alexa Effects of estradiol and progesterone on body composition, protein synthesis, and lipoprotein lipase in rats.
Nursing

Nursing

Journal of Patient Care

Author(s): Toth MJ, Poehlman ET, Matthews DE, Tchernof A, MacCoss MJ

Abstract Share this page

Abstract Prior studies suggest that estradiol and progesterone regulate body composition in growing female rats. Because these studies did not consider the confounding effect of changes in food intake, it remains unclear whether ovarian hormones regulate body composition independently of their effects on food intake. We utilized a pair-feeding paradigm to examine the effects of these hormones on body composition. In addition, skeletal muscle protein fractional synthesis rate and adipose tissue lipoprotein lipase activity were measured to examine pathways of substrate deposition into fat and fat-free tissue. Female Sprague-Dawley rats [pubertal: 7-8 wk old; 190 +/- 0.5 (SE) g] were separated into four groups: 1) sham-operated (S; n = 8), 2) ovariectomized plus placebo (OVX; n = 8), 3) ovariectomized plus estradiol (OVX+E; n = 8), and 4) ovariectomized plus progesterone (OVX+P; n = 8). All ovariectomized groups were pair-fed to the S group. Body composition was measured using total body electrical conductivity. The relative increase in fat-free mass was greater (P < 0.01) in the OVX group (31 +/- 2\%) than in the S (17 +/- 2\%), OVX+E (18 +/- 2\%), and OVX+P (22 +/- 2\%) groups. The fractional synthetic rates of gastrocnemius muscle protein paralleled changes in fat-free mass: OVX had a higher (P < 0.05) synthesis rate (21 +/- 3\%/day) than S (12 +/- 2\%/day), OVX+E (11 +/- 2\%/day), and OVX+P (8 +/- 1\%/day) groups. Body fat increased in the S group (31 +/- 7\%; P < 0.01), whereas the OVX groups lost fat (OVX: -10 +/- 7\%; OVX+E: -15 +/- 7\%; OVX+P: -13 +/- 7\%). No differences in lipoprotein lipase were found. Our results suggest that estradiol and progesterone may regulate the growth of fat and fat-free tissues in female rats. Moreover, ovarian hormones may influence skeletal muscle growth through their effects on skeletal muscle protein synthesis.
This article was published in Am J Physiol Endocrinol Metab and referenced in Journal of Patient Care

Relevant Expert PPTs

Relevant Speaker PPTs

Recommended Conferences

Relevant Topics

Peer Reviewed Journals
 
Make the best use of Scientific Research and information from our 700 + peer reviewed, Open Access Journals
International Conferences 2017-18
 
Meet Inspiring Speakers and Experts at our 3000+ Global Annual Meetings

Contact Us

 
© 2008-2017 OMICS International - Open Access Publisher. Best viewed in Mozilla Firefox | Google Chrome | Above IE 7.0 version
adwords