scholarly journals The differential actions of cortisol on the synthesis and turnover of alpha-lactalbumin and casein and on accumulation of their mRNA in mouse mammary gland in organ culture

1983 ◽  
Vol 212 (2) ◽  
pp. 507-515 ◽  
Author(s):  
Y Nagamatsu ◽  
T Oka
Keyword(s):  
Mammary Gland ◽  
Marked Decrease ◽  
Milk Proteins ◽  
Mammary Glands ◽  
Mouse Mammary Gland ◽  
Marked Enhancement ◽  
Pregnant Mice ◽  
Translatable Mrna ◽  
Casein Synthesis ◽  
Alpha Lactalbumin

Cortisol was previously shown to exert different, concentration-dependent, effects on the accumulation of casein and alpha-lactalbumin in mammary glands from mid-pregnant mice cultured in the presence of insulin and prolactin [Ono & Oka (1980) Cell 19, 473-480]. The present study demonstrated that the addition of 30nM-cortisol to the medium containing insulin and prolactin resulted in a marked enhancement of the rate of synthesis of both alpha-lactalbumin and casein in cultured tissue. The addition of 3 microM-cortisol in combination with insulin and prolactin caused a marked decrease in the rate of alpha-lactalbumin synthesis, but increased casein synthesis substantially. Similar changes were also observed in the amount of translatable mRNA for alpha-lactalbumin and casein in mammary explants cultured with insulin, prolactin and the two concentrations of cortisol. The study of the turnover of the milk proteins in cultured explants showed that virtually all of the casein synthesized remained intact in tissue explants cultured with 3 microM cortisol, whereas about 45% of casein disappeared in 40h from explants cultured with 30nM-cortisol. In contrast, the two concentrations of cortisol did not differentially affect the disappearance of alpha-lactalbumin, which was about 55% in 40h. These results indicate that the concentration-dependent differential actions of cortisol on the accumulation of alpha-lactalbumin and casein are exerted through its effects on the rate of synthesis and turnover of the two proteins as well as on the accumulation of their mRNA species.

scholarly journals TGF beta suppresses casein synthesis in mouse mammary explants and may play a role in controlling milk levels during pregnancy.

1993 ◽  
Vol 120 (1) ◽  
pp. 245-251 ◽  
Author(s):  
S D Robinson ◽  
A B Roberts ◽  
C W Daniel
Keyword(s):  
Mammary Gland ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Milk Proteins ◽  
Tgf Beta ◽  
Pregnant Mice ◽  
Growth Factor Beta ◽  
Beta 2 ◽  
Dose Dependent ◽  
Casein Synthesis

Mammary explants from 14-15-d-pregnant mice synthesize and secrete milk proteins in culture in response to insulin, hydrocortisone, and prolactin. Here we demonstrate that transforming growth factor beta (TGF beta) treatment suppresses, in a dose dependent and reversible manner, the ability of explants to synthesize and secrete milk caseins. TGF beta does not affect the level of casein mRNA within explants but inhibits casein synthesis posttranscriptionally. We also show increased expression of TGF beta 2 and TGF beta 3 in intact mammary gland as pregnancy progresses, with reduced expression of all three TGF betas at the onset of lactation. These findings suggest that endogenously produced TGF beta may limit the accumulation of milk caseins that are produced in the mammary gland during pregnancy.

scholarly journals Effect of starvation and refeeding on polyamine concentrations and ornithine decarboxylase antizyme in mammary gland of lactating rats

1983 ◽  
Vol 212 (1) ◽  
pp. 149-153 ◽  
Author(s):  
M E Brosnan ◽  
R Farrell ◽  
H Wilansky ◽  
D H Williamson
Keyword(s):  
Mammary Gland ◽  
Nucleic Acid ◽  
Ornithine Decarboxylase ◽  
Acid Content ◽  
Marked Decrease ◽  
Mammary Glands ◽  
Nucleic Acid Content ◽  
Decarboxylase Activity ◽  
Ornithine Decarboxylase Activity ◽  
Polyamine Content

Starvation caused a marked increase in putrescine content in mammary gland of lactating rats, together with a marked decrease in activity of ornithine decarboxylase and appearance of measurable ornithine decarboxylase antizyme. 2. Refeeding for 5 h caused disappearance of free antizyme and ornithine decarboxylase activity returned to the value in fed animals. Putrescine concentration remained elevated. 3. There was no significant change in nucleic acid content of mammary gland from starved rats, but spermidine and spermine contents increased significantly. 4. Refeeding for 5 h returned the spermidine content of mammary glands to ‘fed’ values, and significantly decreased the content of spermine, although it did not reach control values. Thus changes in polyamine content of mammary gland in starved rats are clearly dissociated from changes in either RNA content or activities of polyamine-synthetic decarboxylases. 5. Starvation caused a fall in the content of spermidine in liver, with no change in spermine content. Refeeding for 5 h returned the spermidine content to ‘fed’ values.

The inflammatory environment mediated by a high-fat diet inhibited the development of mammary glands and destroyed the tight junction in pregnant mice.

2020 ◽  
Vol 11 (9) ◽  
pp. 8193-8201
Author(s):  
Wenjin Guo ◽  
Juxiong Liu ◽  
Shuang Hou ◽  
Guiqiu Hu ◽  
He Ma ◽  
...  
Keyword(s):  
Mammary Gland ◽  
Tight Junction ◽  
Pregnant Women ◽  
High Fat Diet ◽  
Mammary Glands ◽  
High Fat ◽  
Pregnant Mice

Long-term intake of a high-fat diet seriously affects the health of pregnant women and leads to increased levels of inflammation in the mammary gland.

scholarly journals Δn89β-Catenin Induces Precocious Development, Differentiation, and Neoplasia in Mammary Gland

2001 ◽  
Vol 153 (3) ◽  
pp. 555-568 ◽  
Author(s):  
Alexandra Imbert ◽  
Rachel Eelkema ◽  
Sara Jordan ◽  
Helen Feiner ◽  
Pamela Cowin
Keyword(s):  
Mammary Gland ◽  
Active Form ◽  
Mammary Glands ◽  
Downstream Effectors ◽  
Mouse Mammary Tumor ◽  
Tumor Virus ◽  
Development And Differentiation ◽  
Pregnant Mice ◽  
Ductal Branching

To investigate the role of β-catenin in mammary gland development and neoplasia, we expressed a stabilized, transcriptionally active form of β-catenin lacking the NH2-terminal 89 amino acids (ΔN89β-catenin) under the control of the mouse mammary tumor virus long terminal repeat. Our results show that ΔN89β-catenin induces precocious lobuloalveolar development and differentiation in the mammary glands of both male and female mice. Virgin ΔN89β-catenin mammary glands resemble those found in wild-type (wt) pregnant mice and inappropriately express cyclin D1 mRNA. In contrast to wt mammary glands, which resume a virgin appearance after cessation of lactation, transgenic mammary glands involute to a midpregnant status. All transgenic females develop multiple aggressive adenocarcinomas early in life. Surprisingly, the ΔN89β-catenin phenotype differs from those elicited by overexpression of Wnt genes in this gland. In particular, ΔN89β-catenin has no effect on ductal side branching. This suggests that Wnt induction of ductal branching involves additional downstream effectors or modulators.

AN IN-VITRO BIOASSAY FOR PROLACTIN BASED ON STIMULATION OF CASEIN SYNTHESIS BY A DISPERSED CELL PREPARATION FROM MOUSE MAMMARY GLAND

1974 ◽  
Vol 62 (3) ◽  
pp. 463-472 ◽  
Author(s):  
W. A. BULLOUGH ◽  
M. WALLIS
Keyword(s):  
Mammary Gland ◽  
Response Curve ◽  
Mouse Mammary Gland ◽  
Placental Lactogen ◽  
Cell Preparation ◽  
In Vitro Bioassay ◽  
Mammary Gland Cells ◽  
Casein Synthesis ◽  
Stimulation Of

SUMMARY An in-vitro bioassay for prolactin has been devised, based on the stimulation of casein synthesis in a mouse mammary gland preparation. Dispersed mammary gland cells were superior to intact explants for this purpose. Casein synthesis by dispersed cells was stimulated by added prolactin, and a linear log dose—response curve was established (for the range 5–20 μg prolactin/ml). The precision of the assay was high (λ = 0·10–0·15). Sensitivity was rather low, but could be improved by increasing the concentration of amino acids in the medium. The response to prolactin was not influenced by thyroxine, adrenocorticotrophin or oestradiol, but thyrotrophin appeared to inhibit it slightly. Both human placental lactogen and bovine growth hormone showed lactogenic activity in the assay.

Effect of prolactin on 2-deoxyglucose uptake in mouse mammary gland explants

1992 ◽  
Vol 262 (5) ◽  
pp. E627-E630 ◽  
Author(s):  
B. J. Peters ◽  
J. A. Rillema
Keyword(s):  
Protein Synthesis ◽  
Mammary Gland ◽  
Glucose Uptake ◽  
Glucose Oxidation ◽  
Actinomycin D ◽  
Mouse Mammary Gland ◽  
Temporal Response ◽  
Pregnant Mice ◽  
Glucose Analogue ◽  
Stimulation Of

These studies were carried out to explore the possible effect of prolactin (PRL) on glucose uptake into culture mammary gland explants derived from 12- to 14-day pregnant mice. PRL was found to stimulate an increased rate of uptake of a nonmetabolized glucose analogue, 2-[3H]deoxyglucose, into cultured mammary tissues. The onset of this response was 16 h after the addition of PRL, and the response persisted for at least 24 h. A similar temporal response was observed when the PRL stimulation of [14C]glucose oxidation to 14CO2 was determined. The lowest PRL concentration that elicited a stimulation of 2-deoxyglucose uptake was 20 ng/ml, and a maximum response occurred with PRL at a concentration of 250 ng/ml. Ongoing protein synthesis appears to be essential for PRL to express its effect on 2-deoxyglucose transport since cyclohexamide, puromycin, and actinomycin D abolished the PRL response. It is also apparent that the PRL stimulation of 2-deoxyglucose involves activation of a specific carrier-mediated uptake transport system, since the rate of uptake of L-glucose into mouse mammary gland explants was unaffected by PRL.

Sign in / Sign up

Export Citation Format

Share Document