The Experts below are selected from a list of 285 Experts worldwide ranked by ideXlab platform
Peter E. Hartmann - One of the best experts on this subject based on the ideXlab platform.
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Short-term rate of Milk Synthesis and expression interval of preterm mothers.
Archives of Disease in Childhood-fetal and Neonatal Edition, 2019Co-Authors: Leon R. Mitoulas, Jacqueline C. Kent, Peter E. Hartmann, Karen Simmer, Donna T. GeddesAbstract:Aim To determine the impact of the pumping regimes of women with preterm infants on the daily Milk production, and on the short-term rate of Milk Synthesis during early lactation to support evidence-based recommendations for optimising Milk production. Methods Mothers of preterm infants (n=25) recorded start time, finish time and expression volumes from every breast expression on days 10, 15–20 postpartum. Results Expressing more often than five times per day did not result in a significant increase in daily Milk production. Milk volume per expression per breast increased for intervals between expressions of between 2and6 hours then reached a plateau when the interval between expression was 7 hours or longer. The short-term rate of Milk Synthesis decreased as the interval between expressions increased until about 7.5 hours at which point it begun to increase (p value associated with interval between expressions^2 Conclusion The strong inverse association between the short-term rate of Milk Synthesis and the interval between expressions for intervals up to 7 hours suggest that the maximum interval between expressions should be 7 hours. Data suggest that, on average, the mothers should express at least five times a day to maximise daily Milk production. Considering inter-individual variation, determination of an individual mother’s maximum interval between expressions that does not compromise the short-term rate of Milk Synthesis will help to optimise daily Milk production while minimising the demands on the mother’s time.
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Hourly Breast Expression to Estimate the Rate of Synthesis of Milk and Fat.
Nutrients, 2018Co-Authors: Jacqueline C. Kent, Peter E. Hartmann, Hazel Gardner, Kevin Murray, Donna T. GeddesAbstract:Objective measurement of the rate of Synthesis of breast Milk and fat in breastfeeding mothers requires test-weighing of each breastfeed and the measurement of each expression from each breast over 24 h, with the collection of Milk samples before and after each breastfeed and expression. We sought an abbreviated technique for measuring these rates of Synthesis. Participants completed a 24-h breastfeeding Milk profile, and expressed their breasts on arrival at the research room and each hour thereafter for 3 h (4 expressions). The hourly rate of Milk Synthesis, as measured by the yield of Milk from the fourth expression, was closely related to the hourly rate of Milk Synthesis calculated from the 24-h Milk profile. The hourly rate of fat Synthesis, calculated from the fat content of small samples of the first and last Milk expressed during the fourth expression, was different from the rate of fat Synthesis calculated from the fat content and volumes of all the breastfeeds and expressions during the 24-h Milk profile. The study confirms the use of an abbreviated technique to measure the rate of breast Milk Synthesis, but is not reliable as a measure of the rate of fat Synthesis for an individual.
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Asynchronous Milk ejection in human lactating breast: Case series
Journal of Human Lactation, 2015Co-Authors: Hazel Gardner, Jacqueline C. Kent, Peter E. Hartmann, Donna T. GeddesAbstract:Background:Milk production is under the influence of autocrine control such that the rate of Milk Synthesis decreases as the breast fills with Milk. Effective elimination of Milk from the alveoli v...
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Measuring Milk Synthesis in Breastfeeding Mothers
Breastfeeding Medicine, 2010Co-Authors: Thomas W. Hale, Karen Simmer, Peter E. HartmannAbstract:Abstract Aim: Breastfeeding mothers expressed their breasts hourly for periods up to 7 hours, without exogenous oxytocin, to determine the consistency of Milk removal and the relationship between the volume of Milk removed and the mother's 24-hour Milk production. Methods: Mothers (n = 20) measured their 24-hour Milk production from each breast by test-weighing their babies at home. Mothers came to the research laboratory for a day visit and expressed Milk from either both or one breast (left or right) for 10–15 minutes, every hour for 2–7 hours. Mothers were not instructed to restrict breastfeeding prior to the first (0-hour) expression. Results: It was found that the Milk volume at 1 hour (59.7 ± 36.5 and 46.5 ± 25.6 mL/hour for the right and left breast, respectively) was significantly (p
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Relationships between symptoms and changes in breast physiology during lactation mastitis.
Breastfeeding Medicine, 2006Co-Authors: Catherine Fetherston, Peter E. HartmannAbstract:OBJECTIVE: The objective was to investigate changes in Milk composition that reflect variations in breast permeability, Milk Synthesis, and immune response in women before, during, and after mastitis. METHODS: Mothers (n = 26) were followed prospectively from day 5 postpartum to the end of their lactation. Milk from each breast, blood, 24-hour urine samples, and data on breast and systemic pathologies were collected at reference intervals during the first 3 months postpartum, daily during the occurrence of any breast inflammation, and 7 days after resolution of symptoms, and was analyzed using mixed-model analysis (repeated measures). RESULTS: There was a significant difference in sodium (p < 0.001), chloride (p < 0.001), serum albumin (p < 0.02) and lactose (p < 0.003) in the breast with mastitis when compared with both the contralateral asymptomatic breast and "healthy" breasts. Inflammation of the whole breast was a significant predictor for a decreased glucose (p < 0.01) and hyperacute systemic symptoms predicted a decrease in Milk glucose (p < 0.03) and an increased lactoferrin (p < 0.05) and sIgA (p < 0.03). CONCLUSIONS: There is an increased breast permeability, reduced Milk Synthesis, and increased concentration of the immune components sIgA and lactoferrin with increasing severity of breast and systemic symptoms. The changes observed in Milk composition during periods of increased breast permeability cannot be solely explained by the current theory of permeability of the paracellular pathway and further research in this area is required.
Kevin John Harvatine - One of the best experts on this subject based on the ideXlab platform.
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night restricted feeding of dairy cows modifies daily rhythms of feed intake Milk Synthesis and plasma metabolites compared with day restricted feeding
British Journal of Nutrition, 2020Co-Authors: I J Salfer, Kevin John HarvatineAbstract:The timing of feed intake can alter circadian rhythms of peripheral tissues. Milk Synthesis displays a daily rhythm across several species, but the effect of feeding time on these rhythms is poorly characterised. The objective of this experiment was to determine if the time of feed intake modifies the daily patterns of Milk Synthesis, plasma metabolites and body temperature in dairy cows. Sixteen lactating Holstein dairy cows were randomly assigned to one of the two treatment sequences in a cross-over design with 17 d periods. Treatments included day-restricted feeding (DRF; feed available from 07.00 to 23.00 hours) and night-restricted feeding (NRF; feed available from 19.00 to 11.00 hours). Cows were Milked every 6 h on the last 7 d of each period, and blood samples were collected to represent every 4 h over the day. Peak Milk yield was shifted from morning in DRF to evening in NRF, while Milk fat, protein and lactose concentration peaked in the evening in DRF and the morning in NRF. Plasma glucose, insulin, NEFA and urea nitrogen concentration fit daily rhythms in all treatments. Night feeding increased the amplitude of glucose, insulin and NEFA rhythms and shifted the daily rhythms by 8 to 12 h ( P
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trans 10 cis 12 cla dose dependently inhibits Milk fat Synthesis without disruption of lactation in c57bl 6j mice
Journal of Nutrition, 2014Co-Authors: Kevin John Harvatine, Megan M Robblee, Stephanie R Thorn, Yves R Boisclair, D. E. BaumanAbstract:BACKGROUND: Trans-10, cis-12 conjugated linoleic acid (10,12 CLA) is a potent inhibitor of Milk fat Synthesis in mammals. In the cow, 10 g/d of 10,12 CLA specifically and reversibly inhibits mammary lipogenesis, whereas substantially higher doses are not specific and cause a generalized inhibition of Milk Synthesis. OBJECTIVE: The objective of this study was to validate a lactating mouse model by establishing the dose response, specificity, and reversibility of the inhibition of Milk fat Synthesis by 10,12 CLA. METHODS: Lactating mice (C57BL/6J) received daily doses of 0 (control), 7, 20, or 60 mg of 10,12 CLA for 5 d during established lactation. A second group of lactating mice was treated with 20 mg/d of 10,12 CLA for 4 d and followed post-treatment to evaluate reversibility. RESULTS: CLA decreased pup growth with a 49% decrease occurring with 60 mg/d of CLA. Milk fat percentage was decreased 11% and 20% with the 7 and 20 mg/d dose, respectively, and all CLA treatments had a decreased concentration of de novo synthesized fatty acids (FAs) in Milk fat. In agreement, 20 mg/d of 10,12 CLA decreased the lipogenic capacity of mammary tissue by 30% and mammary expression of FA synthase (Fasn), sterol response element binding protein 1 (Srebf1), and thyroid hormone responsive spot 14 (Thrsp) by 30-60%, whereas Milk protein percentage and mammary expression of α-lactalbumin (Lalba) were unaltered. This dose of CLA reduced pup growth by nearly 20% and Milk de novo synthesized FAs by >35%, and these effects were completely reversed 5 d after 10,12 CLA treatment was terminated. CONCLUSION: Inhibition of mammary lipogenesis by 10,12 CLA is dose-dependent in the mouse, with a specific and reversible reduction in Milk fat Synthesis at the 20 mg/d dose and additional nonspecific effects on Milk Synthesis at higher CLA doses.
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the daily rhythm of Milk Synthesis is dependent on the timing of feed intake in dairy cows
Physiological Reports, 2014Co-Authors: Whitney L Rottman, Y Ying, Kan Zhou, Paul Allen Bartell, Kevin John HarvatineAbstract:Regulation of the daily rhythm of Milk Synthesis is important to production animals and breastfeeding, but is difficult to observe in nursing animals. The rate of food intake varies over the day and is expected to create a daily rhythm of nutrient absorption. The objective of this study was to determine if the timing of food intake entrains a daily pattern of Milk Synthesis. Seventeen Holstein cows were used in a crossover design. Treatments were ad libitum feeding of a total mixed ration once daily (1× fed) or fed in four equal meals every 6 h (4× fed). Cows were Milked every 6 h the last 7 days of each period. There was a treatment by time of day interaction for Milk and Milk component yield and concentration. Milk fat and protein concentration and yield exhibited a daily rhythm and the amplitude of the rhythm was reduced in 4× fed. In addition, Milk fat percent was higher in 4× fed than 1× fed at three of the four Milking intervals (0.22–0.45% higher) and 4× fed increased daily Milk fat yield. Treatment by time of day interactions were detected for plasma glucose, insulin, and blood urea nitrogen. These variables also fit a cosine function with a 24 h period and the amplitudes of plasma glucose, insulin, and blood urea nitrogen rhythms were decreased by 4× feeding. In conclusion, there is a circadian pattern of Milk Synthesis in the dairy cow that is responsive to the timing of food intake.
Qingzhang Li - One of the best experts on this subject based on the ideXlab platform.
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gsk3β regulates Milk Synthesis in and proliferation of dairy cow mammary epithelial cells via the mtor s6k1 signaling pathway
Molecules, 2014Co-Authors: Xia Zhang, Feng Zhao, Yu Si, Yuling Huang, Cuiping Yu, Na Zhang, Qingzhang LiAbstract:Glycogen synthase kinase 3 (GSK3) is a serine/threonine kinase, whose activity is inhibited by AKT phosphorylation. This inhibitory phosphorylation of GSK3β can in turn play a regulatory role through phosphorylation of several proteins (such as mTOR, elF2B) to promote protein Synthesis. mTOR is a key regulator in protein Synthesis and cell proliferation, and recent studies have shown that both GSK3β and mTORC1 can regulate SREBP1 to promote fat Synthesis. Thus far, however, the cross talk between GSK3β and the mTOR pathway in the regulation of Milk Synthesis and associated cell proliferation is not well understood. In this study the interrelationship between GSK3β and the mTOR/S6K1 signaling pathway leading to Milk Synthesis and proliferation of dairy cow mammary epithelial cells (DCMECs) was analyzed using techniques including GSK3β overexpression by transfection, GSK3β inhibition, mTOR inhibition and methionine stimulation. The analyses revealed that GSK3β represses the mTOR/S6K1 pathway leading to Milk Synthesis and cell proliferation of DCMECs, whereas GSK3β phosphorylation enhances this pathway. Conversely, the activated mTOR/S6K1 signaling pathway downregulates GSK3β expression but enhances GSK3β phosphorylation to increase Milk Synthesis and cell proliferation, whereas inhibition of mTOR leads to upregulation of GSK3β and repression of GSK3β phosphorylation, which in turn decreases Milk Synthesis, and cell proliferation. These findings indicate that GSK3β and phosphorylated GSK3β regulate Milk Synthesis and proliferation of DCMECs via the mTOR/S6K1 signaling pathway. These findings provide new insight into the mechanisms of Milk Synthesis.
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GSK3β regulates Milk Synthesis in and proliferation of dairy cow mammary epithelial cells via the mTOR/S6K1 signaling pathway.
Molecules, 2014Co-Authors: Xia Zhang, Feng Zhao, Yu Si, Yuling Huang, Cuiping Yu, Na Zhang, Qingzhang LiAbstract:Glycogen synthase kinase 3 (GSK3) is a serine/threonine kinase, whose activity is inhibited by AKT phosphorylation. This inhibitory phosphorylation of GSK3β can in turn play a regulatory role through phosphorylation of several proteins (such as mTOR, elF2B) to promote protein Synthesis. mTOR is a key regulator in protein Synthesis and cell proliferation, and recent studies have shown that both GSK3β and mTORC1 can regulate SREBP1 to promote fat Synthesis. Thus far, however, the cross talk between GSK3β and the mTOR pathway in the regulation of Milk Synthesis and associated cell proliferation is not well understood. In this study the interrelationship between GSK3β and the mTOR/S6K1 signaling pathway leading to Milk Synthesis and proliferation of dairy cow mammary epithelial cells (DCMECs) was analyzed using techniques including GSK3β overexpression by transfection, GSK3β inhibition, mTOR inhibition and methionine stimulation. The analyses revealed that GSK3β represses the mTOR/S6K1 pathway leading to Milk Synthesis and cell proliferation of DCMECs, whereas GSK3β phosphorylation enhances this pathway. Conversely, the activated mTOR/S6K1 signaling pathway downregulates GSK3β expression but enhances GSK3β phosphorylation to increase Milk Synthesis and cell proliferation, whereas inhibition of mTOR leads to upregulation of GSK3β and repression of GSK3β phosphorylation, which in turn decreases Milk Synthesis, and cell proliferation. These findings indicate that GSK3β and phosphorylated GSK3β regulate Milk Synthesis and proliferation of DCMECs via the mTOR/S6K1 signaling pathway. These findings provide new insight into the mechanisms of Milk Synthesis.
Xiaohan Yuan - One of the best experts on this subject based on the ideXlab platform.
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Vaccarin promotes proliferation of and Milk Synthesis in bovine mammary epithelial cells through the Prl receptor-PI3K signaling pathway.
European journal of pharmacology, 2020Co-Authors: Yang Yu, Yang Wang, Xiaohan Yuan, Ping Li, Mengmeng YuAbstract:Semen Vaccariae, the seed of Vaccaria segetalis, is traditionally used in East Asian countries for the treatment of breast Milk deficiency, but the underlying molecular mechanism has not been discovered yet. The present study assessed the stimulatory effect of vaccarin, one of the major constituents of Semen Vaccariae, on proliferation of and Milk Synthesis in bovine mammary epithelial cells (BMECs) and explored the corresponding molecular mechanism. Vaccarin affected cell proliferation and Milk fat and protein Synthesis in a concentration-dependent manner, with the best stimulatory effects at 0.5 μg/ml concentration. Vaccarin (0.5 μg/ml) had the similar effects as prolactin (Prl, 0.5 μg/ml) on cell proliferation, Milk fat and protein Synthesis, expression of Cyclin D1, phosphorylation of mechanistic target of rapamycin (mTOR), and expression and maturation of sterol regulatory element binding protein 1c (SREBP-1c). Vaccarin stimulated these signaling pathways via the Prl receptor-phosphatidyl inositol 3-kinase (PI3K) signaling. Vaccarin also concentration-dependently stimulated expression of the Prl receptor, with the best effects at 0.5 μg/ml concentration. In summary, we demonstrate that vaccarin promotes proliferation of and Milk Synthesis in BMECs through the Prl receptor-PI3K signaling, suggesting that vaccarin might be the main active component promoting Milk production of BMECs in Semen Vaccariae.
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Leucine Promotes Milk Synthesis in Bovine Mammary Epithelial Cells via the PI3K-DDX59 Signaling
Journal of Agricultural and Food Chemistry, 2019Co-Authors: Bo Qu, Xiaohan Yuan, Zhen Zhen, Li Zhang, Minghui ZhangAbstract:Leucine is an essential amino acid in the Milk production of bovine mammary glands, but the regulatory roles and molecular mechanisms of leucine are still not known well. This study investigated the roles of leucine on Milk Synthesis and explored the corresponding mechanism in bovine mammary epithelial cells (BMECs). Leucine (0, 0.25, 0.5, 0.75, 1.0, and 1.25 mM) was added to BMECs that were cultured in FBS-free OPTI-MEM medium. Leucine significantly promoted Milk protein and Milk fat Synthesis and also increased phosphorylation of mTOR signaling protein and the protein expression levels of SREBP-1c, with the most significant effects at 0.75 mM concentration. Leucine increased the expression and nuclear localization of DDX59, and loss and gain of gene function experiments further reveal that DDX59 mediates the stimulation of leucine on the mRNA expression variation of mTOR and SREBP-1c genes. PI3K inhibition experiment further detected that leucine upregulated expression of DDX59 and its downstream signal...
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Cyclase-associated protein 1 is a key negative regulator of Milk Synthesis and proliferation of bovine mammary epithelial cells.
Cell Biochemistry and Function, 2019Co-Authors: Xiaohan Yuan, Zhen Zhen, Minghui Zhang, Yanbo Yu, Jinxia AoAbstract:: Adenylyl cyclase-associated protein (CAP) is a highly conserved protein. Previous reports have suggested that CAP1 may be a negative regulator of cellular proliferation, migration, and adhesion and the development of cell carcinomas. The molecular mechanism of CAP1 regulation of downstream pathways, as well as how CAP1 is regulated by environmental stimuli and upstream signalling, is not well understood. In this present study, we assessed the role of CAP1 in Milk Synthesis and proliferation of bovine mammary epithelial cells. Using gene overexpression and silencing methods, CAP1 was found to negatively regulate Milk Synthesis and proliferation of cells via the PI3K-mTOR/SREBP-1c/Cyclin D1 signalling pathway. Hormones, such as prolactin and oestrogen, and amino acids, such as methionine and leucine, stimulate MMP9 expression and trigger CAP1 degradation, and thus, abrogate its inhibition of Synthesis of Milk protein, fat, and lactose by and proliferation of bovine mammary epithelial cells. The results of our study help deepen our understanding of the regulatory mechanisms underlying Milk Synthesis and aid in characterizing the molecular mechanisms of CAP1. Previous reports have suggested that CAP1 is a negative regulator of cellular proliferation and anabolism, but the molecular mechanisms are largely unknown. In this present study, we identified CAP1 as a negative regulator of Milk Synthesis and proliferation of bovine mammary epithelial cells. Our results will deepen our understanding of the regulatory mechanisms underlying Milk Synthesis and aid in exploring the molecular mechanisms of CAP1.
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U2AF65 enhances Milk Synthesis and growth of bovine mammary epithelial cells by positively regulating the mTOR-SREBP-1c signalling pathway.
Cell Biochemistry and Function, 2019Co-Authors: Yanbo Yu, Xiaohan Yuan, Zhen Zhen, Hao Qi, Minghui ZhangAbstract:: U2 snRNP auxiliary factor 65 kDa (U2AF65) is a splicing factor that promotes prespliceosome assembly. The function of U2AF65 in alternative splicing has been identified; however, the essential physiological role of U2AF65 remains poorly understood. In this study, we investigated the regulatory role of U2AF65 in Milk Synthesis and growth of bovine mammary epithelial cells (BMECs). Our results showed that U2AF65 localizes in the nucleus. Treatment with amino acids (Met and Leu) and hormones (prolactin and β-estradiol) upregulated the expression of U2AF65 in these cells. U2AF65 overexpression increased the Synthesis of β-casein, triglycerides, and lactose; increased cell viability; and promoted proliferation of BMECs. Furthermore, our results showed that U2AF65 positively regulated mTOR phosphorylation and expression of mature mRNA of mTOR and SREBP-1c. Collectively, our findings demonstrate that U2AF65 regulates the mRNA expression of signalling molecules (mTOR and SREBP-1c) involved in Milk Synthesis and growth of BMECs, possibly via controlling the splicing and maturation of these mRNAs. U2 snRNP auxiliary factor 65 kDa (U2AF65) is a splicing factor that promotes prespliceosome assembly. The essential physiological role of U2AF65 remains poorly understood. In the present study, we confirmed that U2AF65 functions as a positive regulator of Milk Synthesis in and proliferation of bovine mammary epithelial cells via the mTOR-SREBP-1c signalling pathway. Therefore, our study uncovers the regulatory role of U2AF65 in Milk Synthesis and cell proliferation.
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NUCKS1 is a novel regulator of Milk Synthesis in and proliferation of mammary epithelial cells via the mTOR signaling pathway.
Journal of Cellular Physiology, 2019Co-Authors: Xiaohan Yuan, Jinxia Ao, Zhen Zhen, Minghui Zhang, Meng LiAbstract:: Nuclear ubiquitous casein and cyclin-dependent kinase substrate 1 (NUCKS1) is a highly phosphorylated nuclear protein ubiquitously expressed in vertebrates. NUCKS1 has been reported to be a key chromatin modifier and transcriptional regulator of a number of signaling pathways, but the physiological role and detailed mechanism are still limited. In this study, we assessed the role of NUCKS1 on Milk Synthesis in and proliferation of mammary epithelial cells from a dairy cow. NUCKS1 was located in the nucleus of mammary epithelial cells, and the expression of NUCKS1 was stimulated by amino acids (Met and Leu) and hormones (estrogen and prolactin). Gene function study approaches detected that NUCKS1 positively regulated Milk protein, Milk fat, and lactose Synthesis, and also increased the cell number, cell viability, and cell cycle progression. NUCKS1 mediated the stimulation of amino acids and hormones on the messenger RNA expression of the mechanistic target of rapamycin (mTOR), SREBP-1c, and Cyclin D1. The expression of NUCKS1 is dramatically higher in mouse mammary tissue of lactating period, compared with that in puberty and dry period. Taken together, these results reveal that NUCKS1 is a new mediator of Milk Synthesis in and proliferation of mammary epithelial cells via regulating the mTOR signaling pathway.
P. X. Qi - One of the best experts on this subject based on the ideXlab platform.
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Casein micelle structure: What can be learned from Milk Synthesis and structural biology?
Current Opinion in Colloid and Interface Science, 2006Co-Authors: Harold M. Farrell, E M Brown, Edyth L. Malin, P. X. QiAbstract:At the heart of the skim Milk system are the colloidal casein-calcium-transport complexes termed the casein micelles. The application of physical chemical techniques such as light, neutron, and X-ray scattering and electron microscopy has yielded a wealth of experimental detail concerning the structure of the casein micelle. From these experimental data bases have arisen two conflicting models for the internal structure of the casein micelle. One model emphasizes protein submicellar structures as the dominant feature, while the other proposes that inorganic calcium phosphate nanoclusters serve this function. These models are critically examined in light of our current information regarding the biological processes of protein secretion. In addition two primary tenets of structural biology are applied: that protein structure gives rise to function and that competent protein-protein interactions (associations) will lead to efficient transit through the mammary secretory apparatus. However, a set of complex equilibria governs this process which may be completed only after the final step in the processes: Milking. In this light an overwhelming argument can be made for the formation of proteinacious complexes (submicelles) as the formative agents in the Synthesis of casein micelles in mammary tissue. Whether these submicelles persist in the Milk has been questioned. However, perturbations in micellar equilibria allow for the reemergence of submicellar particles in dairy products such as cheese. Thus protein-protein interactions appear to be important in Milk and dairy products from the endoplasmic reticulum to the cheese cutting board.
