Depressed prolactin cell activity in long-term blind-pinealectomized female hamsters is due to loss of estrous cyclicity
| Autor: | John S. Massa, David E. Blask |
|---|---|
| Rok vydání: | 1990 |
| Předmět: |
endocrine system
medicine.medical_specialty medicine.drug_class medicine.medical_treatment Radioimmunoassay Hamster Pinealectomy Biology Blindness Pineal Gland General Biochemistry Genetics and Molecular Biology Prolactin cell Estrus Internal medicine Cricetinae medicine Animals RNA Messenger Estrous cycle Sex Characteristics Mesocricetus Body Weight Uterus Organ Size biology.organism_classification Prolactin Endocrinology Estrogen Pituitary Gland Female hormones hormone substitutes and hormone antagonists Hormone |
| Zdroj: | Proceedings of the Society for Experimental Biology and Medicine. Society for Experimental Biology and Medicine (New York, N.Y.). 195(1) |
| ISSN: | 0037-9727 |
| Popis: | Pinealectomy in the female golden Syrian hamster is not always completely effective in preventing the suppressive effects of long-term light deprivation due to blinding on pituitary prolactin (PRL) cell activity. We examined this curious phenomenon by measuring pituitary PRL mRNA levels, PRL synthesis, and radioimmunoassayable PRL, and correlating these changes with the status of estrous cyclicity. As expected, 12 weeks of light deprivation resulted in loss of estrous cyclicity and a greater than 90% decline in all indices of pituitary PRL cell activity, compared with intact cycling controls. Pinealectomy prevented only 40-50% of this decline. However, if noncycling light-deprived pinealectomized animals were excluded, pinealectomy was completely effective, i.e., cycling intact control animals were no different than cycling blind-pinealectomized. We conclude that the inability of pinealectomy to completely prevent the decline in prolactin cell activity seen after blinding is due to the loss of estrous cyclicity in some blind-pinealectomized females, with the attendant loss of the prolactin-stimulating hormone estrogen. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|