Alterationen im Testosteronstoffwechsel als Folge einer fehlgeleiteten sexuellen Entwicklung der Ausstattung der Rattenleber mit Enzymen des Steroidhormonstoffwechsels

Schriefers, Herbert; Kley, H K; Rehnitz, Detlev; Lax, E. R.

doi:10.1515/bchm2.1972.353.1.31

Cited by 2 publications

(2 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The authors explain the phenomenon by postulating that estrogen blocks either the neonatal secretion or the action of testosterone. In the same type of male animals the steroid A4-3-keto reduction was also feminized (71). Eimrsson et al recently have reported a feminine pattern in hydroxylation and A4-3-keto reduction of androstenedione and progesterone in liver micro somes of male pseudohermaphrodite rats (22).…”

Section: Sex Differences In Steroid Metabolism In the Rat Liver Are Pmentioning

confidence: 86%

See 1 more Smart Citation

Differentiation of Steroid Metabolism in the Rat and Mechanisms of Neonatal Androgen Action

Denef¹

1973

Enzyme Protein

View full text Add to dashboard Cite

Critical levels of steroid sex hormones during critical phases of development determine sexual differentiation of brain and pituitary. In rats, sex hormone production and metabolism in the gonads, steroid metabolism in the liver, and metabolism of androgen in target tissues of the brain seem to differentiate during similar critical phases. Developmental control of some of the later differentiations manifests ‘imprinting’ during early life by androgen itself. In the liver this neonatal androgen effect is expressed at puberty and seems to require a differentiated pituitary. The high degree of sex-typical diversity in steroid metabolism may be an important mode of control of neural sexual differentiation.

show abstract

Section: Sex Differences In Steroid Metabolism In the Rat Liver Are Pmentioning

confidence: 86%

“…Taken from Denef and De Moor, 1968 (16). manently decreased to female levels in males treated with a high dose of estrogen at birth (28,70,71). The authors explain the phenomenon by postulating that estrogen blocks either the neonatal secretion or the action of testosterone.…”

Section: Sex Differences In Steroid Metabolism In the Rat Liver Are Pmentioning

confidence: 99%

Differentiation of Steroid Metabolism in the Rat and Mechanisms of Neonatal Androgen Action

Denef¹

1973

Enzyme Protein

View full text Add to dashboard Cite

show abstract

Sex Dependency of Steroid Retention in Rat‐Liver Slices Incubated with Testosterone

Ghraf

Lax

Hoff

et al. 1973

European Journal of Biochemistry

Self Cite

View full text Add to dashboard Cite

The hepatic retention of steroids which o c c m during the incubation of [4-14C]testosterone with rat liver slices is demonstrated to be a sex-specific phenomenon. After an incubation time of 30 min, slices from female animals can be shown to have retained significantly more [4-14C]steroid than slices from male animals. The tissue/medium distribution ratio is 13 for the males and 30 for the females.A4-5a-Hydrogenase activity of the liver tissue can be regarded as the driving force for the retention of steroids derived from testosterone turnover. Namely, the steroid retention is positively correlated with the testosterone hydrogenation rate. The A4-hydrogenating activity of the female exceeds that of the male by a factor of 1.73; this is the same factor by which the hepatic retention of the female exceeds that of the male.I n contrast, there is an inverse correlation between the production rate of hydroxylated C,,O,-metabolites and the extent of retention. When compared to the female animal, slices from the male possess a higher hydroxylating activity accompanied by a much lower retention.The majority of metabolites isolated from tissue have a retention which is proportional to their production rate ; however, the proportionality factor varies from metabolite to metabolite. Thus, for each individud metabolite, the slice is able to maintain a specific concentration gradient against the medium. For these metabolites the retention is sex-specific only in so far as their production rate is sex-specific.The retention of testosterone and androstenedione is independent of their production rate. They are found in the incubation medium of both sexes, but only in the tissue of males.The activities of enzymes involved in the metabolism of steroid hormones in the rat liver exhibit distinct sexual differences. As a consequence, the metabolite patterns of hormones, of which those of cortisol [1-31 and testosterone [4--61 are the best studied, are sex-specific.The following investigation exposes a further sex characteristic not previously described. This is the sex-specificity of the processes termed as "uptake, retention and concentration" of steroids in the tissue.It has repeatedly been demonstrated that, in vitro, liver tissue as well as the target organs are able to remove a steroid hormone from the incubation medium, to retain it and concentrate it against a Trivial Name. Testosterone, 17,9-hydroxy-4-tmdrosten%one.Enzymes. A4-5a-Hydrogenase or cortisone-or-reductase or 4,5a-dihydrooortisone : NADPH A4-oxidoreductase (EC 1.3.1.4); steroid hydroxylases or steroid, NADP : oxygenoxidoreductases (EC 1.14.1.6-8).gradient [7-91. With respect to the liver, Bellamy et al. [9], have indicated that ('chemical reaction of the steroid may also be involved in uptake". If this were true, then it follows that the parameters, uptake, retention and concentration, of the female rat liver should be distinct from those of the male.Once sexual differences in these parameters have been established, it should then be possible to determine which o...

show abstract

Alterationen im Testosteronstoffwechsel als Folge einer fehlgeleiteten sexuellen Entwicklung der Ausstattung der Rattenleber mit Enzymen des Steroidhormonstoffwechsels

Cited by 2 publications

References 0 publications

Differentiation of Steroid Metabolism in the Rat and Mechanisms of Neonatal Androgen Action

Differentiation of Steroid Metabolism in the Rat and Mechanisms of Neonatal Androgen Action

Sex Dependency of Steroid Retention in Rat‐Liver Slices Incubated with Testosterone

Contact Info

Product

Resources

About