Hypophyseal–adrenal Activity in Combined Human Foetal Tissue Cultures

Stark, E.; Gyévai, A; Szalay, Katalin Sz.; Ács, Zs.

doi:10.1139/y65-001

Cited by 46 publications

(9 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Thompson, Vincent, Jensen, Price & Schapiro (1959) established that both adult and foetal human pituitary could produce growth hormone (GH), thyroid-stimulating hormone (TSH), adrenocorticotrophic hormone (ACTH) and gonadotrophins in tissue culture. Subsequent investiga¬ tions demonstrated that late foetal pituitaries can synthesize prolactin and main¬ tain adrenal steroidogenesis (Brauman, Brauman & Pasteéis, 1964;Stark, Gyevai, Szalay & Acs, 1965). Rice, Ponthier & Sternberg (1968) found that luteinizing hormone (LH) was secreted by the 6-month foetal pituitary.…”

Section: Introductionmentioning

confidence: 99%

The Secretion of Immuno-Reactive Luteinizing Hormone and Follicle-Stimulating Hormone by the Human Foetal Pituitary in Organ Culture

Groom¹,

Groom²,

Cooke³

et al. 1971

Journal of Endocrinology

View full text Add to dashboard Cite

Foetal human pituitaries of 8\p=n-\18weeks gestational age were maintained in tissue culture for up to 6 days. No morphological change was observed in the tissue during this period. Radioactive glucosamine was continuously incorporated into medium protein and the levels of luteinizing hormone (LH), follicle-stimulating hormone (FSH) and growth hormone in the medium increased with the duration of the culture. Theophylline stimulated the release of both LH and FSH consistently over the 6 days, and the total amount of each hormone released over this period was significantly greater than that in unstimulated control cultures. Cyclic adenosine 3' , 5' \ x=req-\ monophosphate stimulated FSH release to some extent but had no significant effect on LH release.

show abstract

Section: Introductionmentioning

confidence: 99%

The Secretion of Immuno-Reactive Luteinizing Hormone and Follicle-Stimulating Hormone by the Human Foetal Pituitary in Organ Culture

Groom¹,

Groom²,

Cooke³

et al. 1971

Journal of Endocrinology

View full text Add to dashboard Cite

show abstract

“…The steroid hormones are believed to activate the metabolising sys tem whereas the polypeptide hormones make use of a reserve system linked to the cyclic AMP system. The further effects of the polypeptide hormones, however, are quite distinct from those produced immediately by cyclic AMP and many long term effects of these hormones are observed, such as the observations that maximal stimulation of steroidogenesis in adrenal cortex tissues occurs three days after administration of ACTH [82], The physicochemical analysis of the mechanism of hormone action may be the most significant in determining the specificity of the hormone. The inter action with specific receptors leads to biochemical changes in the tissue that may be characterised.…”

Section: Resultsmentioning

confidence: 99%

Mechanism of Hormonal Action

Snart¹

1970

Horm Res Paediatr

View full text Add to dashboard Cite

A review of evidence supporting a general mechanism of action of steroid hormones has been made by comparing the action of aldosterone in stimulating sodium transport across toadbladder, with corticosterone stimulation of gluconeogenic enzymes in rat liver and oestradiol binding in rat uterus. Related aspects of the mechanism of action of neurohypophyseal hormones have been considered in terms of the ‘pore’ and cyclic AMP theories.

show abstract

“…It has been observed previously that an increase in steroid secretion in response to ACTH by fetal adrenal tissue maintained in culture may be delayed 2-3 days (62,63,65). However, in those experiments, HFA tissue was maintained in culture in the absence of ACTH for 6-9 days before treatment with ACTH.…”

Section: Organ Culture As a Model For Evaluating Cholesterol Metamentioning

confidence: 92%

“…Adrenal tissue obtained from human abortuses has been found to remain viable in culture for periods up to 28 days (62). Most investigators have evaluated the effects of ACTH on adrenal tissue explants after 6-8 days of culture (63)(64)(65).…”

Section: Organ Culture As a Model For Evaluating Cholesterol Metamentioning

confidence: 99%

Lipoprotein Utilization and Cholesterol Synthesis by the Human Fetal Adrenal Gland*

Carr¹,

Simpson²

1981

Endocrine Reviews

145

View full text Add to dashboard Cite

A model proposed for regulation of steroidogenesis, lipoprotein utilization and cholesterol metabolism in HFA tissue is presented in Fig 17. We envision that the role of ACTH and cAMP in steroidogenesis and cholesterol metabolism is as follows. ACTH binds to specific receptors on the surface of the cells of the HFA gland and as a consequence, adenylate cyclase is activated, leading to increased formation of cAMP. cAMP causes activation of protein kinase that leads, presumably, to phosphorylation of specific proteins. This leads to the initiation of reactions that give rise to increased activity of key enzymes and levels of proteins involved in adrenal cholesterol metabolism. Presumably, the action of ACTH causes an increase in the activity of cholesterol side chain cleavage, the rate-limiting step in the conversion of cholesterol to steroid hormones. We suggest that once the mitochondrial cholesterol side-chain cleavage system is fully activated by ACTH, the supply of cholesterol to the mitochondria becomes rate-limiting for steroidogenesis. To meet this demand for cholesterol, a further action of ACTH results in an increase in the number of LDL receptors. LDL binds to specific receptors on the cell surface that are localized in coated pits. LDL is internalized by a process of adsorptive endocytosis and the internalized vesicles fuse with lysosomes and the protein component of LDL is hydrolyzed by lysosomal proteolytic enzymes to amino acids. The cholesteryl esters of LDL also are hydrolyzed to give rise to fatty acids and cholesterol. The liberated cholesterol is available for utilization in the biosynthesis of steroid hormones and other cellular processes. In addition, ACTH stimulates the activity of HMG CoA reductase and, thus, the rate of de novo cholesterol biosynthesis. In this way sufficient cholesterol is obtained to provide for precursor cholesterol to maintain the high rate of steroid synthesis by the HFA. HDL is not utilized as a source of cholesterol by the HFA. Because of the rapid rate of utilization of LDL by the HFA, fetal plasma levels of LDL are low and the activity of the HFA is a primary determinant of these levels. Thus, in the case of anencephaly, in which the activity of the adrenal is very low, plasma levels of LDL are 2--3 times higher than in normal fetuses, whereas plasma HDL levels are similar. In addition, in the normal neonate plasma LDL levels rise rapidly after birth, and this event is coincident with the involution of the fetal zone of the adrenal. The fetal liver is likely to be the major source ultimately of the LDL-cholesterol utilized by the HFA. Consequently, factors that regulate cholesterol and lipoprotein synthesis in the fetal liver may, in turn, affect the steroidogenic activity of the HFA through regulation of the supply of cholesterol precursor. Thus, if trophic factors for the HFA other than ACTH exist, an important site of their action might be the fetal liver, rather than a direct action to influence the rate of synthesis of steroids by the fetal adrenal.

show abstract

Hypophyseal–adrenal Activity in Combined Human Foetal Tissue Cultures

Cited by 46 publications

References 4 publications

The Secretion of Immuno-Reactive Luteinizing Hormone and Follicle-Stimulating Hormone by the Human Foetal Pituitary in Organ Culture

The Secretion of Immuno-Reactive Luteinizing Hormone and Follicle-Stimulating Hormone by the Human Foetal Pituitary in Organ Culture

Mechanism of Hormonal Action

Lipoprotein Utilization and Cholesterol Synthesis by the Human Fetal Adrenal Gland*

Contact Info

Product

Resources

About