Effect of 17 β-Estradiol on Phosphoinositide Metabolism and Prolactin Secretion in Anterior Pituitary Cells

Kubota, Toshiro; Kuan, Son-Iu; MacLeod, Robert M.

doi:10.1159/000125255

Cited by 7 publications

(4 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The relationship between estrogens, in particular estradiol, and prolactin have been well known for some time. The direct actions of estrogens stimulating prolactin release are well documented in the literature [ 43 , 44 , 45 ]. In fact, estradiol is an important regulator of prolactin synthesis [ 46 ].…”

Section: Estrogens Prolactin and Aromatasementioning

confidence: 99%

Relation among Aromatase P450 and Tumoral Growth in Human Prolactinomas

Garcı́a-Barrado

Blanco

Iglesias-Osma

et al. 2017

IJMS

View full text Add to dashboard Cite

The pituitary gland is part of hypothalamic-pituitary–gonadal axis, which controls development, reproduction, and aging in humans and animals. In addition, the pituitary gland is regulated mainly by hormones and neurotransmitters released from the hypothalamus and by systemic hormones secreted by target glands. Aromatase P450, the enzyme responsible for the catabolization of aromatizable androgens to estrogens, is expressed in different parts of body, including the pituitary gland. Moreover, aromatase P450 is involved in sexual dimorphism where alteration in the level of aromatase can initiate a number of diseases in both genders. On the other hand, the direct actions of estrogens, mainly estradiol, are well known for stimulating prolactin release. Numerous studies have shown that changes in the levels of estrogens, among other factors, have been implicated in the genesis and development of prolactinoma. The pituitary gland can produce estradiol locally in several types of endocrine cells, and it is possible that aromatase could be responsible for the maintenance of the population of lactotroph cells and the modulation of the action of central or peripheral regulators. Aromatase overexpression due to inappropriate gene regulation has clinical effects such as the pathogenesis of prolactinomas. The present study reports on the synthesis of pituitary aromatase, its regulation by gonadal steroids, and the physiological roles of aromatase on pituitary endocrine cells. The involvement of aromatase in the pathogenesis of pituitary tumors, mainly prolactinomas, through the auto-paracrine production of estradiol is reviewed.

show abstract

Section: Estrogens Prolactin and Aromatasementioning

confidence: 99%

Relation among Aromatase P450 and Tumoral Growth in Human Prolactinomas

Garcı́a-Barrado

Blanco

Iglesias-Osma

et al. 2017

IJMS

View full text Add to dashboard Cite

show abstract

“…2:2:1:0.02). They were separated by chromatograph ic analysis on Dowex AG 1-X8 anion exchange formate resin as described previously [ 18].…”

Section: Measurement Of Inositol Phosphatesmentioning

confidence: 99%

Endothelin-1 as a Local Ovarian Regulator in Porcine Granulosa Cells

Kubota¹,

Kamada²,

Asô³

1994

Horm Res

Self Cite

View full text Add to dashboard Cite

This study was conducted to investigate whether endothelin-1 (ET-1) has direct effects on the functions of porcine granulosa cells harvested from small or medium follicles. Positive ET-1-like immunoreactivity (ET-l-LI) was observed in the cultured porcine granulosa cells, and Northern blot analysis demonstrated the expression of mRNA for prepro-ET-1 in these cells. The binding study showed the presence of a nonselective, single class of binding sites which predominantly included the subtype ET_B. Increased ET-l-LI was detected in human follicular fluid obtained from the patients with stimulated ovarian cycles. ET-1 stimulated basal and follicle-stimulating hormone (FSH)-stimulated secretion of progesterone during short-term incubation (2 h), while it inhibited FSH- and human-chorionic-gonadotropin-stimulated accumulation of progesterone during long-term incubation (48 h) of immature or moderately mature granulosa cells. ET-1 significantly increased DNA synthesis in the cells. These biological actions were induced by ET-1, probably via a cAMP-protein kinase A pathway and intracellular calcium mobilization-protein kinase C pathway. The results suggest that ET-1 exerts autocrine/paracrine effects on porcine granulosa cell functions.

show abstract

“…The frozen monolayers were scraped free in 0-5 ml KC1 (0-2 mol/l)/EGTA (5 mmol/1), pH 7-4, and total inositol phosphates were extracted in an acidified aqueous-organic solvent system (chloroform/methanol/water/hydrochloric acid, 2:2:1:002 by vol.). They were separated by Chromatographie analysis on Dowex AG 1-X8 anion exchange formate resin as described previously (Judd et al 1987;Kubota et al 1989). In the aqueous phase, free [3H]inositol was initially removed with 01 mol HCOOH/1, and the total labelled inositol phosphates fractions were then eluted with HCOOH (01 mol/l)/NH4 COOH (1-0 mol/1).…”

Section: Enzyme-immunoassay Of Prolactinmentioning

confidence: 99%

Protein kinase C activation and calcium mobilization decrease prolactin release from human decidual cells in early pregnancy

Kubota

Kamada²,

Taguchi³

et al. 1993

Journal of Endocrinology

View full text Add to dashboard Cite

The present study was undertaken to investigate the effects of protein kinase C (PKC) activation and calcium mobilization on the release of prolactin from human decidual cells in early pregnancy. Decidua obtained from patients in early pregnancy was enzymatically dispersed and cultured with phorbol myristate acetate (PMA) and calcium ionophore A23187 in a cell culture system. Prolactin in the medium was measured by enzyme-immunoassay. PMA, a PKC activator, dose-dependently attenuated the release of prolactin from cultured decidual cells, while a PKC inhibitor, H7, significantly (P < 0.001) diminished the effect of PMA on prolactin release. PMA had no effect on cell numbers or DNA synthesis in the decidual cells during culture. It did not significantly increase the generation of inositol phosphate in decidual cells prelabelled with myo-[3H]inositol and it had no effect on intracellular calcium concentration ([Ca2+]i). Calcium ionophore A23187, a Ca(2+)-mobilizing agent, also significantly (P < 0.001) attenuated the release of prolactin and potentiated the PMA-induced suppression of prolactin release from decidual cells. These findings suggest that activation of PKC and mobilization of Ca2+ may be involved in regulating prolactin release from human decidual cells. The PMA-induced suppression of prolactin release is not triggered by phosphoinositide hydrolysis nor by the increase in [Ca2+]i in decidual cells.

show abstract

Effect of 17 β-Estradiol on Phosphoinositide Metabolism and Prolactin Secretion in Anterior Pituitary Cells

Cited by 7 publications

References 23 publications

Relation among Aromatase P450 and Tumoral Growth in Human Prolactinomas

Relation among Aromatase P450 and Tumoral Growth in Human Prolactinomas

Endothelin-1 as a Local Ovarian Regulator in Porcine Granulosa Cells

Protein kinase C activation and calcium mobilization decrease prolactin release from human decidual cells in early pregnancy

Contact Info

Product

Resources

About