Related Experiment Videos
Sexual difference in LH-cells of the neonatal rats as revealed by immunocytochemistry
Insights
Pituitary luteinizing hormone (LH)-cells in neonatal rats increase post-birth. Sexual differences emerge after 4 days, with females showing a greater increase in LH-cell number than males.
Area of Science:
- Reproductive biology
- Endocrinology
- Developmental biology
Background:
- Pituitary gland development is crucial for reproductive functions.
- Understanding the ontogeny of hormone-producing cells provides insights into sexual differentiation.
Purpose of the Study:
- To investigate the localization and number of pituitary luteinizing hormone (LH)-cells in neonatal male and female rats.
- To determine the onset of sexual dimorphism in LH-cell populations during early postnatal development.
Main Methods:
- Immunoenzymological procedures using anti-hCG serum.
- Quantitative analysis of LH-cell distribution and number in rat pituitaries from birth to 12 days of age.
Main Results:
- LH-cell numbers increased with age in both sexes.
- Equal numbers of LH-cells were observed in males and females until postnatal day 4.
- After day 4, females exhibited a significantly higher rate of LH-cell proliferation compared to males.
- LH-cells were predominantly located ventrally, with regional variations in anterior and posterior pituitary.
- Cellular dispersion towards dorsal areas, especially in females post-day 4, was noted.
Conclusions:
- Sexual differences in pituitary LH-cell populations become apparent after the 4th day of postnatal life in rats.
- The observed differences suggest a sexually dimorphic development of the pituitary gland during early life.
Abstract:
Localization and number of pituitary LH-cells were studied in neonatal male and female rats (from the birth to 12th day) applying anti-HCG serum in immunoenzymological procedures. The cells increased in number with developing age after birth. The cells in males and females were equal in number until 4 days of age, wheres thereafter the increase of the cell number in females exceeded that in males. After birth, the cells are mainly concentrated ventrally, being ventro-lateral in the anterior region but converging into the medial-ventral area in the posterior part of the gland. Some dispersion in a dorsal direction is also noted in the latter region. At birth the cells begin to appear in the dorsal area in the anterior portion, as well as in the posterior portion, particularly in the area close to the intermediate lobe and in the zone adjacent ot the residual lumen. This was particularly evident in females after 4 days of age. Thus it is concluded that in rats the sexual differences in the pituitary become apparent after the 4th day of postnatal life.