https://search.dev.ndltd.org/etd/massey/oai:mro.massey.ac.nz:10179/2623
type: CreativeWork
name: The role of the mammary fat pad during mammogenesis : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Animal Science at Massey University, New Zealand
description: Development of the female mammary gland involves the proliferation and morphogenesis of epithelial cells within a matrix of adipose and connective tissue which constitutes the mammary fat pad. The objective of this research was to investigate the mechanisms by which this stromal environment locally regulates postnatal mammogenesis. Initial experiments showed that the mouse mammary fat pad liberates a diffusible activity in vitro which stimulates the growth of mouse mammary epithelial cells and enhances their proliferative response to insulin-like growth factor-I, epidermal growth factor and insulin. This effect was specific to these mitogens, and of a variety of cell lines tested was most pronounced for mouse mammary epithelial cells. Subsequent investigations indicated that these responses were likely induced by unsaturated fatty acids, particularly linoleic acid, from mammary adipocytes. Such responses may be effected by increased intracellular signalling via the actions of protein kinase C. The mitogenic capacity of the mouse mammary fat pad was also evaluated across several physiological states. Mammary fat pad-stimulated proliferation during the estrus cycle was increased at estrus concomitant with a phase of ductal elongation in vivo. In certain medium treatments there was evidence for epithelial upregulation of the mitogenic effect of the mammary fat pad, where intact mammary tissue was more stimulatory than mammary fat pad cleared of endogenous epithelium. Further experiments demonstrated that while the mitogenic effect of the mammary fat pad was unaltered by ovariectomy, ovarian function was required for this effect to be increased by exogenous progesterone. The effect of estrogen was independent of ovarian function but was altered by the local epithelial-stromal interaction, where it increased the mitogenic effect of epithelium-free mammary fat pad and decreased that of intact mammary tissue. Mitogenic stimulation by mammary tissues also declined during vi…
abstract: Development of the female mammary gland involves the proliferation and morphogenesis of epithelial cells within a matrix of adipose and connective tissue which constitutes the mammary fat pad. The objective of this research was to investigate the mechanisms by which this stromal environment locally regulates postnatal mammogenesis. Initial experiments showed that the mouse mammary fat pad liberates a diffusible activity in vitro which stimulates the growth of mouse mammary epithelial cells and enhances their proliferative response to insulin-like growth factor-I, epidermal growth factor and insulin. This effect was specific to these mitogens, and of a variety of cell lines tested was most pronounced for mouse mammary epithelial cells. Subsequent investigations indicated that these responses were likely induced by unsaturated fatty acids, particularly linoleic acid, from mammary adipocytes. Such responses may be effected by increased intracellular signalling via the actions of protein kinase C. The mitogenic capacity of the mouse mammary fat pad was also evaluated across several physiological states. Mammary fat pad-stimulated proliferation during the estrus cycle was increased at estrus concomitant with a phase of ductal elongation in vivo. In certain medium treatments there was evidence for epithelial upregulation of the mitogenic effect of the mammary fat pad, where intact mammary tissue was more stimulatory than mammary fat pad cleared of endogenous epithelium. Further experiments demonstrated that while the mitogenic effect of the mammary fat pad was unaltered by ovariectomy, ovarian function was required for this effect to be increased by exogenous progesterone. The effect of estrogen was independent of ovarian function but was altered by the local epithelial-stromal interaction, where it increased the mitogenic effect of epithelium-free mammary fat pad and decreased that of intact mammary tissue. Mitogenic stimulation by mammary tissues also declined during vi…
author: Hovey, Russell Charles
keywords: Mammary glands, Epithelial cells, Mouse physiology, Ruminant physiology
date published: 1996
date modified: 2026-07-27T20:18:30Z
provider: Massey University
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: Massey University