Ovariectomized Sprague-Dawley and Long-Evans rats release prolactin differently in response to estrogen
Mature female Sprague-Dawley (SD) and Long-Evans (LE) rats were ovariectomized (OVX), and given a single sc injection of either 25 or 100 ..mu..g polyestradiol phosphate (PEP); seven days later blood samples were withdrawn at two hour intervals from 1100 to 2100 hours to detect the presence of an afternoon surge of prolactin (PRL). Other groups of OVX rats of both strains also treated with PEP were sampled before and at 2, 5, 10 and 30 min after iv administration of 1 ..mu..g synthetic thyrotropin releasing hormone (TRH). Pituitary (AP) and uterine weights were determined following sacrifice one day after TRH treatment. The AP homogenates and plasma samples were assayed for PRL by radioimmunoassay. Rats of both strains had afternoon PRL surges and in both strains the magnitude and/or duration of the surges were enhanced by the higher dose of PEP. However, within each PEP dose LE rats released significantly more PRL during the surge than did SD drats. Rats of both strains also rleased PRL in response to TRH and this response was enhanced in both strains by the higher of the two doses of PEP. These data not only show that strain differences exist in estrogen-induced or mediated PRL release in the rat but also indicate that the differences are not uniform.
- Research Organization:
- Wayne State Univ. School of Medicine, Detroit, MI
- OSTI ID:
- 6472011
- Journal Information:
- Life Sci.; (United States), Vol. 34:5
- Country of Publication:
- United States
- Language:
- English
Similar Records
Concomitant inhibition of pulsatile luteinizing hormone (LH) and stimulation of prolactin release by prostacyclin (PGI/sub 2/) in ovariectomized (OVX) conscious rats
Hepatic metabolism of 7,12-dimethylbenz(a)anthracene in male, female, and ovariectomized Sprague-Dawley rats
Related Subjects
IODINE 125
RADIOIMMUNOASSAY
LTH
BIOCHEMISTRY
HOURLY VARIATIONS
ESTROGENS
OVARIES
PITUITARY GLAND
RATS
SURGERY
UTERUS
ANIMALS
BETA DECAY RADIOISOTOPES
BODY
CHEMISTRY
DAYS LIVING RADIOISOTOPES
ELECTRON CAPTURE RADIOISOTOPES
ENDOCRINE GLANDS
FEMALE GENITALS
GLANDS
GONADOTROPINS
GONADS
HORMONES
INTERMEDIATE MASS NUCLEI
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
MAMMALS
MEDICINE
NUCLEI
ODD-EVEN NUCLEI
ORGANS
PEPTIDE HORMONES
PITUITARY HORMONES
RADIOASSAY
RADIOISOTOPES
RODENTS
STEROID HORMONES
TRACER TECHNIQUES
VARIATIONS
VERTEBRATES
550601* - Medicine- Unsealed Radionuclides in Diagnostics