The Effects of Progesterone on Body Weight and Composition in the Rat

Abstract

SUMMARY The effects of progesterone administration on the weight and composition of the body have been studied in rats. Female rats injected with 5 mg. progesterone/day initially gained weight at an average rate of 2 g./day, compared with 0·4 g./day for controls. When treatment was continued for a month or more their weight stabilized at 40–50 g. above the control level. The bodies of the progesterone-treated rats contained increased amounts of water, fat and solids other than fat. These effects were smoothly related to the dose of progesterone. In terms of percentage composition, fat increased at the expense of the other two constituents. The composition of the fat-free solids did not change, but the proportion of water in the fat-free body increased. About a tenth of the gain of live weight was accounted for by an increase in the contents of the alimentary tract. The composition of the rest was equivalent, typically, to 43% lean tissue, 26% water additional to that in the lean tissue, and 31% fat. Male rats treated with progesterone showed no changes other than a small gain of water. It seems likely that in females progesterone reproduces the changes in body composition which occur in pregnancy. The gain of lean tissue seems to reflect increased growth it, and the accumulation of fat, may both be consequences of the production of a positive energy balance.

The Relationship Between Plasma Progesterone Concentration and Conception in Post-Partum Dairy Cows Maintained on Two Levels of Nutrition

“…The effects of nutrition may be further confounded by the possible effect of progesterone on body weight changes (Gilbert & Gillman, 1956;Dewar, 1957;Hervey & Hervey, 1967 …”

An Autoradiographic Study of the Early Effects of 7,12-Dimethylbenz(a)anthracene and Progesterone on DNA Synthesis in Rat Mammary Epithelial Cells and Subsequent Tumour Development

“…Whether progesterone also acts directly on rat mammary tissue in this way is unknown. Available evidence suggests that progesterone may stimulate breast tissue indirectly via the hypothalamus and pituitary gland, the effect being due to increased secretion of prolactin (LTH) and possibly also growth hormone (STH) (Huggins, Mainzer and Briziarelli, 1958;Rothchild, 1960;Kim, 1965;Clementi and De Virgiliis, 1967;Hervey and Hervey, 1967;Sar and Meites, 1968;Welsch et al, 1968). Both LTH and STH have been shown to stimulate markedly mammary growth in rats, even in the absence of the pituitary gland and ovaries (Furth and Clifton, 1957;Talwalker and Meites, 1961;Dao and Gawlak, 1963;Talwalker, Meites and Mizuno, 1964;Sinha and Tucker, 1968;Takizawa, Furth and Furth, 1970).…”

Effects of diet and progesterone on the cellularity of parametrial adipose tissue in mice

“…As in obesity induced by a high-fat diet, no overeating was observed, but excessive fat development could be related to a decrease of spontaneous activity. Progesterone promotes body weight gain (Bourdel and Jacquot, 1965) by increasing the adipose mass (Hervey and Hervey, 1967 ;Krotkiewski and Bj6rntorp, 1976). The administration of progesterone seems to reproduce the physiological situation of pregnancy, weight gain being supplied by 30 to 40 p. 100 of fat (Hervey and Hervey, 1967).…”

“…Progesterone promotes body weight gain (Bourdel and Jacquot, 1965) by increasing the adipose mass (Hervey and Hervey, 1967 ;Krotkiewski and Bj6rntorp, 1976). The administration of progesterone seems to reproduce the physiological situation of pregnancy, weight gain being supplied by 30 to 40 p. 100 of fat (Hervey and Hervey, 1967). Birke and Archer (1975) and Guttman et al (1975) found variations in locomotor activity and behavioral response in an open field during the murine estrous cycle.…”

“…It is known that progesterone promotes the development of adipose mass (Hervey and Hervey, 1967). In experimental obesities in laboratory animals, increased adipose mass results from different modifications of adipose tissue cellularity.…”