Size distribution of luteal cells from pregnant and non-pregnant marmoset monkeys and a comparison of the morphology of marmoset luteal cells with those from the human corpus luteum.
The size distribution of marmoset luteal cells was determined on Days 6, 14 and 20 after ovulation in non-pregnant cycles and in early pregnancy. Image analysis was used to estimate the cell diameter of dispersed cells prepared from the marmoset corpus luteum (CL). Steroidogenic cells showed a size distribution consistent with one population of cells. There was a significant increase in mean cell diameter (P less than 0.05) from Day 6 to Day 14 in pregnant and non-pregnant animals with no further increase on Day 20. Micrographs of marmoset luteal tissue showed cells of greater than 10 micron containing the organelles typical of steroid-producing cells, and smaller non-steroidogenic cells surrounding the steroid-producing cells. On the basis of microscopy, there were no areas within the CL where cell composition was noticeably different. In contrast, micrographs of human luteal tissue showed two types of steroidogenic cell; most cells were similar to those in the marmoset CL but a smaller population of smaller cells could be distinguished around the periphery and along vascular septa. It is likely that these smaller and larger types of steroidogenic cells are of theca and granulosa cell origin respectively, the two cell populations differing in the degree of electron density and amount of rough endoplasmic reticulum. A distinguishing feature between marmoset and human luteal cells was the shape of the mitochondrian which were considerably rounder in marmoset luteal cells. The origin of steroidogenic cells in the marmoset CL is unclear, although in marmosets and man the luteal cell types display morphological characteristics distinct from the large and small luteal cells described for CL of the domestic ungulates.
Webley
G E
GE
MRC/AFRC Comparative Physiology Group, Institute of Zoology, London, UK.
Richardson
M C
MC
Smith
C A
CA
Masson
G M
GM
Hearn
J P
JP
D000818:Animals; D002144:Callithrix / Q000033:anatomy & histology*; D003338:Corpus Luteum / Q000166:cytology* / Q000648:ultrastructure; D004721:Endoplasmic Reticulum / Q000648:ultrastructure; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008928:Mitochondria / Q000648:ultrastructure; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D011270:Pregnancy, Animal / Q000502:physiology*