Abstract
Stromal cells and adipocytes were separated after collagenase treatment of adipose tissue obtained from women undergoing elective surgery, and these cells were used to study aromatization of [ 3H]androstenedione in vitro. Aromatization activity was estimated either 1) by determining the incorporation of tritium from [1- 3H]androstenedione into [ 3H]water or else 2) by determining the formation of [ 3H]estrone (E 1) and [ 3H]estradiol (E 2) from [1,2,6,7- 3H]androstenedione. It was established that only 13% of the aromatase activity of adipose tissue resided in the adipocyte fraction, whereas 87% of the aromatase activity was in the stromal/vascular fraction. Subsequent studies of aromatization were conducted utilizing stromal/vascular cells grown to confluence in monolayer culture. In such cells, the formation of [ 3H]E 2 was slower initially but increased with time, and after 48 h of incubation, the amount of [ 3H]E 2 produced exceeded that of [ 3H]E 1. The rate of [ 3H]E 1 formation, as a function of [ 3H]androstenedione concentration, followed Michaeilis-Menten kinetics. The V(max) ranged from 0.8-3.0 pmol mg -1 cell protein 6 h -1 in stromal cells from sc adipose tissue and ranged from 0.16-0.67 pmol mg -1 cell protein 6 h -1 in cells from omental adipose tissue. The apparent K(m) for [ 3H]androstenedione in stromal cells derived from both omental and sc tissue was the same, i.e. about 25 nM. We conclude that the ability of human adipose tissue to form estrogen is not a function primarily of the adipocyte but rather resides principally in the cells of the stroma.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 412-417 |
| Number of pages | 6 |
| Journal | Journal of Clinical Endocrinology and Metabolism |
| Volume | 53 |
| Issue number | 2 |
| State | Published - 1981 |
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ASJC Scopus subject areas
- Biochemistry
- Endocrinology, Diabetes and Metabolism
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Aromatization of androstenedione by human adipose tissue stromal cells in monolayer culture. / Ackerman, G. E.; Smith, M. E.; Mendelson, C. R.; MacDonald, P. C.; Simpson, E. R.
In: Journal of Clinical Endocrinology and Metabolism, Vol. 53, No. 2, 1981, p. 412-417.Research output: Contribution to journal › Article
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TY - JOUR
T1 - Aromatization of androstenedione by human adipose tissue stromal cells in monolayer culture
AU - Ackerman, G. E.
AU - Smith, M. E.
AU - Mendelson, C. R.
AU - MacDonald, P. C.
AU - Simpson, E. R.
PY - 1981
Y1 - 1981
N2 - Stromal cells and adipocytes were separated after collagenase treatment of adipose tissue obtained from women undergoing elective surgery, and these cells were used to study aromatization of [ 3H]androstenedione in vitro. Aromatization activity was estimated either 1) by determining the incorporation of tritium from [1- 3H]androstenedione into [ 3H]water or else 2) by determining the formation of [ 3H]estrone (E 1) and [ 3H]estradiol (E 2) from [1,2,6,7- 3H]androstenedione. It was established that only 13% of the aromatase activity of adipose tissue resided in the adipocyte fraction, whereas 87% of the aromatase activity was in the stromal/vascular fraction. Subsequent studies of aromatization were conducted utilizing stromal/vascular cells grown to confluence in monolayer culture. In such cells, the formation of [ 3H]E 2 was slower initially but increased with time, and after 48 h of incubation, the amount of [ 3H]E 2 produced exceeded that of [ 3H]E 1. The rate of [ 3H]E 1 formation, as a function of [ 3H]androstenedione concentration, followed Michaeilis-Menten kinetics. The V(max) ranged from 0.8-3.0 pmol mg -1 cell protein 6 h -1 in stromal cells from sc adipose tissue and ranged from 0.16-0.67 pmol mg -1 cell protein 6 h -1 in cells from omental adipose tissue. The apparent K(m) for [ 3H]androstenedione in stromal cells derived from both omental and sc tissue was the same, i.e. about 25 nM. We conclude that the ability of human adipose tissue to form estrogen is not a function primarily of the adipocyte but rather resides principally in the cells of the stroma.
AB - Stromal cells and adipocytes were separated after collagenase treatment of adipose tissue obtained from women undergoing elective surgery, and these cells were used to study aromatization of [ 3H]androstenedione in vitro. Aromatization activity was estimated either 1) by determining the incorporation of tritium from [1- 3H]androstenedione into [ 3H]water or else 2) by determining the formation of [ 3H]estrone (E 1) and [ 3H]estradiol (E 2) from [1,2,6,7- 3H]androstenedione. It was established that only 13% of the aromatase activity of adipose tissue resided in the adipocyte fraction, whereas 87% of the aromatase activity was in the stromal/vascular fraction. Subsequent studies of aromatization were conducted utilizing stromal/vascular cells grown to confluence in monolayer culture. In such cells, the formation of [ 3H]E 2 was slower initially but increased with time, and after 48 h of incubation, the amount of [ 3H]E 2 produced exceeded that of [ 3H]E 1. The rate of [ 3H]E 1 formation, as a function of [ 3H]androstenedione concentration, followed Michaeilis-Menten kinetics. The V(max) ranged from 0.8-3.0 pmol mg -1 cell protein 6 h -1 in stromal cells from sc adipose tissue and ranged from 0.16-0.67 pmol mg -1 cell protein 6 h -1 in cells from omental adipose tissue. The apparent K(m) for [ 3H]androstenedione in stromal cells derived from both omental and sc tissue was the same, i.e. about 25 nM. We conclude that the ability of human adipose tissue to form estrogen is not a function primarily of the adipocyte but rather resides principally in the cells of the stroma.
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M3 - Article
VL - 53
SP - 412
EP - 417
JO - Journal of Clinical Endocrinology and Metabolism
JF - Journal of Clinical Endocrinology and Metabolism
SN - 0021-972X
IS - 2
ER -