ScienceAsia 24 (1998): 045-056 |doi: 10.2306/scienceasia1513-1874.1998.24.045
SUBPOPULATIONS OF PROLACTIN CELLS DISSOCIATED FROM DIFFERENT PARTS OF RAT ANTERIOR PITUITARY GLAND
ORAWAN RUANGSOMBOONa, GISELE GYSb, BRIGITTE VELKENIERSb AND ELISABETH HOOGHE-PETERSb
ABSTRACT: Two distinct subpopulations of prolactin (Prl) cells with respect to density, staining characteristics and response to secretagogues have been described. After Percoll separation, the low Prl secretors correspond to cells harvested at high density and high Prl secretors are recovered at low density. We previously observed heterogeneity in the Prl gene expression under basal conditions in the intact female pituitary gland: cells located in the periphery of the gland exhibited more Prl mRNA but less immunoreactive Prl protein than cells in the central area. To address the question whether the heterogeneity in the distribution of subpopulations of Prl cells obtained after Percoll gradient separation correspond to that observed in different parts of the rat pituitary, we cut the anterior pituitary of female rats into two parts - the outer peripheral part and the inner central part. Cells from these 2 parts were dissociated, separated by discontinuous Percoll gradient centrifugation and the number of cells containing Prl in each population was determined by the indirect immunoperoxidase technique. The results demonstrate that there is no difference in the number of immunoreactive Prl cells present in cells dissociated from the two parts of the rat anterior pituitary gland when cells harvested from the corresponding density interface are compared.
a Department of Physiology, Faculty of Pharmacy, Mahidol University, 447 SriAyudhya Road Bangkok 10400, Thailand.
b Department of Pharmacology, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel,
Laarbeeklaan 103, B-1090, Brussels, Belgium.
Received February 23, 1998