Role of prolactin in regulating the onset of winter fur growth in mink (Mustela vison): A reconsideration
| Autor: | Jack Rose, Brad Johnston |
|---|---|
| Rok vydání: | 1999 |
| Předmět: |
Androstenediol
endocrine system medicine.medical_specialty medicine.medical_treatment Dehydroepiandrosterone Melatonin biology.animal Internal medicine polycyclic compounds Haloperidol medicine Animals Mink Desoxycorticosterone integumentary system biology Adrenalectomy Dopaminergic Antagonist General Medicine Prolactin Endocrinology Female Animal Science and Zoology Seasons hormones hormone substitutes and hormone antagonists Hair medicine.drug |
| Zdroj: | Journal of Experimental Zoology. 284:437-444 |
| ISSN: | 1097-010X 0022-104X |
| DOI: | 10.1002/(sici)1097-010x(19990901)284:4<437::aid-jez10>3.0.co;2-x |
| Popis: | The objectives of this study were to determine: (1) if the onset of winter hair growth (anagen) in mink could be delayed or inhibited by elevating endogenous PRL concentrations; (2) if bilaterally adrenalectomy (ADX)-induced winter anagen occurs concomitantly with a reduction in serum PRL concentrations, and (3) if exogenous dehydroepiandrosterone (DHEA), an adrenal steroid or Delta(5)-DIOL (a peripherally produced metabolite of DHEA), would delay or inhibit the onset of winter anagen. During early July, while in the resting (telogen) stage of the hair growth cycle, mink were treated with slow release implants containing haloperidol (HAL, a dopaminergic antagonist), melatonin (MEL), deoxycorticosterone (DOC), DHEA and Delta(5)-DIOL. In addition, mink were ADX'd and supplemented with DOC and DHEA. MEL reduced PRL levels to basal levels and induced winter anagen 7 weeks earlier than controls. Surprisingly, HAL initiated winter anagen 7 weeks earlier than controls (P < 0.05), although serum PRL levels were not different between the two groups. Mink that were ADX'd or ADX + DHEA-treated exhibited winter anagen 6 weeks earlier than controls (P < 0.05), but serum PRL concentrations were not different between the three groups. The administration of DHEA or Delta(5)-DIOL to mink with intact adrenals had no effect on the time of onset of winter anagen or serum PRL levels. Our findings suggest that a reduction in circulating PRL levels is not essential for onset of winter anagen in the mink and that the apparent inhibitory effects of the adrenal glands on initiation of winter anagen is not mediated through DHEA or its metabolite Delta(5)-DIOL. J. Exp. Zool. 284:437-444, 1999. |
| Databáze: | OpenAIRE |
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