Androgen-binding levels in a sexually dimorphic muscle of Xenopus laevis

Neil Segil, Lawrence Silverman, Darcy B. Kelley

Research output: Contribution to journalArticle

27 Citations (Scopus)

Abstract

The larynx of adult South African clawed frogs, Xenopus laevis, is larger in males than in females and hypertrophies in adult females and juveniles in response to androgen. Sexual dimorphism and androgen sensitivity suggest that the larynx is a testosterone target tissue. Saturation analysis of androgen (R1881) binding in laryngeal cytosol revealed an approximately threefold quantitative difference between male and female androgen-binding levels (36.4 vs 11.5 fm/mg protein). By contrast, as measured by one-point assay, androgen-binding levels in thigh muscle of either males or females were between 0 and 4 fm/mg protein with no apparent sex difference. Competition studies indicated that dihydrotestosterone was the most effective competitor for R1881 binding activity in the larynx. Saturation analysis showed the binding activity to be saturable and of high affinity (apparent Kd 0.46 nM in the male and 0.38 nM in the female). After 1 month of testosterone treatment, female binding levels averaged 16.6 fm/mg protein with a Kd of 0.49 nM, within the range for normal females. In males castrated for 4 months, binding levels were 52 fm/mg protein. After 1 year of castration, binding levels were 25 fm/mg protein. We conclude that laryngeal muscle is an androgen target tissue with sexually dimorphic levels of binding in adults.

Original languageEnglish (US)
Pages (from-to)95-101
Number of pages7
JournalGeneral and Comparative Endocrinology
Volume66
Issue number1
DOIs
StatePublished - Jan 1 1987
Externally publishedYes

Fingerprint

Xenopus laevis
androgens
Androgens
Muscles
muscles
larynx
Larynx
Metribolone
Proteins
proteins
Sex Characteristics
testosterone
Laryngeal Muscles
Dihydrotestosterone
Castration
castration
thighs
Thigh
hypertrophy
cytosol

All Science Journal Classification (ASJC) codes

  • Animal Science and Zoology
  • Endocrinology

Cite this

@article{95b42e8a5a88441e983c1b33e6bb8656,
title = "Androgen-binding levels in a sexually dimorphic muscle of Xenopus laevis",
abstract = "The larynx of adult South African clawed frogs, Xenopus laevis, is larger in males than in females and hypertrophies in adult females and juveniles in response to androgen. Sexual dimorphism and androgen sensitivity suggest that the larynx is a testosterone target tissue. Saturation analysis of androgen (R1881) binding in laryngeal cytosol revealed an approximately threefold quantitative difference between male and female androgen-binding levels (36.4 vs 11.5 fm/mg protein). By contrast, as measured by one-point assay, androgen-binding levels in thigh muscle of either males or females were between 0 and 4 fm/mg protein with no apparent sex difference. Competition studies indicated that dihydrotestosterone was the most effective competitor for R1881 binding activity in the larynx. Saturation analysis showed the binding activity to be saturable and of high affinity (apparent Kd 0.46 nM in the male and 0.38 nM in the female). After 1 month of testosterone treatment, female binding levels averaged 16.6 fm/mg protein with a Kd of 0.49 nM, within the range for normal females. In males castrated for 4 months, binding levels were 52 fm/mg protein. After 1 year of castration, binding levels were 25 fm/mg protein. We conclude that laryngeal muscle is an androgen target tissue with sexually dimorphic levels of binding in adults.",
author = "Neil Segil and Lawrence Silverman and Kelley, {Darcy B.}",
year = "1987",
month = "1",
day = "1",
doi = "10.1016/0016-6480(87)90354-6",
language = "English (US)",
volume = "66",
pages = "95--101",
journal = "General and Comparative Endocrinology",
issn = "0016-6480",
publisher = "Academic Press Inc.",
number = "1",

}

Androgen-binding levels in a sexually dimorphic muscle of Xenopus laevis. / Segil, Neil; Silverman, Lawrence; Kelley, Darcy B.

In: General and Comparative Endocrinology, Vol. 66, No. 1, 01.01.1987, p. 95-101.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Androgen-binding levels in a sexually dimorphic muscle of Xenopus laevis

AU - Segil, Neil

AU - Silverman, Lawrence

AU - Kelley, Darcy B.

PY - 1987/1/1

Y1 - 1987/1/1

N2 - The larynx of adult South African clawed frogs, Xenopus laevis, is larger in males than in females and hypertrophies in adult females and juveniles in response to androgen. Sexual dimorphism and androgen sensitivity suggest that the larynx is a testosterone target tissue. Saturation analysis of androgen (R1881) binding in laryngeal cytosol revealed an approximately threefold quantitative difference between male and female androgen-binding levels (36.4 vs 11.5 fm/mg protein). By contrast, as measured by one-point assay, androgen-binding levels in thigh muscle of either males or females were between 0 and 4 fm/mg protein with no apparent sex difference. Competition studies indicated that dihydrotestosterone was the most effective competitor for R1881 binding activity in the larynx. Saturation analysis showed the binding activity to be saturable and of high affinity (apparent Kd 0.46 nM in the male and 0.38 nM in the female). After 1 month of testosterone treatment, female binding levels averaged 16.6 fm/mg protein with a Kd of 0.49 nM, within the range for normal females. In males castrated for 4 months, binding levels were 52 fm/mg protein. After 1 year of castration, binding levels were 25 fm/mg protein. We conclude that laryngeal muscle is an androgen target tissue with sexually dimorphic levels of binding in adults.

AB - The larynx of adult South African clawed frogs, Xenopus laevis, is larger in males than in females and hypertrophies in adult females and juveniles in response to androgen. Sexual dimorphism and androgen sensitivity suggest that the larynx is a testosterone target tissue. Saturation analysis of androgen (R1881) binding in laryngeal cytosol revealed an approximately threefold quantitative difference between male and female androgen-binding levels (36.4 vs 11.5 fm/mg protein). By contrast, as measured by one-point assay, androgen-binding levels in thigh muscle of either males or females were between 0 and 4 fm/mg protein with no apparent sex difference. Competition studies indicated that dihydrotestosterone was the most effective competitor for R1881 binding activity in the larynx. Saturation analysis showed the binding activity to be saturable and of high affinity (apparent Kd 0.46 nM in the male and 0.38 nM in the female). After 1 month of testosterone treatment, female binding levels averaged 16.6 fm/mg protein with a Kd of 0.49 nM, within the range for normal females. In males castrated for 4 months, binding levels were 52 fm/mg protein. After 1 year of castration, binding levels were 25 fm/mg protein. We conclude that laryngeal muscle is an androgen target tissue with sexually dimorphic levels of binding in adults.

UR - http://www.scopus.com/inward/record.url?scp=0023317469&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0023317469&partnerID=8YFLogxK

U2 - 10.1016/0016-6480(87)90354-6

DO - 10.1016/0016-6480(87)90354-6

M3 - Article

C2 - 3495467

AN - SCOPUS:0023317469

VL - 66

SP - 95

EP - 101

JO - General and Comparative Endocrinology

JF - General and Comparative Endocrinology

SN - 0016-6480

IS - 1

ER -