Differential Responsiveness to Hormones of<i>C3H</i>and<i>A</i>Mouse Mammary Tissues in Organ Culture

Rivera, Evelyn M.

doi:10.1210/endo-74-6-853

Cited by 60 publications

(22 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The addition of human male pooled plasma in concentrations of 30% to all standards increased the sensitivity of the assay. 31.5% of assays. The effective sensitivity in most assays is 5 ng/ml or 0.14 mU/ml.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

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: Resultsmentioning

confidence: 99%

“…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

show abstract

“…shown to differ from primary induction in a number of ways depending on the system; secondary induction is often faster (1, 2), greater (3), more sensitive to the inducer (2,4), and less specific in the type of inducer required (5) than primary induction. In particular, this laboratory has reported (2) that the induction of lactose synthetase activity in vitro in mammary gland explants from parous mice (secondary induction) was faster and required lesser amounts of hormones than in those from virgins (primary induction).…”

Section: S Econdary Induction Of Differentiation Has Beenmentioning

confidence: 99%

Enhanced Endocrine Sensitivity in Mouse Mammary Glands: Hormonal Requirements for Induction and Maintenance*

Bolander

1984

Endocrinology

View full text Add to dashboard Cite

This laboratory has previously shown that mammary epithelium from pregnant and parous mice are 5-7 times more sensitive in vitro to insulin, cortisol, and PRL than tissue from virgins, with respect to lactose synthetase activity. In the present studies, virgin mice were treated for 2 weeks with either progesterone or a pituitary allograft to increase PRL levels, and the mammary explants exhibited the same heightened sensitivity to all three hormones that was noted in pregnant animals. Treatment with estradiol or T4 was without effect. However, this effect was transient, since the tissue lost its elevated hormonal responsiveness 4 weeks after progesterone withdrawal, suggesting that the permanent effect seen in nonpregnant nonlactating parous mice involves a more complex series of events than simply elevated progesterone or PRL levels. Even tissue from parous mice reverted to a reduced insulin and PRL sensitivity, if the tissue was initially cultured in the absence of any hormones. Although the increased sensitivity to cortisol did appear to be permanent under the culture conditions used, the maintenance of a heightened insulin responsiveness required the continuous presence of insulin, cortisol, and PRL, while that for PRL needed at least two of these three hormones. In summary, progesterone and/or PRL may be partly responsible for the increased hormonal sensitivity first manifest during pregnancy, but a normal endocrine milieu is required to maintain this responsiveness in vitro.

show abstract

“…

…”

mentioning

confidence: 99%

Growth Hormone Activity and Dna Synthesis in Mammary Organ Culture

Rivera¹,

Cummins²

1970

Journal of Endocrinology

View full text Add to dashboard Cite

Insulin, adrenal corticosteroid, and prolactin are minimal hormonal requirements for the development of secretion in cultures of pregnant mouse mammary gland (Rivera, 1964;Juergens, Stockdale, Topper & Elias, 1965). Augmentation of the rate of DNA synthesis is one of the hormone-initiated events associated with the developmental process, and this is primarily due to insulin (Juergens et al. 1965). Recently, human growth hormone (HGH) and human chorionic somatomammotrophin (HCS) have been shown to act similarly to prolactin in inducing functional changes in mammary organ cultures (Forsyth, 1967;Turkington, 1968a;Rivera, 1970). These hormones, having similar intrinsic prolactin-like activities, contain considerably more growth hormone activity than prolactin, and it was of interest to assess their growth-promoting activity in mammary gland cultures.The growth hormone activity of the HGH (Upjohn lot no. 8717-DAD-100.3) was 2\m=.\5 units/mg. assayed by the 8-day 'body-weight gain' test against bovine growth hormone (NIH lot no. B-10). The HCS (Upjohn lot no. 8985-AJP-138.3) was equivalent to an HGH standard containing 1\m=.\6 units/mg. as determined by the complement fixation inhibition test. The growth hormone activity of the ovine prolactin (NIH lot no. P-S-7) was 0*0039 units/mg. as determined by the 10-day 'body-weight gain' test.Hormones were added to basal culture Medium 199 (BBL, Bioquest, Md.) indivi¬ dually or in various combinations with insulin and corticosterone as shown in Fig. 1. The final concentration of each protein hormone was 5 /ig./ml. and of corticosterone, 1 /ig./ml. For each group, in triplicate, 50 mammary expiants were dissected from two nulliparous Swiss albino mice in midpregnancy (10-13 days) and prepared as organ cultures (Mayne, Barry & Rivera, 1966). Cultures were maintained for 24 and 48 hr. at 37°, pH 7*4-7*6, under a constant flow of humidified 95% 02:5% C02.[3H]Thymidine (sp. act. 6*7 c/m-mole, 0*5 /ic/ml.), was added to the medium during the last 4 hr. of culture. At termination, the expiants in each group were analysed by the diphenylamine reaction (Burton, 1956) and radioactivity counted in a liquid scintillation counter.The results in Fig. 1 are expressed for the experimental groups as a percentage of the insulin-stimulated increase in DNA synthesis, measured as counts/min. of [3H]thymidine incorporated per /ig. DNA. The incorporation due to insulin was twice as great at 24 hr. as at 48 hr. Neither HGH nor HCS alone increased the specific activity of DNA above that obtained with hormone-free medium, which was only 10% of the amount produced by stimulation with insulin. Turkington (1968 ) has also reported that HCS does not stimulate DNA synthesis in mammary expiants.

show abstract

Differential Responsiveness to Hormones ofC3HandAMouse Mammary Tissues in Organ Culture

Cited by 60 publications

References 0 publications

Human Prolactin: Measurement in Plasma by In Vitro Bioassay

Human Prolactin: Measurement in Plasma by In Vitro Bioassay

Enhanced Endocrine Sensitivity in Mouse Mammary Glands: Hormonal Requirements for Induction and Maintenance*

Growth Hormone Activity and Dna Synthesis in Mammary Organ Culture

Contact Info

Product

Resources

About