Effects of ovariectomy on estrogen uptake capacity, mitotic index and morphology of immunocytochemically-identified gonadotropes

Thesis/Dissertation · Tue Jan 01 04:00:00 EST 1985

OSTI ID:5806130

Smith, P F

The primary objective of these studies was to examine the effects of ovariectomy on the pituitary gonadotrope population in the rat. Several parameters were examined including morphology, mitotic index and ability of individual cells to concentrate estrogen. Adult, female rats which had been ovariectomized 3, 14, or 50 previously, were injected with /sup 3/H-estradiol (i.v.) and killed 1 hour later. Pituitaries were excised and immediately hemisected (mid-sagittal cut). Trunk blood was collected for subsequent radioimmunoassay of serum LH levels to assess the activity of the pituitary gonadotropes. Frozen pituitaries were sectioned and processed for dry-mount autoradiography. Estrogen uptake capacity of gonadotropes increased with time after ovariectomy. This increase was not seen in male rats after castration. Hemi-pituitaries were sectioned (1 ..mu..m) and analyzed for the number of mitotic figures per mm/sup 2/ and dividing cells were characterized as to their hormonal content. Ovariectomy induced an increase in the mitotic index of the pituitary gland. Furthermore, a majority of the mitotic futures seen in the ovariectomized rat were found in cells containing LH-immunoreactivity. Electron microscopic examination of dividing gonadotropes revealed that these cells contained large amounts of vesiculated endoplasmic reticumum typical of post-castration gonadotropes.

• Research Organization: Virginia Univ., Charlottesville (USA)
• OSTI ID: 5806130
• Country of Publication: United States
• Language: English

Related Subjects

550201 -- Biochemistry-- Tracer Techniques
550600* -- Medicine
59 BASIC BIOLOGICAL SCIENCES
62 RADIOLOGY AND NUCLEAR MEDICINE
ANIMALS
AUTORADIOGRAPHY
BIOLOGICAL EFFECTS
BIOLOGICAL MATERIALS
BLOOD
BODY
BODY FLUIDS
CELL DIVISION
ENDOCRINE GLANDS
ESTROGENS
FEMALE GENITALS
GLANDS
GONADS
HORMONES
IMMUNOASSAY
IMMUNOLOGY
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
MAMMALS
MATERIALS
MEDICINE
MITOSIS
ORGANS
OVARIES
PITUITARY GLAND
RADIOASSAY
RADIOIMMUNOASSAY
RADIOIMMUNOLOGY
RATS
RODENTS
STEROID HORMONES
SURGERY
TRACER TECHNIQUES
TRITIUM COMPOUNDS
UPTAKE
VERTEBRATES