K. Spanelborowski et al., ISOLATION OF GRANULOSAL-LIKE CELLS FROM THE BOVINE SECRETORY CORPUS-LUTEUM AND THEIR CHARACTERIZATION IN LONG-TERM CULTURE, The Anatomical record, 239(3), 1994, pp. 269-279
Background: The isolation of cells termed type 5 from the bovine corpu
s luteum was recently reported. Since these cells were reminiscent of
immature granulosa cells, their morphological and functional relations
hip requires further investigation in view of the novel concept of cor
pus luteum growth. It suggests that putative stem cells of unknown ori
gin supply the pool of small luteal cells. Methods: Bovine corpora lut
ea were mechanically dispersed, cell suspensions separated over a Perc
oll(R) density gradient, and type 5 cells purified by colony transfer.
Granulosa cells were harvested from small-sized antral follicles. Obs
ervations were carried out at the light and electron microscopical lev
el. 3 beta-Hydroxy-steroid-dehydrogenase was localized histochemically
in addition to intracellular lipid droplets stained with nile red. Im
munolocalization was used to study Factor VIII antigen presence, the a
rchitecture of the cytoskeleton, as well as the occurrence of neuronal
cell adhesion molecules, and of neuronal cadherin-like molecules. The
uptake of acetylated low density lipoprotein was examined. As for pro
gesterone concentration, cells were seeded at low density on day zero.
Cell numbers and progesterone levels of supernatants were determined
on day 10 in culture. Results and Conclusions: Type 5 cells behaved mo
rphologically Like immature granulosa cells, yet the total cell number
and the progesterone concentration differed for type 5 cells compared
to granulosa cells. The addition of LH had no influence on the proges
terone concentration as seen for either type 5 cells or for granulosa
cells. It is concluded that type 5 cells, which were originally mistak
en for microvascular endothelial cells, display similarities with imma
ture granulosa cells. Type 5 cells may play a role in renewal of lutea
l cells. (C) 1994 Wiley-Liss, Inc.