ISSN:
1573-4919
Keywords:
prolactin receptor
;
mouse mammary gland
;
in situ localization
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
Notes:
Abstract The receptors for prolactin (PRLR) are expressed in many tissues including the mammary gland, a classical target tissue for prolactin (PRL), but the cellular localization of expression of the PRLR gene in mammary gland has not yet been identified. PRL is known to up regulate its own receptor. We therefore employed the pituitary isografted mouse as a model to distinguish the cells expressing PRLR since PRL blood levels are known to be constitutively elevated in these animals. Mammary glands of virgin or pituitary isografted mice were analyzed by northern blot orin situ hybridization with a digoxygenin-labeled cRNA probe. Northern analysis revealed the expression of 1.3 kb and 2.5 kb forms of PRLR corroborating the results of various laboratories studying other tissues. PRLR was barely detectable byin situ hybridization in non-isografted mice. Two weeks after pituitary isografting, however, PRLR expression was substantially increased in the epithelial cells of mammary ducts and alveoli. No signal was ever detected in the mammary stromal compartment of either virgin or pituitary-isografted mice. The localization of PRL-responsive cells to the parenchyma of the mammary gland suggests that epithelial cells are the mediators of PRL action and that the transcriptional regulation of PRLR expression by PRL is direct in the epithelial cell.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00926923
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