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Evidence for luteal cell hyperplasia during pregnancy
L T Goldsmith1, A N Hirshfield
1Department of Obstetrics and Gynecology, UMDNJ-New Jersey Medical School, Newark 07103.
Biology of Reproduction
|March 1, 1991
Summary
During rat pregnancy, luteal cell hyperplasia, or cell division, contributes to corpus luteum growth. This study provides evidence that new luteal cells are generated, increasing parenchymal cell numbers.
Area of Science:
- Reproductive biology
- Cell biology
- Endocrinology
Background:
- Corpus luteum growth during pregnancy is primarily attributed to luteal cell hypertrophy.
- The role of luteal cell hyperplasia (cell division) in corpus luteum growth is debated, with a prevailing belief that cell division does not occur in vivo.
Purpose of the Study:
- To investigate whether luteal cell hyperplasia occurs during rat pregnancy.
- To determine if new luteal cells are generated, contributing to the increase in corpus luteum size.
Main Methods:
- Timed-pregnant rats were implanted with osmotic minipumps delivering 3H-thymidine continuously.
- Ovaries were collected on Day 13 and Day 18 of pregnancy for autoradiography.
- Autoradiography was used to identify and quantify labeled cells with luteal cell morphology.
Main Results:
- Labeled cells with morphological characteristics of luteal cells were observed in the ovaries.
- The labeling index was 6.0% for cells exposed from Day 6-13 and 1.2% for cells exposed from Day 11-18 of pregnancy.
- These findings demonstrate an increase in parenchymal cell number within the corpus luteum during pregnancy.
Conclusions:
- The study provides evidence supporting luteal cell hyperplasia during rat pregnancy.
- Regardless of the precise origin of the labeled cells, their presence indicates an increase in the number of parenchymal cells in the corpus luteum.
- This challenges the long-held belief that luteal cell division does not occur in vivo during pregnancy.