Sex steroids and growth factors in the regulation of mammary gland proliferation, differentiation, and involution

Lamote, Inge; Meyer, Evelyne; Massart-Leen, Am; Burvenich, Christian

doi:10.1016/j.steroids.2003.12.008

Cited by 93 publications

(80 citation statements)

References 111 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Galactopoietic and lactogenic hormones, IGF, systemic glucocorticoid and progesterone (Ongsakul et al, 1985;Feng et al, 1995;Wilde et al, 1999) are the major systemic factors governing the involution process. The level of systemic lactogenic hormones drops immediately after milking cessation in vivo (Lamote et al, 2004). The importance of the absence of prolactin and somatotropin (ST) for mammary gland involution has been shown in rodents (Marti et al, 1999) and has also been demonstrated for cows in vitro (Accorsi et al, 2002).…”

Section: Impact On Milk Yieldmentioning

confidence: 99%

“…This interruption in hormonal secretions can induce a rapid decline in milk secretion or downregulation of differentiated gene expression in rodents (Vangroenweghe et al, 2005). The mechanisms of survival and apoptosis in the mammary gland by local growth factors were reviewed by Lamote et al (2004). Among the local factors, Lactoferrin, IGFBP-5 and TGF-b1 are known factors that are elevated in stored milk after milk cessation (Schanbacher et al, 1993;Wilde et al, 1999).…”

Section: Altered Dry Periodsmentioning

confidence: 99%

See 1 more Smart Citation

Effects of continuous lactation and short dry periods on mammary function and animal health

Collier

Annen-Dawson

Pezeshki

2012

Animal

View full text Add to dashboard Cite

The dry period is required to facilitate cell turnover in the bovine mammary gland in order to optimize milk yield in the next lactation. Traditionally, an 8-week dry period has been a standard management practice for dairy cows based on retrospective analyses of milk yields following various dry period lengths. However, as milk production per cow has increased, transitioning cows from the nonlactating state to peak milk yield has grown more problematic. This has prompted new studies on dry period requirements for dairy cows. These studies indicate a clear parity effect on dry period requirement. First parity animals require a 60-day dry period, whereas lactations following later parities demonstrate no negative impact with 30-day dry period or even eliminating the dry period when somatotropin (ST) is also used to maintain milk yields. Shortened dry periods in first parity animals were associated with reduced mammary cell turnover during the dry period and early lactation and increased numbers of senescent cells and reduced functionality of lactating alveolar mammary cells postpartum. Use of ST and increased milking frequency postpartum reduced the impact of shortened dry periods. The majority of new intramammary infections occur during the dry period and persist into the following lactation. There is therefore the possibility of altering mastitis incidence by modifying or eliminating the dry period in older parity animals. As the composition of mammary secretions including immunoglobulins may be reduced when the dry period is reduced or eliminated, there is the possibility that the immune status of cows during the peripartum period is influenced by the length of the dry period.

show abstract

Section: Impact On Milk Yieldmentioning

confidence: 99%

Section: Altered Dry Periodsmentioning

confidence: 99%

Effects of continuous lactation and short dry periods on mammary function and animal health

Collier

Annen-Dawson

Pezeshki

2012

Animal

View full text Add to dashboard Cite

show abstract

“…Therefore, the accelerated decline in yield of pregnant cows is likely regulated by endocrine signals originating from the conceptus. Progesterone, 17b-estradiol (hereafter oestrogen) and prolactin (Prl) are major hormones important for mammary gland function during the pregnancy-lactation cycle (Lamote et al, 2004). Changes in plasma concentrations of these hormones are well described, but it is unclear as to how the bovine mammary gland responds to pregnancy at the cellular level.…”

Section: Introductionmentioning

confidence: 99%

Effect of pregnancy and feeding level on cell turnover and expression of related genes in the mammary tissue of lactating dairy cows

Nørgaard

Sørensen

Theil

et al. 2008

Animal

View full text Add to dashboard Cite

Milk yield is reduced by pregnancy, and the present experiment was conducted to study the biological basis for the negative effect of pregnancy on milk yield. A total of 16 dairy cows were fed at either a normal or a low feeding level (eight cows per treatment), and half of them were inseminated after approximately 3 months of lactation and the other half were not inseminated. Mammary biopsies were taken at approximately 9 months of lactation. The milk yield of pregnant cows was reduced by 2.6 kg/day, and lactation persistency was reduced already from the time of insemination. Low feeding level reduced the milk yield by 9.8 kg/day from week 8 to week 39 of lactation, whereas no interaction between pregnancy and feeding level was found. Cell proliferation (Ki-67) and apoptosis (terminal deoxynucleotidyl transferase dUTP nick end labeling, TUNEL) were unaffected by feeding level, and pregnancy tended to reduce cell proliferation but had no effect on apoptosis. Reduced cell proliferation may explain the reduced lactation persistency in pregnant cows. Transcription of oestrogen receptor a, progesterone receptor A and B, and long and short isoforms of the prolactin receptor were higher in pregnant cows compared with non-pregnant cows. Feeding level did not mediate changes in transcription of genes. Transcription of other cell-turnover-related genes (IGF-I, IGF binding protein-5, caspase-3) as well as genes related to the secretory activity of the cells (a-lactalbumin and acetyl CoA carboxylase a) was not affected by pregnancy or by feeding level.

show abstract

“…In addition to physical changes, such as mammary gland growth [19] and milk production [29], a number of concomitant changes occur in the CNS to support a new suite of physiological processes and behaviors that include nursing, nurturing, and protective behaviors [31]. The hypothalamus and preoptic area (including nucleus accumbens) are regions implicated in the control of a range of maternal or parental behaviors [31] and alterations in structure and gene expression in these regions during lactation have been reported.…”

Section: Introductionmentioning

confidence: 99%

Gene array profiling of large hypothalamic CNS regions in lactating and randomly cycling virgin mice

Gammie

Hasen

Awad³

et al. 2005

Molecular Brain Research

View full text Add to dashboard Cite

A dramatic example of neuronal and physiological plasticity in adult mammals occurs during the transition from a non-maternal to a maternal, lactating state. In this study we compared gene expression within a large continuous region of the CNS involved in maternal behaviors (hypothalamus, preoptic regions, and nucleus accumbens) between lactating (L) (postpartum Day 7) and randomly cycling virgin (V) outbred mice. Using high density oligonucleotide arrays representing 11,904 genes, two statistical algorithms were used to identify significant differences in gene expression: robust multi array (p < 0.001) (n = 92 genes) and significance analysis of microarrays using a 10% false discover rate (n = 114 genes). 27 common genes were identified as significant using both techniques. A subset of genes (n = 5) were selected and examined by real-time PCR. Our findings were consistent with previous published work. For example, neuropeptide Y (NPY) and proenkephalin were elevated in L mice, whereas POMC was decreased. Increased levels of NPY Y2 receptor and polo-like kinase and decreased levels of endothelin receptor type b in L mice are examples of novel gene expression changes not previously identified. Expression differences occurred in broad classes. Together, our findings provide possible new material on gene expression changes that may support maternal behaviors. The advantages and drawbacks of sampling large CNS regions using arrays are discussed.

show abstract

Sex steroids and growth factors in the regulation of mammary gland proliferation, differentiation, and involution

Cited by 93 publications

References 111 publications

Effects of continuous lactation and short dry periods on mammary function and animal health

Effects of continuous lactation and short dry periods on mammary function and animal health

Effect of pregnancy and feeding level on cell turnover and expression of related genes in the mammary tissue of lactating dairy cows

Gene array profiling of large hypothalamic CNS regions in lactating and randomly cycling virgin mice

Contact Info

Product

Resources

About