Effects of light deprivation on prolactin regulation in the Golden Syrian hamster

Thesis/Dissertation · Wed Jan 01 04:00:00 EST 1986

OSTI ID:6711063

Massa, J S

Pineal-mediated depressions in prolactin cell activity after light deprivation were studied in the male and female Golden Syrian hamster. Prolactin cell activity was determined by measuring radioimmunoassayable prolactin, newly synthesized prolactin, newly synthesized prolactin and prolactin mRNA levels in the pituitary. Serum prolactin was also measured by radioimmunoassay. Use of the recombinant DNA plasmid, pPRL-1, which contains the rat prolactin complimentary DNA sequence, was validated in this dissertation for measuring prolactin mRNA in the hamster. Male Hamsters blinded for 11, 21, or 42 days showed significant and progressively greater declines in prolactin mRNA levels which were completely prevented by pinealectomy. Female hamsters blinded for 28 days, however, showed no such decreases in prolactin cell activity if they continued to display estrous cyclicity. After 12 weeks of blinding, females were acyclic and had dramatically depressed levels of prolactin cell activity. However, pinealectomy did not completely prevent this decline due to blinding unless the females continue to display estrous cyclicity. In ovariectomized females, blinding caused a decline in prolactin cell activity. In a separate study, significant changes in prolactin cell activity during the estrous cycle were seen in untreated normally cycling female hamsters. These changes in prolactin mRNA, prolactin synthesis, and radioimmunoassayable prolactin in the pituitary were measured in the morning, when, consistent with other reports, no differences in serum prolactin were observed.

• Research Organization: Arizona Univ., Tucson (USA)
• OSTI ID: 6711063
• Country of Publication: United States
• Language: English

Related Subjects

550201 -- Biochemistry-- Tracer Techniques
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59 BASIC BIOLOGICAL SCIENCES
62 RADIOLOGY AND NUCLEAR MEDICINE
ANIMALS
BIOCHEMISTRY
BIOLOGICAL EFFECTS
BIOSYNTHESIS
BODY
CELL CONSTITUENTS
CHEMISTRY
DAILY VARIATIONS
DNA
ELECTROMAGNETIC RADIATION
FEMALE GENITALS
GONADOTROPINS
GONADS
HAMSTERS
HORMONES
IMMUNOASSAY
IMMUNOLOGY
ISOTOPE APPLICATIONS
LH
MAMMALS
MEDICINE
MESSENGER-RNA
NUCLEIC ACIDS
ORGANIC COMPOUNDS
ORGANS
OVARIES
PEPTIDE HORMONES
PITUITARY HORMONES
PLASMIDS
RADIATIONS
RADIOASSAY
RADIOIMMUNOASSAY
RADIOIMMUNOLOGY
RECOMBINANT DNA
RNA
RODENTS
SURGERY
SYNTHESIS
TRACER TECHNIQUES
VARIATIONS
VERTEBRATES
VISIBLE RADIATION