Effects of two different forage sources on mammary gland growth, mammary cell turnover and activity in early lactation dairy cows

2015 ◽  
Vol 55 (5) ◽  
pp. 630 ◽  
Author(s):  
Tong Qin ◽  
Haoyu Wang ◽  
Dengpan Bu ◽  
Haisheng Hao ◽  
Dong Wang ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Mammary Gland ◽  
Dairy Cows ◽  
Milk Proteins ◽  
Secretory Activity ◽  
Early Lactation ◽  
Cell Turnover ◽  
Mammary Cell ◽  
Proliferation And Apoptosis ◽  
Dietary Treatments

The objective of this study was to evaluate the effects of two different forage sources on mammary gland growth, mammary cell turnover and activity in early lactation dairy cows. Twelve early lactation cows were randomly assigned to a CS (33.8% corn straw as sole forage) or MF diet (3.7% Chinese wildrye + 28.4% alfalfa hay + 26.5% corn silage as mixed forage). All cows were fed from Week –3 to Week 8, and mammary biopsies were taken on 16 days postpartum. Mammary cell proliferation and apoptosis were determined by immunohistology, and genes expression in mammary were detected by real-time PCR. Results showed that cell proliferation, gene expression of milk proteins and proteins involved in the synthesis of milk components did not differ between two dietary treatments (P > 0.05). However, cows fed the MF diet had a higher IGF-1 receptor (IGF-1R) expression (P = 0.02), and lower rate of cell apoptosis (P = 0.003) relative to cows fed the CS diet. Collectively, these results suggest that the mammary secretory activity probably was not affected by the dietary treatments, but high quality and mixed forages led to the increased expression of IGF-1R and a larger number of cells in mammary glands, which may be responsible for the higher milk production in early lactation dairy cows.

Sensitivity of mammary secretory cell turnover to protein restriction and re-alimentation during early lactation

1997 ◽  
Vol 1997 ◽  
pp. 130-130
Author(s):  
M.G. Goodwill ◽  
N.S. Jessop ◽  
J.D. Oldham
Keyword(s):  
Cell Proliferation ◽  
Mammary Gland ◽  
Milk Production ◽  
Secretory Cell ◽  
Protein Restriction ◽  
Secretory Cells ◽  
Early Lactation ◽  
Cell Turnover ◽  
Lactational Performance

Milk production depends on both the number and activity of secretory cells within the mammary gland. Our earlier work showed the sensitivity of lactational performance to changes in diet during lactation (Goodwill et al, 1996). This study investigated the influence of protein undernutrition and re-alimentation on secretory cell proliferation and death in the mammary gland of rats during early lactation.

scholarly journals Effects of nutrient restriction on mammary cell turnover and mammary gland remodeling in lactating dairy cows

2011 ◽  
Vol 94 (9) ◽  
pp. 4623-4635 ◽  
Author(s):  
F. Dessauge ◽  
V. Lollivier ◽  
B. Ponchon ◽  
R. Bruckmaier ◽  
L. Finot ◽  
...  
Keyword(s):  
Mammary Gland ◽  
Dairy Cows ◽  
Nutrient Restriction ◽  
Cell Turnover ◽  
Lactating Dairy Cows ◽  
Mammary Cell

scholarly journals Characterization and biological activity of relaxin in porcine milk

Reproduction ◽  
2011 ◽  
Vol 141 (3) ◽  
pp. 373-380 ◽  
Author(s):  
Amy-Lynn Frankshun ◽  
Teh-Yuan Ho ◽  
David C Reimer ◽  
Joseph Chen ◽  
Salamia Lasano ◽  
...  
Keyword(s):  
Mammary Gland ◽  
Milk Proteins ◽  
Immunoblot Analysis ◽  
Mammary Tissue ◽  
Early Lactation ◽  
Maternal Circulation ◽  
A Site ◽  
Porcine Milk ◽  
Primary Form

A lactocrine mechanism for delivery of maternally derived relaxin (RLX) into the neonatal circulation as a consequence of nursing was proposed for the pig. Immunoreactive RLX was detected in colostrum and in the serum of newborn pigs only if they were allowed to nurse. Milk-borne RLX concentrations are highest during early lactation (9–19 ng/ml), declining to <2 ng/ml by postnatal day 14. Whether milk-borne RLX is bioactive is unknown. Evidence that RLX concentrations in milk are higher than in maternal circulation in several species suggests the mammary gland as a site of local RLX production. It is unknown whether the porcine mammary gland is a source of RLX. Therefore, objectives were to evaluate RLX bioactivity in porcine milk during the first 2 weeks of lactation, identify the form of RLX in porcine milk, and determine whether mammary tissue from early lactation is a source of milk-borne RLX. Milk RLX bioactivity was determined using anin vitrobioassay in which cAMP production by human embryonic kidney (HEK293T) cells transfected with the human RLX receptor (RXFP1) was measured. RLX bioactivity was highest at lactation day (LD) 0, decreasing to undetectable levels by LD 4. Immunoblot analysis of milk proteins revealed an 18 kDa band, indicating proRLX as the primary form of RLX in porcine milk. ProRLX protein and transcripts were detected in porcine mammary tissue on LD 0 and 7. Results support the lactocrine hypothesis by defining the nature and a potential source for bioactive proRLX in porcine colostrum/milk.

scholarly journals Activation of retinoblastoma protein in mammary gland leads to ductal growth suppression, precocious differentiation, and adenocarcinoma

2002 ◽  
Vol 156 (1) ◽  
pp. 185-198 ◽  
Author(s):  
Zhe Jiang ◽  
Eldad Zacksenhaus
Keyword(s):  
Cell Proliferation ◽  
Mammary Gland ◽  
Cellular Proliferation ◽  
Mammary Epithelium ◽  
Specific Effect ◽  
Mouse Mammary Gland ◽  
Transient Activation ◽  
Proliferation And Apoptosis

The retinoblastoma (Rb) tumor suppressor controls cellular proliferation, survival, and differentiation and is functionally inactivated by mutations or hyperphosphorylation in most human cancers. Although activation of endogenous Rb is thought to provide an effective approach to suppress cell proliferation, long-term inhibition of apoptosis by active Rb may have detrimental consequences in vivo. To directly test these paradigms, we targeted phosphorylation-resistant constitutively active Rb alleles, RbΔKs, to the mouse mammary gland. Pubescent transgenic females displayed reduced ductal elongation and cell proliferation at the endbuds. Postpuberty transgenic mice exhibited precocious cellular differentiation and β-casein expression and extended survival of the mammary epithelium with a moderate but specific effect on the expression of E2F1, IGF1Rα, and phospho–protein kinase B/AKT. Remarkably, ∼30% RbΔK transgenic females developed focal hyperplastic nodules, and ∼7% exhibited full-blown mammary adenocarcinomas within 15 mo. Expression of the RbΔK transgene in these mammary tumors was reduced greatly. Our results suggest that transient activation of Rb induces cancer by extending cell survival and that the dual effects of Rb on cell proliferation and apoptosis impose an inherent caveat to the use of the Rb pathway for long-term cancer therapy.

scholarly journals Whole-body fluxes and partitioning of amino acids to the mammary gland of cows fed fresh pasture at two levels of intake during early lactation

2003 ◽  
Vol 90 (2) ◽  
pp. 271-281 ◽  
Author(s):  
D. Pacheco ◽  
M.H. Tavendale ◽  
G. W. Reynolds ◽  
T. N. Barry ◽  
J. Lee ◽  
...  
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Mammary Gland ◽  
Dairy Cows ◽  
Milk Protein ◽  
Essential Amino Acids ◽  
Whole Body ◽  
Early Lactation ◽  
Isoleucine Leucine ◽  
Ad Libitum

The utilisation of essential amino acids (EAA) by the mammary gland of lactating dairy cows fed fresh forages was studied to provide basic information useful in designing strategies to increase the production of milk protein from pasture-fed dairy cows. The relationship between the flux of EAA in the whole body and their uptake by the mammary gland was determined in four cows in early lactation (length of time in milk 44 (SD 14·5) d) producing 21 (SD 4·0) kg milk/d. The cows were maintained in metabolism stalls and fed fresh perennial ryegrass (Lolium perenne) and white clover (Trifolium repens) pasturead libitumor restricted to 75 %ad libitumintake. The whole-body fluxes of amino acids (AA) were measured using an arterio-venous infusion of universally13C-labelled AA. Whole-body fluxes of fourteen AA were estimated. Isotope dilution indicated that mammary utilisation accounted for one-third of the whole-body flux of EAA, with individual AA ranging between 17 and 35 %. Isoleucine, leucine, valine and lysine were the EAA with the greatest partitioning towards the mammary gland (up to 36 % of the whole-body flux), which could reflect a potentially limiting effect on milk protein synthesis. In the case of AA with low partitioning to the mammary gland (for example, histidine), it is suggested that non-mammary tissues may have priority over the mammary gland and therefore the supply of this AA may also limit milk protein synthesis.

scholarly journals Tissue homeostasis in sponges: quantitative analysis of cell proliferation and apoptosis

2021 ◽  
Author(s):  
Nikolai P Melnikov ◽  
Fyodor V Bolshakov ◽  
Veronika S Frolova ◽  
Ksenia V Skorentseva ◽  
Alexander V Ereskovsky ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Tissue Homeostasis ◽  
Laser Scanning Microscopy ◽  
Mitochondrial Outer Membrane ◽  
Cell Cycle Distribution ◽  
Apoptotic Cells ◽  
Cell Turnover ◽  
Mitochondrial Outer Membrane Permeabilization ◽  
Proliferation And Apoptosis

Background: Tissues of multicellular animals are maintained due to a tight balance between cell proliferation and programmed cell death. Phylum Porifera is an early branching group of metazoans essential to understanding the key mechanisms of tissue homeostasis. This paper is dedicated to the comparative analysis of proliferation and apoptosis in intact tissues of two sponges belonging to distinct Porifera lineages, Halisarca dujardinii (class Demospongiae) and Leucosolenia variabilis (class Calcarea). Results: Labeled nucleotides EdU and anti-phosphorylated histone 3 antibodies reveal a considerable number of cycling cells in intact tissues of both species. The main type of cycling cells are choanocytes - flagellated cells of the aquiferous system. The rate of proliferation remains constant in areas containing choanoderm. Cell cycle distribution assessed by the quantitative DNA stain reveals the classic cell cycle distribution curve. During EdU pulse-chase experiments conducted in H. dujardinii, the contribution of the choanocytes to the total amount of EdU-positive cells decreases, while contribution of the mesohyl cells increases. These findings could indicate that the proliferation of the choanocytes is not solely limited to the renewal of the choanoderm, and that choanocytes may participate in the general cell turnover through migration. The number of apoptotic cells in intact tissues of both species is insignificant. In vivo studies in both species with TMRE and CellEvent Caspase-3/7 indicate that apoptosis might be independent of mitochondrial outer membrane permeabilization. Conclusions: A combination of confocal laser scanning microscopy and flow cytometry provides a quantitative description of cell turnover in intact sponge tissues. Intact tissues of H. dujardinii (Demospongiae) and L. variabilis (Calcarea) are highly proliferative, indicating either high rates of growth or cell turnover. Although the number of apoptotic cells is low, apoptosis could still be involved in the regular cell turnover.

scholarly journals Effects of increased milking frequency on metabolism and mammary cell proliferation in Holstein dairy cows

2010 ◽  
Vol 93 (2) ◽  
pp. 565-573 ◽  
Author(s):  
F. Soberon ◽  
J.L. Lukas ◽  
M.E. Van Amburgh ◽  
A.V. Capuco ◽  
D.M. Galton ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Dairy Cows ◽  
Mammary Cell ◽  
Milking Frequency ◽  
Holstein Dairy Cows

scholarly journals PROLINE SUPPLY FOR EFFICIENT NITROGEN UTILIZATION BY LACTATING RUMINANTS

1984 ◽  
Vol 64 (5) ◽  
pp. 285-286 ◽  
Author(s):  
I. BRUCKENTAL ◽  
EUGENIA ALUMOT
Keyword(s):  
Mammary Gland ◽  
Dairy Cows ◽  
Key Words ◽  
Dietary Protein ◽  
Nitrogen Utilization ◽  
Mammary Tissue ◽  
Early Lactation ◽  
Rumen Degradation ◽  
Arginine Uptake

To prove the sparing action of proline on arginine utilization by the mammary gland, proline was administered to the duodenum of goats in early lactation. As found previously in mid-lactation, arginine uptake by the mammary gland dropped significantly due to proline addition. Cow mammary tissue was cultured in media with increasing concentrations of proline. The radioactivity of proline formed from [U-14C] arginine was measured in hydrolysates of casein synthesized by the gland. Increasing proline concentrations caused a corresponding decrease in proline labelling. The addition of proline, protected against rumen degradation, may save dietary protein in the ration of high-producing dairy cows. Key words: Proline, lactating ruminants

scholarly journals Mammary Cell Turnover under High Temperature during the Dry Period in Dairy Cows

2011 ◽  
Vol 24 (4) ◽  
pp. 485-492
Author(s):  
Xiaoqing Peng ◽  
Lin Lu ◽  
Yan Li ◽  
Peishi Yan
Keyword(s):  
High Temperature ◽  
Dairy Cows ◽  
Cell Turnover ◽  
Dry Period ◽  
Mammary Cell
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