Early mechanical stimulation of the nipple-areola receptors complex promotes the mammary milk ejection function in women delivered by cesarean section

2021 ◽  
Vol 50 (2) ◽  
pp. 38-41
Author(s):  
N. P. Alekseev ◽  
E. V. Omelyanjuk ◽  
N. E. Talalajeva
Keyword(s):  
Mammary Gland ◽  
Caesarean Section ◽  
Cesarean Section ◽  
Mechanical Stimulation ◽  
Post Partum ◽  
Milk Ejection ◽  
The Third ◽  
Milk Flow ◽  
Stimulation Of

Mechanical stimulation and milk ejection from mammary gland in women delivered by caesarean section since 1 day post partum by the breastpump with vacuum and compression stimuli promotes milk ejection function. On the third day postpartum the stimulated mothers had significantly more milk flow reflex peaks than those who were not subjected to stimulation during the 10 min milk ejection session.

α1c- and β2-adrenergic receptor mRNA distribution in the bovine mammary gland detected by competitive RT-PCR

2001 ◽  
Vol 68 (4) ◽  
pp. 699-703 ◽  
Author(s):  
OLGA WELLNITZ ◽  
ANDREAS ZURBRIGGEN ◽  
ROBERT R. FRIIS ◽  
JÜRG W. BLUM ◽  
RUPERT M. BRUCKMAIER
Keyword(s):  
Mammary Gland ◽  
Dairy Cows ◽  
Adrenergic Receptors ◽  
Adrenergic Receptor ◽  
Molecular Techniques ◽  
Milk Ejection ◽  
Milk Flow ◽  
Β Adrenergic Receptors ◽  
Stimulation Of ◽  
Receptor Distribution

Milk ejection and milk removal is considerably influenced by the sympathetic nervous system. Stimulation of α-adrenergic receptors by administration of α-adrenergic agonists inhibits alveolar milk ejection and milk removal in dairy cows due to smooth muscle contraction (Blum et al. 1989; Bruckmaier et al. 1991). However, contraction of the teat in response to α-adrenergic receptor stimulation has no influence on milk flow as long as milk is available in the cistern (Bruckmaier et al. 1997). Therefore, α-adrenergic stimulation causes inhibition of transport of alveolar milk into the cistern. On the contrary, the stimulation of β-adrenergic receptors facilitates milk ejection and milk removal in dairy cows (Bernabé & Peeters, 1980; Bruckmaier et al. 1991) because of muscle relaxation. Therefore, the distribution of α- and β-adrenergic receptors plays an important role in the milkability of dairy cows. However, from these in vivo studies it is not possible to distinguish between the different α1- and α2- and β2-receptor subtypes owing to the non-specific nature of the pharmacological agents used.To date, the precise tissue distribution of these different subtypes, in bovine mammary tissue, is unknown. Using molecular techniques, we were interested in the expression of genes that encode α1c and β2 as a preliminary study towards the understanding of noradrenergic receptor-gene expression and regulation in this important system.In addition, α1c- and β2-adrenergic receptors were determined in front and rear quarters of the mammary gland to investigate differences in receptor distribution within the udder and possible relations between adrenergic receptor distribution and the higher milk flow rates in rear than in front quarters (Rothenanger et al. 1995).

THE MOTILITY AND REACTIVITY OF THE OESTROGENIZED RABBIT UTERUS IN VIVO; WITH COMPARATIVE OBSERVATIONS ON MILK EJECTION

1958 ◽  
Vol 16 (3) ◽  
pp. 237-260 ◽  
Author(s):  
B. A. CROSS
Keyword(s):  
Spinal Cord ◽  
Mammary Gland ◽  
Spinal Anaesthesia ◽  
Dose Range ◽  
Abdominal Muscles ◽  
Mechanical Stimuli ◽  
Milk Ejection ◽  
Thoracic Spinal ◽  
Spontaneous Motility ◽  
Stimulation Of

SUMMARY The spontaneous motility of the intact uterus of spayed oestrogenized rabbits under sodium pentobarbitone anaesthesia has been recorded. Both uteri of each animal behaved similarly, and contractions often appeared to be synchronous. Small changes of load affected the amplitude of contractions, but did not alter uterine responsiveness to neurohypophysial or adrenomedullary hormones. Mid-thoracic section of the spinal cord obliterated spontaneous motility of the uterus; spinal anaesthesia did not. Spontaneous motility persisted for as long as 7 hr after decerebration and removal of the pituitary gland. The threshold dose of oxytocin for activating the oestrogenized uterus was the same as that for the lactating mammary gland, i.e. 1–5 mu. Doses up to 50 mu. usually gave an increase in frequency and amplitude of contractions. In the same dose range vasopressin either had little effect or inhibited spontaneous uterine motility, although milk ejection was stimulated. Slow infusion of oxytocin at rates of 1·5–48 mu./min produced graded increases in the rate and depth of uterine contractions and, at the same time, in similarly treated, lactating animals, rhythmic milk-ejection responses which at the higher rates of infusion merged to give a tetanic (plateau) type of milk ejection. Adrenaline or noradrenaline in doses of 1–5 μg produced diphasic uterine responses, initial contractions being followed by inhibition of spontaneous motility. They also inhibited the uterine, as well as the milk-ejection response to oxytocin injected 10–30 sec later. The inhibitory effect of adrenaline on both organs was about twice that of noradrenaline. The above-mentioned responses to adrenaline and oxytocin could also be elicited by electrical stimulation of the hypothalamus. Stimuli in the dorsal, lateral, perifornical and posterior hypothalamic areas produced effects equivalent to those of 1–5 μg adrenaline on both the uterus and mammary gland. These responses were abolished by mid-thoracic section of the spinal cord or by spinal anaesthesia. In such preparations responses typical of those produced by oxytocin were seen in both organs after stimulation of the paraventricular nuclei, supraoptic nuclei and the hypothalamo-hypophysial nerve pathways of the tuber cinereum and neural stalk. Dilatation of the vagina (or rectum) gave rise to a uterine response similar to that resulting from adrenaline or noradrenaline. The response was abolished by spinal anaesthesia, but not by mid-thoracic spinal section or decerebration. The same stimuli also produced 'bearing down' contractions of the abdominal muscles. Contractions of the uterus could also be elicited by mechanical stimuli, in the absence of functional spinal connexions.

scholarly journals Comparison of maternal milk ejection characteristics during pumping using infant-derived and 2-phase vacuum patterns

2019 ◽  
Vol 14 (1) ◽  
Author(s):  
Hazel Gardner ◽  
Jacqueline C. Kent ◽  
Ching Tat Lai ◽  
Donna T. Geddes
Keyword(s):  
Physiological Response ◽  
Post Partum ◽  
Random Effect ◽  
Individual Variability ◽  
Phase Pattern ◽  
Milk Ejection ◽  
Convenience Sample ◽  
Mixed Effects Modeling ◽  
Milk Flow ◽  
Milk Volume

Abstract Background Milk ejection characteristics remain consistent throughout 12 months of lactation in women who expressed breastmilk with an electric breast pump. In addition these characteristics appear to remain constant when women are breastfeeding or pumping suggesting that milk ejection is a robust physiological response. It is not known whether the stimulation of an infant at the breast in the early post partum period influences milk ejection patterns or whether this is a programmed event. However, as more data become available on the mechanisms involved in infant feeding, pumping patterns mimicking the infant more closely may provide enhanced results. The objective of this study was to compare milk ejection characteristics obtained when using a novel infant-derived pumping pattern with an established 2-phase pattern. Methods A convenience sample of ten lactating mothers, 1 to 40 weeks of lactation with normal milk production were recruited in 2015. Each participated in two pumping sessions in which either a 2-phase pattern or infant-derived pattern were randomly assigned. Milk volume and milk ejection characteristics were recorded and the percentage of available milk removed (PAMR) was calculated. Statistical analysis used linear mixed effects modeling to determine any differences between breasts and pump patterns with the consideration of individual variability as a random effect. Results The number of milk ejections and milk ejection characteristics did not differ between patterns. Milk volumes removed were 53.6 ± 28.5 ml (PAMR 58.2 ± 28.4) for the 2-phase pattern and and 54.2 ± 26.3 ml (PAMR 52.2 ± 22.3) for the infant derived pattern. Peak milk flow rates were positively associated with the available milk (p = 0.0003) and PAMR (p = 0.0001), as was the volume of milk removed during each milk ejection (p = 0.001 and p = 0.0001). Conclusion An experimental pumping pattern designed to resemble infant sucking characteristics did not alter milk ejection characteristics or milk removal parameters compared with an established 2-phase pattern. Theses findings provide further evidence that milk ejection is a robust physiological response.

Effect of stimulation intensity on oxytocin release before, during and after machine milking

2003 ◽  
Vol 70 (3) ◽  
pp. 349-354 ◽  
Author(s):  
Daniel Weiss ◽  
Alen Dzidic ◽  
Rupert M Bruckmaier
Keyword(s):  
Dairy Cows ◽  
Milk Production ◽  
Threshold Level ◽  
Flow Profile ◽  
Milk Ejection ◽  
Machine Milking ◽  
Milk Flow ◽  
Oxytocin Release ◽  
Stimulation Period ◽  
Stimulation Of

Release of oxytocin (OT) is essential for milk ejection in dairy cows (Lefcourt & Akers, 1983; Bruckmaier & Blum, 1998). During milk ejection, alveolar milk is shifted into the cistern, which causes an increase of intracisternal pressure (Bruckmaier et al. 1994). To initiate maximum milk ejection at the start of milking, increasing OT concentration beyond a threshold level is sufficient (Schams et al. 1983). Increasing OT concentration beyond this threshold has no additional effect on intracisternal pressure, i.e., milk ejection (Bruckmaier et al. 1994). Stimulatory effects of milking by hand or by machine or by suckling are well documented (Gorewit et al. 1992; Bar-Peled et al. 1995; Tancin et al. 1995; Bruckmaier & Blum, 1996). At the start of milking, stimulatory effects of machine milking without pre-stimulation or with a manual pre-stimulation and subsequent machine milking cause the release of comparable amounts of OT (Gorewit & Gassman, 1985; Mayer et al. 1985; Bruckmaier & Blum, 1996), whereas the timing of the applied pre-stimulation is important for the shape of the milk flow curve. Should the pre-stimulation period be too short, or absent altogether, the start of the main milk flow is delayed resulting in a bimodal milk flow profile (Bruckmaier & Blum, 1996). Furthermore, the stimulation of only one teat causes an OT release similar to that caused by stimulation of all four teats (Bruckmaier et al. 2001). However, milk production is greater for hand milking or suckling than for machine milking, possibly owing to higher OT concentrations (Gorewit et al. 1992; Bar-Peled et al. 1995).

The Breeding Cycle of the Female Humpback Whale, Megaptera nodosa (Bonnaterre)

1958 ◽  
Vol 9 (1) ◽  
pp. 1 ◽  
Author(s):  
RG Chittleborough
Keyword(s):  
Mammary Gland ◽  
Sex Ratio ◽  
Post Partum ◽  
Humpback Whale ◽  
The Other ◽  
Breeding Cycle ◽  
Sex Ratio At Birth ◽  
Modal Length ◽  
The Third ◽  
Normal Period

The gestation period in the humpback whale is of almost 12 months' duration, most conceptions occurring early in August with parturition at the beginning of the following August. The modal length of calves at birth is 14 ft. The sex ratio at birth is 51.4 per cent. males to 48.6 per cent. females. Twin foetuses are occasionally recorded. There is no preference towards either right or left ovary or uterine cornu with regard to ovulation or pregnancy. The breaking of the umbilical cord at birth is described. The histological appearances of the mammary gland during advanced pregnancy and during lactation are described and illustrated. Upon the evidence presented it is concluded that lactation in this species extends over 104 months, suckling generally commencing in mid August and terminating at the end of the following June. The composition of the milk has been determined during various stages of lactation. Oestrous cycles rarely occur during pregnancy, but examples of ovulation following shortly after parturition, while the females are suckling their calves, are cited. It is shown that when the calf is lost at or soon after birth, oestrous cycles usually recommence at once. Where the calf is suckled for the normal period (10½ months) there is no anoestrous period following the end of lactation as oestrous cycles recommence in July, immediately after (occasionally just before) weaning at the end of June. Three types of breeding cycle are shown for the humpback whale. In the most common cycle, absence of the post-partum ovulation, or its occurrence without conception, results in one calf in 2 years. On the other hand, a successful postpartum ovulation results in two calves in 2 years. In the third type of cycle, loss of the first calf at or just after parturition is balanced by a second pregnancy succeeding immediately afterwards. This results in two pregnancies in 2 years with only one calf reared.

The influence of the milk ejection reflex on the flow rate during the milking of ewes

1969 ◽  
Vol 36 (2) ◽  
pp. 191-201 ◽  
Author(s):  
J. Labussière ◽  
J. Martinet ◽  
R. Denamur
Keyword(s):  
Mammary Gland ◽  
General Anaesthesia ◽  
Flow Rate ◽  
Recording System ◽  
Milk Ejection ◽  
Machine Milking ◽  
Milk Flow ◽  
Milk Ejection Reflex ◽  
Milking Machine ◽  
The Individual

SummaryIn order to obtain more information on the importance of the milk ejection reflex in the lactation of normal ewes, experiments were conducted to determine whether the neuroendocrine reflex is able to modify the parameters which characterize the flow rate of the milk under normal milking conditions.Ewes were allowed to suckle their lambs freely during the 3 days following parturition. They were then milked with a machine and the individual milk production was measured volumetrically at each milking. Different fractions obtained during milking (‘machine milk’, ‘machine strippings’ and ‘hand strippings’), and the milk flow, were measured using a sensitive recording system. In further experiments, machine milking was performed after intravenous administration of oxytocin, during general anaesthesia, and after unilateral or bilateral denervation of the mammary gland.The ewes fell into 2 categories: those giving most of their milk in 1 rapid emission, and those giving it in 2 quite separate emissions. The results indicated that the second emission found in some of the ewes was the milk emptied from the acini by the neuroendocrine ejection reflex. Disappearance of the second emission resulted from the administration of oxytocin before milking—which induces passage of the milk from the acini into the mammary cistern—and also from general anaesthesia or denervation of the mammary gland.

QUANTITATIVE ASPECTS OF RELEASE OF OXYTOCIN BY SUCKLING IN UNANAESTHETIZED RABBITS

1963 ◽  
Vol 44 (4) ◽  
pp. 581-592 ◽  
Author(s):  
Anna-Riitta Fuchs ◽  
Gorm Wagner
Keyword(s):  
Milk Yield ◽  
Essential Role ◽  
Post Partum ◽  
Lactation Period ◽  
Milk Ejection ◽  
Once Daily ◽  
Milk Flow

ABSTRACT A method of estimating oxytocin output following physiological stimuli is described which is applicable to experiments in conscious, undisturbed and unrestrained animals. The method consists of recording the uterine responses in puerperal rabbits with a permanently inserted intrauterine balloon as an index of neurohypophysial activation. Previous work has been confirmed on the essential role of oxytocin in milk ejection in rabbits. Only negligible amounts of milk are obtained by the young without any endogenous or exogenous oxytocin, but normal release of oxytocin can occur in spite of diminished or completely inhibited milk flow. The amount of oxytocin released during suckling depends on the strength of the stimulus in a characteristic fashion, and the strength of stimuli again depends both on the number of young suckling simultaneously and on their physical maturity. In the early puerperium (up to 3–4 days post-partum) each suckling young evokes a response comparable to that of 0.5–1.0 mU of oxytocin injected intravenously, whether suckling alone or together with its litter-mates. Only a few grams of milk are removed by each young at that time. After this period, the suckling of 1 or 2 young separately still elicits the release of only a small amount of oxytocin (1–2 mU), but during suckling of a whole litter from 50 to 100 mU are liberated, which corresponds to 10–15 mU for each young. The full milk yield can only be obtained by each young while suckling simultaneously with the whole litter. The amount of oxytocin released is independent of the duration of suckling, of the quantity of milk available, and of the milk flow. Once lactation has been established, the oxytocin output during suckling on an »once-daily« regime remains fairly constant at least for a large part of the lactation period. It is possible that at the end of the lactating period, the amount secreted during suckling is increased to about 250 mU or even more.

scholarly journals Machine milking of dairy goats during lactation: udder anatomy, milking characteristics, and blood concentrations of oxytocin and prolactin

1994 ◽  
Vol 61 (4) ◽  
pp. 457-466 ◽  
Author(s):  
Rupert M. Bruckmaier ◽  
Chantal Ritter ◽  
Dieter Schams ◽  
Jürg W. Blum
Keyword(s):  
Milk Yield ◽  
Cross Sections ◽  
Dairy Goats ◽  
Milk Ejection ◽  
Blood Concentrations ◽  
Flow Rates ◽  
Machine Milking ◽  
The Third ◽  
Milk Flow

SummaryForty-four goats were milked and milk flow recorded without or with 1 min manual prestimulation in early, mid and late lactation. Ultrasound measurements of cross sections of the whole mammary gland were performed in a water bath. In additional experiments with 15 goats, milk flow was recorded and frequent blood samples were taken for the determination of oxytocin and prolactin concentrations. Milk yield increased from the first to the third lactation and decreased markedly during the course of lactation. Average and peak milk flow rates were closely related to the actual milk yield. The ultrasound cisternal area was 27·4±1·5% of the entire udder half cross section. Milking characteristics were scarcely different without or with prestimulation, although oxytocin was released within 30 s after the start of prestimulation, whereas oxytocin concentrations without prestimulation increased only after the start of milking. Concentrations of prolactin were higher during July and August than in April, and increased similarly with or without prestimulation during milking. In contrast to dairy cows, prestimulation and an opportune release of oxytocin during milking does not significantly influence the course of milk flow in goats, and this is probably because large amounts of cisternal milk allow milk ejection to be induced only after the start of milking without causing bimodal or otherwise reduced milk flow.

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