Reduced Tissue Androgen Receptors in the Congenitally Obese Male Zucker Rat

Bannister, P.; Whitaker, E. M.

doi:10.1677/joe.0.107r013

Cited by 7 publications

(3 citation statements)

References 11 publications

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“…Reduced concentrations of oestradiol receptors have been found in the uteri of obese rats (Saiduddin & Zassenhaus, 1979). Reduced concen¬ trations of androgen receptors in the prostate and liver of obese rats have also been reported (Bannister & Whitaker, 1985). The response of peripheral target tissues to gonadal steroids may, therefore, be abnor¬ mal in obese Zucker rats.…”

Section: Introductionmentioning

confidence: 94%

Circulating reproductive hormones and hypothalamic oestradiol and progestin receptors in infertile Zucker rats

Whitaker¹,

Robinson²

1989

Journal of Endocrinology

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Plasma concentrations of LH, FSH, prolactin and progesterone were measured during the oestrous cycle in obese (fa/fa) and non obese (Fa/?) Zucker rats. In obese rats the mid-afternoon surge of LH during prooestrus was reduced compared with that in non-obese rats (P less than 0.05), and the maximum concentrations of FSH and prolactin declined more slowly during oestrus. Progesterone concentrations were higher during most of the oestrous cycle in obese rats. Oestradiol and progestin receptors were measured in the hypothalamus of female Zucker rats. Lower concentrations of oestradiol receptors were found in the preoptic area of obese rats (P less than 0.05). Concentrations of oestradiol receptors in the medial basal hypothalamus were also lower in obese rats, though the difference was not statistically significant. Concentrations of progestin receptors were similar in both phenotypes in the preoptic area and media basal hypothalamus. It seems likely that the abnormalities in reproductive hormones and oestradiol receptors contribute to the infertility of obese female Zucker rats. The underlying mechanism has still to be determined.

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Section: Introductionmentioning

confidence: 94%

Circulating reproductive hormones and hypothalamic oestradiol and progestin receptors in infertile Zucker rats

Whitaker¹,

Robinson²

1989

Journal of Endocrinology

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“…The presence of reduced AR concentration in diseased liver is in broad agreement with the data from Nagasue et al (lo), who reported on hepatocellar carcinoma and the surrounding parenchyma. This is not a disease-specific process for it has been reported in experimental alcoholic liver disease (1 8), chronic active hepatitis and congenital steatosis (14). The significance of this reduction may be two-fold.…”

Section: Discussionmentioning

confidence: 91%

Androgen receptor concentrations in needle biopsy specimens of human liver

Bannister

Meystre

Losowsky

1988

Liver

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The liver is a steroid-responsive organ and contains high levels of androgen receptors (AR). The present study investigated cytosolic AR concentrations in diseased human liver obtained by needle biopsy. Insufficient tissue was available for full Scatchard analysis. Previous studies have shown the binding affinity of the liver AR to be sufficiently constant to allow the use of a single saturating dose analysis, using 'Hmibolerone as the active ligand, for the estimation of binding sites. Thirteen samples were studied and compared to normal liver. AR was identified in all samples and the level negatively correlated to the degree of liver damage. A role for AR in hepatocellular carcinoma has been postulated and anti-androgens used in treatment. This study shows AR can be measured in needle-biopsy specimens and, if hepatocellular carcinoma is proven to be hormone sensitive, then this technique may help in the assessment of such tumours.

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“…An alternative explanation is that AR levels are reduced in a non-specific manner by tissue damage and then become expressed during the process of carcinogenesis. This concept is supported by the fact that liver AR are also reduced in hepatic steatosis of either congenital (Bannister & Whitaker, 1985) or alcohol induced aetiology (Eagon et al, 1985), or in simple chronic active hepatitis without cirrhosis (Nagasue et al, 1985 oral contraceptive-associated hepatic adenoma. No studies have been performed on ER levels during the pre-malignant phase of tumour production but in a single case report ER levels were increased in focal nodular hyperplasia (Porter et al, 1983b).…”

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confidence: 93%