Radioimmunoassay method for six steroids in human plasma

Brenner, Paul F.; Guerrero, R.; Čekan, Z.; Diczfalusy, E.

doi:10.1016/0039-128x(73)90053-6

Cited by 212 publications

(98 citation statements)

References 15 publications

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“…Since NA in the same concentrations was ineffective towards the LH release of the pituitary tissue incubated in vitro [ 181, it seems that isolated cells are more sensitive to this amine. Supporting our observations, NA did not induce LHRH release from hypothalamic tissue superfused [ 101 or incubated [ isolated from sheep hypothalami [2], and thus it seems unlikely that NA alone can trigger the LHRH discharge of the hypothalamus.…”

Section: In Vitro Cell Suspension 131supporting

confidence: 84%

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Study of the effects of neurotransmitters on the hypothalamus-pituitary-testis function in in vitro cell suspension system

Vermes

Várszegi

Tóth

et al. 1979

Archives of Andrology

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The effects of different neurotransmitters were tested in vitro on a hypothalamic tissue, collagenase-digested isolated anterior pituitary and Leydig cell suspension system by measuring the testosterone production of the Leydig cells. Neurotransmitters were used in concentrations of 0.25, 1.0, 2.5, 5.0, and 10.0 pg/ml incubation medium. Dopamine in doses of 1.0, 2.5, and 5.0 pg/ml increased the hypothalamic tissue-induced pituitary-testis activation, while it had no direct effect on pituitary and Leydig cells. Noradrenaline in the concentration range 2.5-10.0 pg/ml decreased the luteinizing-hormone-releasing-hormone (LHRH) sensitivity of the pituitary cells. 5.0 and 10.0 pglml 5-hydroxytryptamine decreased the testosterone production and the hCG sensitivity of the isolated Leydig cells. Carbamylcholine and pilocarpine had no action on the in vitro system at the different levels studied.

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Section: In Vitro Cell Suspension 131supporting

confidence: 84%

“…At the end of the incubation the suspension were centrifuged and the proteins were denatured. Aliquots of 50-200 p1 were taken for the testosterone radioimmunoassay determination [2]. The sensitivity of the measurement was 15 pglsample, and the within-assay precision of the method was t 10%.…”

Section: Methodsmentioning

confidence: 99%

Study of the effects of neurotransmitters on the hypothalamus-pituitary-testis function in in vitro cell suspension system

Vermes

Várszegi

Tóth

et al. 1979

Archives of Andrology

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“…The petroleum ether extract was then dried under nitrogen and prepared as previously described (Challis, Davies & Ryan, 1973;Brenner et al, 1973). PGF and progesterone standards (10-500 pg of each), plasma samples and tissue extracts were measured by radioimmunoassays.…”

Section: Histochemistrymentioning

confidence: 99%

Effect of abdominal vagotomy of the pregnant rat on LH and progesterone concentrations and fetal resorption

Lawrence¹,

Burden²,

Louis³

1978

Reproduction

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“…The extracts were washed with water, filtered through Na2SO4, and dried. They were chromatographed on Celite 535 columns, according to Brenner et al (18).…”

Section: Methodsmentioning

confidence: 99%

Characterization and measurement of dehydroepiandrosterone sulfate in rat brain.

Corpéchot¹,

Röbel²,

Axelson³

et al. 1981

Proc. Natl. Acad. Sci. U.S.A.

563

324

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Dehydroepiandrosterone (3f3-hydroxy-5-androsten-17-one, I) sulfate (Ia) has been characterized in the anterior and the posterior parts of the brain of adult male rats. Its level (1.58 ± 0.14 and 4.89 ± 1.06 ng/g, mean ± SD, in anterior and posterior brain, respectively) largely exceeded that of I in brain (0.42 ± 0.10 and 0.12 ± 0.03 ng/g in anterior and posterior brain, respectively) and of Ia in plasma (0.26 ± 0.13 ng/ml). Brain Ia level did not seem to depend on adrenal secretion; it was unchanged after administration of corticotropin or dexamethasone for 3 days, and no meaningful change occurred in brain 15 days after adrenalectomy plus orchiectomy, compared with sham-operated controls. In contrast, stress conditions prevailing 2 days after adrenalectomy plus orchiectomy or after the corresponding sham operation resulted in a significantly increased concentration of Ia in the brain. Changes of Ia level in brain occurred irrespective of changes in corresponding plasma samples. It is proposed that Ia formation or accumulation (or both) in the rat brain depends on in situ mechanisms unrelated to the peripheral endocrine gland system. Dehydroepiandrosterone (3,3hydroxy-5-androsten-17-one, I) sulfate (Ia) is below detection limit in the plasma of most adult mammals (1); the exceptions are man and the highest nonhuman primates (1-3). It is a major secretory product ofhuman adrenals (4-7), and its concentration in adult plasma is larger than that of any other steroid. Although Ia is the main precursor of placental estrogens (8-10) and is occasionally converted into active androgens in peripheral tissues (11,12) was added to 2 ml of plasma or <1 g of tissue, and then 5 ml ofacetone/ethanol (1:1) was added. Tissues were homogenized in acetone/ethanol (1:1) with a Teflon/glass homogenizer and sonicated with a Branson Jl sonifier equipped with a minitip at a 100-W setting for 10 sec. The suspensions were kept at 390C overnight and centrifuged at 1000 x g for 10 min. The supernatant was saved, and the pellet was extracted with 4 ml of methanol/chloroform (1:1) with continuous shaking at room temperature for 30 min. The extract was centrifuged, and the two supernatants were combined and taken to dryness. The residue was dissolved in 4 ml of methanol/chloroform (1:1)/10 mM NaCl and deposited on a Sephadex LH-20 column (10 X 445 mm) equilibrated and developed in the same solvent system (15). The first 50 ml to run off contained unconjugated I, Ia was eluted in the next 75 ml. It was completely separated from free I and from I conjugated to fatty acids (16) 4704The publication costs ofthis article were defrayed in part by page charge payment. This article must therefore be hereby marked "advertisement" in accordance with 18 U. S. C. §1734 solely to indicate this fact.

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Radioimmunoassay method for six steroids in human plasma

Cited by 212 publications

References 15 publications

Study of the effects of neurotransmitters on the hypothalamus-pituitary-testis function in in vitro cell suspension system

Study of the effects of neurotransmitters on the hypothalamus-pituitary-testis function in in vitro cell suspension system

Effect of abdominal vagotomy of the pregnant rat on LH and progesterone concentrations and fetal resorption

Characterization and measurement of dehydroepiandrosterone sulfate in rat brain.

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