INFLUENCE OF INSULIN ON MAINTENANCE AND SECRETORY STIMULATION OF MOUSE MAMMARY TISSUES BY HORMONES IN ORGAN-CULTURE<sup>1</sup>

Rivera, Evelyn M.; Bern, Howard A.

doi:10.1210/endo-69-2-340

Cited by 95 publications

(29 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The observations of Hardy (26), Lasfargues (27,28), and Elias (29), on the maintenance and differentiation of mouse mammary tissue cultivated in vitro, laid the basis for extensive further study of this system and definition of the hormonal requirements for cell differentiation and milk protein production (30)(31)(32)(33)(34)(35).…”

Section: Discussionmentioning

confidence: 99%

Human Prolactin: Measurement in Plasma by In Vitro Bioassay

Kleinberg¹,

Frantz²

1971

J. Clin. Invest.

103

View full text Add to dashboard Cite

A B S T R A C T Prolactin has been measured in unex-tracted human plasma by a sensitive and specific in vitro bioassay. Secretory activity of breast tissue fragments from mid-pregnant mice, incubated in organ culture with human plasma, serves as the histologic end point.Sensitivity is 5 ng/ml (0.14 mU/ml) or somewhat better for ovine prolactin, and approximately 0.42 mU/ml for prolactin activity of human plasma at the dilutions used in the assay. Human growth hormone as it circulates in blood, like the material extracted from pituitary glands, is strongly lactogenic. Antisera to human growth hormone are capable of completely neutralizing the prolactin effect of large amounts (600 ng/ml) of human growth hormone added to the system. Plasma prolactin activity is less than 0.42 mU/ml in normal men and women. Of 26 patients with nonpuerperal galactorrhea, 14 had elevated prolactin activities ranging from 0.42 to 3.5 mU/ml. Growth hormone levels by radioimmunoassay were far too low, in general, to account for the observed prolactin activity. All of 14 nursing mothers, 1-30 days post partum, had elevated prolactin activity with a mean of 2.29 and a total range of 0.56-4.5 mU/mi.Growth hormone was in the low normal range in all of these subjects. Seven patients on psychoactive drugs of the phenothiazine series similarly had elevated prolactin activity with low growth hormone. Antiserum to human growth hormone, when preincubated with plasma samples from each of these three groups of subjects, produced no significant inhibition of prolactin activity. In two acromegalic patients with markedly elevated growth hormone levels, antiserum to growth hormone produced complete inhibition of prolactin activity in one and partial inhibition in the other. These studies indicate that human growth hormone and human prolactin This work was presented in part at

show abstract

Section: Discussionmentioning

confidence: 99%

Human Prolactin: Measurement in Plasma by In Vitro Bioassay

Kleinberg¹,

Frantz²

1971

J. Clin. Invest.

103

View full text Add to dashboard Cite

show abstract

“…Among the hormones, I + Prl + cortisol, needed for production of casein in mammary explants in culture, insulin, a metabolic hormone, is required for maintenance of the epithelium in the culture medium (24,25). Recent results obtained in our laboratory showed that adrenalectomy-induced 85-92% reduction of casein mRNA activity of the lactating mammary gland of the mouse is preventable by cortisol injections.…”

Section: Methodsmentioning

confidence: 99%

Hormone-inducible casein messenger RNA in a serum-free organ culture of whole mammary gland

Terry

Banerjee

Lui

1977

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

View full text Add to dashboard Cite

The whole second thoracic mammary gland of estradiol-17fi + progesterone primed 3-to 4-week-old BALB/c femalemice was induced to pregnancy-like lobulo-ilveolar morphogenesis after 6-day cultivation in a serum-free culture medium containing a "growth promoting" hormone mixture, insulin + prolactin + growth hormone (somatotropin) + estra- Mammary cells responding to appropriate hormones in a serum-free, chemically defined medium thus provide a favorable system for studying the multiple hormone interactions regulating production of the milk protein. The specific protein synthesis associated with most endocrine-dependent systems is believed to be regulated by hormonal modification of mRNA population in the target tissue (5, 6). Testing the biological properties of hormone-inducible mRNA requires a direct assay system. Previously we have reported that casein mRNA of the lactating mammary gland of the mouse is faithfully translated in a heterologous cell-free protein synthesis system, derived from ascites tumor cell ribosomes, rabbit reticulocyte factors, and tRNA (7). This report presents the results of our studies on cell-free translation of casein mRNA induced by lactogenic hormones in a serum-free organ culture of the whole mammary gland obtained from an immature female mouse. MATERIALS AND METHODSOrgan Culture. As a prerequisite for the organ culture procedure (3) 3-to 4-week-old BALB/c female mice were primed for 9 days by daily injections (subcutaneous) of 1 ,ug of estradiol-17fl (E) and 1 mg of progesterone (P) in 0.9% saline suspension. The entire second thoracic mammary gland was excised under sterile conditions and cultivated in Falcon plastic culture dishes (60 X 15 mm) containing chemically defined Waymouth's (8) medium (MB752/1 supplemented with Lglutamine (350,gg/ml), penicilin (35 ,g/ml), and different combinations of hormones. The incubation was carried out at 370 in an atmosphere of 95% 02 + 5% CO2 according to the standard procedure (9). The method of organ culture of the whole mammary gland of the mouse has been described in detail (4, 10). For morphological studies the glands were fixed in a mixture of acetic acid and ethanol (1:3) and for biochemical analysis glands were frozen in liquid nitrogen and stored at -80°.Indirect Radioimmunoassay. The mammary tissue was homogenized in a buffer containing 10 mM NaPO4 + 15 mM NaCl (pH = 7.5). The homogenate was centrifuged at 100,000 X g for 1 hr at 4°. Different concentrations of protein (11) in the resulting Sloo supernate were assayed for presence of casein by an indirect radioimmunoassay using 125I-labeled mouse milk casein and casein antiserum, as previously described (12).RNA Extraction. Frozen mammary tissue was pulverized in a mortar and pestle cooled by liquid nitrogen. The tissue powder was then homogenized in a power-driven glass tissue grinder containing six volumes of buffer A (13) and the RNA was extracted by phenol/chloroform, followed by high-salt wash as described by Palmiter (13). According to Palmiter, for translational assays ...

show abstract

“…This provided an in vitro model for studying molecular responses of the mammary cells to prolactin and glucocorticoid action in a chemically defined medium containing insulin, which is needed for viability of the mammary parenchyma in vitro (9). Subsequently, it was observed that prolactin stimulates casein synthesis as well as transcriptional activity in the explants that were preincubated with cortisol (10,11).…”

mentioning

confidence: 99%

Absolute requirement of glucocorticoid for expression of the casein gene in the presence of prolactin.

Ganguly¹,

Ganguly²,

Mehta³

et al. 1980

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

View full text Add to dashboard Cite

Second thoracic mammary glands of immature BALB/c female mice were stimulated to pregnancy-like lobuloalveolar (LA) development after 6 days of incubation in a corticosteroid-free step I culture medium containing insulin, prolactin, estradiol, progesterone, and growth hormone. A low basal level (0.0009%) of casein mRNA (mRN4.,) sequences was detectable in the LA glands by a specific cDNA probe. Subsequent incubation of the LA glands for 3 days in medium containing insulin and prolactin or insulin and cortisol failed to elicit mRNAesn above the basal level, indicating that neither prolactin nor cortisol alone can support casein gene expression.However, an increase in mRNA. levels was observed when the 3-day incubation with insulin and cortisol or insulin and prolactin was followed by 3 days of culture in presence of insulin, prolactin, and cortisol. When a 3-day incubation with insulin and prolactin was followed by 3 days in insulin and cortisol medium, mRNAes. levels in the gland remained similar to the basal level. However, a 20-fold increase in the mRNAesn levels ensued when the LA glands were sequentially incubated for 3 days in insulin and cortisol and then for another 3 days in insulin and prolactin medium. After a preincubation in insulin and cortisol medium, the LA glands retained residual cortisol during subsequent incubation in insulin and prolactin medium, and the mRNAes. levels in these glands were related to the level of residual cortisol present. When mRNAesn and the residual cortisol level reached a minimum, addition of fresh cortisol to the medium caused a 20-fold increase in the mRNAesn levels. This indicates that cortisol is a limiting factor in insulin and prolactin medium and its presence is absolutely required for casein gene expression.The requirement that prolactin and cortisol be present for lactogenesis was delineated over 2 decades ago (1, 2). Since then, numerous studies have shown that, during lactation, a marked increase of mammary cell RNA and protein, including casein, is dependent upon stimulation by prolactin and cortisol (3, 4). We have shown that cortisol is required for the maintenance of casein-synthesizing polysomes, poly(A)+RNA synthesis, and casein mRNA (mRNAsn) accumulation in the lactating mammary gland of the mouse (5-7). Moreover, a regulatory action of the glucocorticoid on transcription of the casein gene in the mammary gland in vivo has been demonstrated (7). However, complexities in the animal limit elucidation of the discrete role of polypeptide and steroid hormones which regulate specific expression of the casein gene in breast cells.Fragments of mammary tissue from pregnant mice were demonstrated to be capable of synthesizing casein in a culture medium containing the lactogenic hormones plus insulin (8). This provided an in vitro model for studying molecular responses of the mammary cells to prolactin and glucocorticoid action in a chemically defined medium containing insulin, which is needed for viability of the mammary parenchyma in vitro (9). Subsequen...

show abstract

INFLUENCE OF INSULIN ON MAINTENANCE AND SECRETORY STIMULATION OF MOUSE MAMMARY TISSUES BY HORMONES IN ORGAN-CULTURE¹

Cited by 95 publications

References 0 publications

Human Prolactin: Measurement in Plasma by In Vitro Bioassay

Human Prolactin: Measurement in Plasma by In Vitro Bioassay

Hormone-inducible casein messenger RNA in a serum-free organ culture of whole mammary gland

Absolute requirement of glucocorticoid for expression of the casein gene in the presence of prolactin.

Contact Info

Product

Resources

About

INFLUENCE OF INSULIN ON MAINTENANCE AND SECRETORY STIMULATION OF MOUSE MAMMARY TISSUES BY HORMONES IN ORGAN-CULTURE1

Cited by 95 publications

References 0 publications

Human Prolactin: Measurement in Plasma by In Vitro Bioassay

Human Prolactin: Measurement in Plasma by In Vitro Bioassay

Hormone-inducible casein messenger RNA in a serum-free organ culture of whole mammary gland

Absolute requirement of glucocorticoid for expression of the casein gene in the presence of prolactin.

Contact Info

Product

Resources

About

INFLUENCE OF INSULIN ON MAINTENANCE AND SECRETORY STIMULATION OF MOUSE MAMMARY TISSUES BY HORMONES IN ORGAN-CULTURE¹