Development of pituitary ACTH and GH cells in near term rat fetuses

Abstract

This study describes the development of ACTH and GH cells in 19- and 21-day-old rat fetuses using immunohistochemistry and morphometric measurements. Between days 19 and 21 of pregnancy, the total volume of fetal ACTH cells was unchanged, while their volume density and number per unit of area decreased significantly. ACTH-like immunopositivity in the pars intermedia increased during the examined period. The cell volume, volume density and number of GH cells per unit of area all markedly increased in parallel with fetal development, i.e., from gestational days 19 to 21. GH-like immunopositivity is demonstrated in the pars intermedia of 21-day-old fetuses for the first time.

Keywords

• ACTH cells
• GH cells
• fetuses
• rat