry with Electron Microscopy

Abstract

Summary: Growth hormone (GH) cells in the adenohypophysis of adult female mice of the C3H/He strain, with a high incidence of mammary tumors, and of the C57BL/6 strain, with a low incidence of such tumors, were compared by stereological morphometry with electron microscopy. There was no significant difference in the population of GH cells between the two strains of mice. The size of GH cells was significantly larger in the C3H/He mice (P<0.01). In ultrastructural observations by electron microscopy, GH cells in the C3H/He mice contained more secretory granules and better-developed cell organelles than those in the C57BL/6 mice. The body weight was significantly greater in the C3H/He strain than in the C57BL/6 one (P<0.001). These results suggested that GH cells in the C3H/He mice may have higher GH synthetic activity than those in the C57BL/6 strain.