Effects of aging and obesity on aromatase activity of human adipose cells

W. H. Cleland, C. R. Mendelson, E. R. Simpson

Research output: Contribution to journalArticle

148 Citations (Scopus)

Abstract

Adipose tissue is the principal site of estrogen formation in postmenopausal women; with advancing age as well as with increased body weight, there is an increase in the fractional conversion of circulating androstenedione to estrone. We have studied the effects of aging as well as body weight on aromatase activity of adipose tissue specimens taken from 50 women of various ages and weights. Since aromatase activity of adipose tissue is detectable primarily in stromal cells, these cells were incubated with [1-3H]androstenedione (150 nM), and estrogen formation was assayed by measuring the incorporation of tritium into [3H]water. The aromatization rate, when normalized on the basis of equal numbers of cells, increased with increasing age (P<0.03; r = 0.43). In contrast, when expressed as a function of body weight, no change in aromatase activity of adipose stromal cells were found. Aromatization of androstenedione by cells from young women who had undergone oophorectomy was not increased compared with that of cells from young women with normal ovarian function, indicating that the onset of menopause per se and the accompanying increase in circulating gonadotropin levels were not causative factors in the increased aromatase activity of adipose stromal cells. We conclude, therefore, that increased estrone production associated with aging may result from an increase in the specific activity of the aromatase enzyme in adipose stromal cells and is not affected by changes in gonadotropin concentrations associated with menopause. On the other hand, the increase in estrogen formation as a function of obesity is probaby due to increased numbers of adipose cells, rather than to an increase in the specific activity of aromatase in those cells.

Original languageEnglish (US)
Pages (from-to)174-177
Number of pages4
JournalJournal of Clinical Endocrinology and Metabolism
Volume60
Issue number1
StatePublished - 1985

Fingerprint

Aromatase
Human Activities
Obesity
Aging of materials
Stromal Cells
Androstenedione
Adipose Tissue
Aromatization
Estrogens
Estrone
Tissue
Menopause
Gonadotropins
Cell Count
Body Weight
Body Weight Changes
Tritium
Ovariectomy
Weights and Measures
Water

ASJC Scopus subject areas

  • Biochemistry
  • Endocrinology, Diabetes and Metabolism

Cite this

Effects of aging and obesity on aromatase activity of human adipose cells. / Cleland, W. H.; Mendelson, C. R.; Simpson, E. R.

In: Journal of Clinical Endocrinology and Metabolism, Vol. 60, No. 1, 1985, p. 174-177.

Research output: Contribution to journalArticle

@article{cc0d52bb86f047debb80b52265f75acd,
title = "Effects of aging and obesity on aromatase activity of human adipose cells",
abstract = "Adipose tissue is the principal site of estrogen formation in postmenopausal women; with advancing age as well as with increased body weight, there is an increase in the fractional conversion of circulating androstenedione to estrone. We have studied the effects of aging as well as body weight on aromatase activity of adipose tissue specimens taken from 50 women of various ages and weights. Since aromatase activity of adipose tissue is detectable primarily in stromal cells, these cells were incubated with [1-3H]androstenedione (150 nM), and estrogen formation was assayed by measuring the incorporation of tritium into [3H]water. The aromatization rate, when normalized on the basis of equal numbers of cells, increased with increasing age (P<0.03; r = 0.43). In contrast, when expressed as a function of body weight, no change in aromatase activity of adipose stromal cells were found. Aromatization of androstenedione by cells from young women who had undergone oophorectomy was not increased compared with that of cells from young women with normal ovarian function, indicating that the onset of menopause per se and the accompanying increase in circulating gonadotropin levels were not causative factors in the increased aromatase activity of adipose stromal cells. We conclude, therefore, that increased estrone production associated with aging may result from an increase in the specific activity of the aromatase enzyme in adipose stromal cells and is not affected by changes in gonadotropin concentrations associated with menopause. On the other hand, the increase in estrogen formation as a function of obesity is probaby due to increased numbers of adipose cells, rather than to an increase in the specific activity of aromatase in those cells.",
author = "Cleland, {W. H.} and Mendelson, {C. R.} and Simpson, {E. R.}",
year = "1985",
language = "English (US)",
volume = "60",
pages = "174--177",
journal = "Journal of Clinical Endocrinology and Metabolism",
issn = "0021-972X",
publisher = "The Endocrine Society",
number = "1",

}

TY - JOUR

T1 - Effects of aging and obesity on aromatase activity of human adipose cells

AU - Cleland, W. H.

AU - Mendelson, C. R.

AU - Simpson, E. R.

PY - 1985

Y1 - 1985

N2 - Adipose tissue is the principal site of estrogen formation in postmenopausal women; with advancing age as well as with increased body weight, there is an increase in the fractional conversion of circulating androstenedione to estrone. We have studied the effects of aging as well as body weight on aromatase activity of adipose tissue specimens taken from 50 women of various ages and weights. Since aromatase activity of adipose tissue is detectable primarily in stromal cells, these cells were incubated with [1-3H]androstenedione (150 nM), and estrogen formation was assayed by measuring the incorporation of tritium into [3H]water. The aromatization rate, when normalized on the basis of equal numbers of cells, increased with increasing age (P<0.03; r = 0.43). In contrast, when expressed as a function of body weight, no change in aromatase activity of adipose stromal cells were found. Aromatization of androstenedione by cells from young women who had undergone oophorectomy was not increased compared with that of cells from young women with normal ovarian function, indicating that the onset of menopause per se and the accompanying increase in circulating gonadotropin levels were not causative factors in the increased aromatase activity of adipose stromal cells. We conclude, therefore, that increased estrone production associated with aging may result from an increase in the specific activity of the aromatase enzyme in adipose stromal cells and is not affected by changes in gonadotropin concentrations associated with menopause. On the other hand, the increase in estrogen formation as a function of obesity is probaby due to increased numbers of adipose cells, rather than to an increase in the specific activity of aromatase in those cells.

AB - Adipose tissue is the principal site of estrogen formation in postmenopausal women; with advancing age as well as with increased body weight, there is an increase in the fractional conversion of circulating androstenedione to estrone. We have studied the effects of aging as well as body weight on aromatase activity of adipose tissue specimens taken from 50 women of various ages and weights. Since aromatase activity of adipose tissue is detectable primarily in stromal cells, these cells were incubated with [1-3H]androstenedione (150 nM), and estrogen formation was assayed by measuring the incorporation of tritium into [3H]water. The aromatization rate, when normalized on the basis of equal numbers of cells, increased with increasing age (P<0.03; r = 0.43). In contrast, when expressed as a function of body weight, no change in aromatase activity of adipose stromal cells were found. Aromatization of androstenedione by cells from young women who had undergone oophorectomy was not increased compared with that of cells from young women with normal ovarian function, indicating that the onset of menopause per se and the accompanying increase in circulating gonadotropin levels were not causative factors in the increased aromatase activity of adipose stromal cells. We conclude, therefore, that increased estrone production associated with aging may result from an increase in the specific activity of the aromatase enzyme in adipose stromal cells and is not affected by changes in gonadotropin concentrations associated with menopause. On the other hand, the increase in estrogen formation as a function of obesity is probaby due to increased numbers of adipose cells, rather than to an increase in the specific activity of aromatase in those cells.

UR - http://www.scopus.com/inward/record.url?scp=0021930760&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0021930760&partnerID=8YFLogxK

M3 - Article

C2 - 3964790

AN - SCOPUS:0021930760

VL - 60

SP - 174

EP - 177

JO - Journal of Clinical Endocrinology and Metabolism

JF - Journal of Clinical Endocrinology and Metabolism

SN - 0021-972X

IS - 1

ER -