Inhibition of oxytocin release and milk let-down in postpartum primiparous cows is not abolished by naloxone

2001 ◽  
Vol 68 (4) ◽  
pp. 559-568 ◽  
Author(s):  
WOLF-DIETER KRAETZL ◽  
VLADIMIR TANCIN ◽  
DIETER SCHAMS
Keyword(s):  
Post Partum ◽  
Endogenous Opioids ◽  
Opioid Antagonist ◽  
Milk Ejection ◽  
Brown Swiss ◽  
Machine Milking ◽  
Oxytocin Release ◽  
Naloxone Treatment ◽  
Vaginal Stimulation

About 10% of primiparous cows have no milk ejection during the first milkings after delivery. Therefore, 17 Brown Swiss dairy cows in their first lactation were used to evaluate the extent of disturbed milk let-down and the corresponding oxytocin (OT) plasma values in the 1st 5 days after delivery. The first milking was 9–22 h after parturition and served for classification of the cows to groups with inhibited (INH), bimodal (BIMO) or normal (NOR) milk let-down. The OT plasma levels before the start of manual teat stimulation and machine milking were comparably high during the first milking especially in NOR and BIMO cows. Ten minutes before the second milking (M2), 300 mg of the opioid antagonist naloxone was injected to test whether the disturbance was affected by the action of endogenous opioids on the neurohypophysis. The milk yield was not influenced by the naloxone treatment, and the INH cows had milk ejection only after a vaginal stimulation. Afterwards, the cows were milked twice every day, until the milk let-down and the OT release were unaffected (equal to control milking). Then, at the next milking, the cows were injected with 300 mg morphine 10 min before milking. The central OT release in response to manual teat stimulation and machine milking was completely blocked in all cows, but a vaginal stimulation was able to abolish this block, at least partially, in 16 cows. Thus, morphine produced a milk let-down characteristic as in the INH cows during the first three milkings. For the following milking, the cows were pre-treated with 300 mg naloxone (−15 min) plus 300 mg morphine (−10 min) before milking. The OT release and the milk yields were unaffected when compared with the control milking. This experiment demonstrates that exogenous opioids can affect the central release of OT in a naloxone-reversible manner even very soon after parturition. However, endogenous opioids are probably not the main mediators of disturbed central OT release and alveolar milk ejection in post-partum primiparous cows.

Inhibition of oxytocin release during repeated milking in unfamiliar surroundings: the importance of opioids and adrenal cortex sensitivity

2002 ◽  
Vol 69 (1) ◽  
pp. 63-73 ◽  
Author(s):  
JULIANA MAČUHOVÁ ◽  
VLADIMIR TANČIN ◽  
WOLF-DIETER KRAETZL ◽  
HEINRICH H. D. MEYER ◽  
RUPERT M. BRUCKMAIER
Keyword(s):  
Endogenous Opioids ◽  
Opioid Antagonist ◽  
Control Group ◽  
Research Station ◽  
Milk Ejection ◽  
Milk Flow ◽  
Oxytocin Release ◽  
And Control ◽  
Naloxone Treatment ◽  
Vaginal Stimulation

The aim of this study was to test if the opioid antagonist naloxone has a beneficial effect on normalization of oxytocin (OT) release during repeated milking of cows in unfamiliar surroundings. One control milking without naloxone treatment in all cows was performed in the familiar parlour. For four successive evening milkings, cows were transported to, and milked in, the operating theatre of the research station without (control group) or with naloxone administration (1 mg/kg BW) (naloxone group) before milking. After cessation of spontaneous milk flow, but not before 3 min of milking, vaginal stimulation was applied for 2 min. After milk flow ceased again, 10 IU of OT was injected intravenously to remove the remaining milk including residual milk. Milk flow was recorded continuously and blood samples were collected via a jugular vein cannula at 1-min intervals from 1 min before the start of milking until i.v. injection of OT. The inhibition of milk ejection and its normalization during repeated milking in unfamiliar surroundings was not influenced by naloxone treatment. Concentrations of cortisol and β-endorphin during control milking and all relocations were similar in the naloxone and control groups, although their concentrations were higher after relocations than in the control. Therefore, a role of endogenous opioids in the inhibition of milk ejection in unfamiliar surroundings could not be demonstrated. In addition, the effect of exogenous ACTH1–24 (8 IU, i.v.) on the release of cortisol related to the response of cows milked in unfamiliar surroundings was studied. Cows with totally inhibited milk ejection in response to vaginal stimulation during milking after first relocation had numerically, but not significantly lower cortisol levels (8·8±3·4 ng/ml; AUC/min) in response to ACTH than did cows with at least partial milk ejection (38·7±12·9 ng/ml). Thus animals with a higher adrenal response to ACTH seemed to have less severe inhibition of milk ejection.

EFFECT OF ETHANOL ON UTERINE ACTIVITY DURING SUCKLING IN POST-PARTUM WOMEN

1968 ◽  
Vol 58 (1) ◽  
pp. 133-141 ◽  
Author(s):  
Gorm Wagner ◽  
Anna-Riitta Fuchs
Keyword(s):  
Post Partum ◽  
Blood Alcohol Concentration ◽  
Alcohol Concentration ◽  
Target Organ ◽  
Release Mechanism ◽  
Blood Alcohol ◽  
Milk Ejection ◽  
Oxytocin Release ◽  
Milk Ejection Reflex ◽  
Prior Administration

ABSTRACT Previous experiments indicated that in the rabbit, prior administration of ethyl alcohol inhibits the release of oxytocin elicited by suckling. According to preliminary studies, the same applies also in the human. In the present studies, the effect of ethanol on the milk-ejection reflex in post-partum women was investigated more thoroughly. The milk-ejection reflex was induced by suckling of the infant. The uterine response, recorded by external tocography, was used as a measure of the oxytocin release. Alcohol was administered by mouth as whisky or brandy in suitable dilutions in amounts varying from 0.5 to 1.1 g/kg body weight. By comparison of the uterine response to endogenous (released) and exogenous (injected) oxytocin, it was estimated that about 100–250 mU oxytocin are released by the suckling stimulus in the early puerperium. When alcohol was administered before the application of the stimulus, the release of oxytocin was partially or completely inhibited, but the uterus continued to respond to exogenous oxytocin. As shown previously in the rabbit, the effect of alcohol must thus be on the central release mechanism of oxytocin and not on the peripheral response of the target organ to oxytocin. The degree of inhibition of the oxytocin release was dependent on the alcohol concentration in the blood. With an average blood alcohol concentration of 0.07 per cent the uterine response to suckling during one nursing period was less than half of that observed under normal conditions.

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).

Oxytocin release and lactation performance in Syrian Shami cattle milked with and without suckling

2005 ◽  
Vol 73 (1) ◽  
pp. 28-32 ◽  
Author(s):  
Shehadeh H Kaskous ◽  
Daniel Weiss ◽  
Yassin Massri ◽  
Al-Moutassem B Al-Daker ◽  
Ab-Dallah Nouh ◽  
...  
Keyword(s):  
Milk Yield ◽  
Post Partum ◽  
Lactation Performance ◽  
Machine Milking ◽  
Oxytocin Release ◽  
Daily Milk Yield ◽  
Daily Milk

Oxytocin (OT) release and lactation performance in primiparous Syrian Shami cows were evaluated in response to two different machine milking regimes. Six cows were milked in the presence of the calves (PC) and subsequently suckled, whereas six cows were exclusively machine milked without the presence of their calves (WC) until day 91 post partum. Milk yield and milk constituents were determined weekly. The degree of udder evacuation was determined by the succeeding removal of residual milk. PC released OT during the milking process, whereas in WC no OT release was detected throughout the milking process. Consequently, the residual milk fraction was much lower in PC than in WC (11% v. 58%, P<0·05) and daily milk yield until day 91 post partum was higher in PC than in WC (12·6±0·3 v. 7·1±0·4 kg, P<0·05). In conclusion, Syrian Shami cattle are not suitable to be exclusively machine milked without the presence of their calves.

Early milk ejection, prolonged parturition and periparturient oxytocin release in the pig

1993 ◽  
Vol 57 (03) ◽  
pp. 465-471 ◽  
Author(s):  
H. Castrén ◽  
B. Algers ◽  
A. M. de Passillé ◽  
J. Rushen ◽  
K. Uvnäs-Moberg
Keyword(s):  
Post Partum ◽  
First Birth ◽  
Milk Ejection ◽  
Oxytocin Release ◽  
The Relationship

AbstractPlasma oxytocin was measured in 11 multiparous sows for 13 h after the start of parturition to confirm the existence of early milk ejections and determine whether they were associated with pulsatile oxytocin release. The relationship between oxytocin concentrations and duration of parturition was also analysed. Oxytocin was released in pulses during and after parturition and mean concentrations reached maximum 2 to 4 h after the first birth. Discrete milk ejections occurred during parturition but only 42% of these were associated with oxytocin peaks before 4 hpost partum. After this more than 80% of milk ejections occurred with oxytocin peaks. Sow grunting increased during milk ejections and peak grunt rate increased after parturition. Oxytocin peaks without milk ejections did not lead to an increased rate of grunting. Sows with prolonged parturition had lower basal and peak oxytocin concentrations. During the first 4 h only half of the piglets were born during an oxytocin peak. Discrete milk ejections with oxytocin peaks can occur before parturition is completed. However, during the first 4 hpost partum, basal oxytocin concentrations may be high enough for milk ejection to occur without further oxytocin secretion. Both milk ejection and oxytocin release are necessary for the sow to increase grunt rate. Low oxytocin concentration is associated with prolonged parturition.

Relaxin acts centrally to inhibit oxytocin release during parturition: an effect that is reversed by naloxone

1986 ◽  
Vol 111 (1) ◽  
pp. 99-102 ◽  
Author(s):  
S. A. Jones ◽  
A. J. S. Summerlee
Keyword(s):  
Jugular Vein ◽  
Inhibitory Effect ◽  
Female Rats ◽  
Opioid System ◽  
Opioid Antagonist ◽  
Unoperated Control ◽  
Osmotic Minipumps ◽  
Oxytocin Release ◽  
Naloxone Treatment

ABSTRACT Experiments were carried out to establish whether infusion of relaxin prolongs gestation and labour in the rat by suppressing release of oxytocin, and whether the effects of relaxin on birth could be reversed by the opioid antagonist naloxone. Female rats were implanted with subcutaneous osmotic minipumps for the infusion of purified porcine relaxin into the jugular vein for 84 h from either day 19 or day 20 of gestation. Infusion of relaxin delayed the onset of labour and in those animals which delivered during relaxin infusion, delivery was longer by approximately 45 min. Plasma oxytocin levels 40 min after delivery of the first fetus were 45·25 ± 3·6 pmol/l (mean ± s.d.) in unoperated controls and significantly (P < 0·01) depressed (23·89 ± 3·9) in rats that delivered during infusion of relaxin. Rats that delivered after the infusion of relaxin had finished, gave birth significantly (P < 0·05) faster than controls and plasma oxytocin levels were significantly (P < 0·01) raised (77·87 ±15·9 pmol/l). Naloxone treatment (1 mg/kg; i.m.) given immediately after the delivery of the first fetus reversed the inhibitory effect of relaxin and the interval between successive deliveries was slightly faster than that of controls. Plasma oxytocin levels in relaxin-infused naloxone-treated rats were significantly (P < 0·01) higher than values in unoperated control rats. The results confirm that relaxin suppresses oxytocin release possibly through an opioid system and this may be important in the control of the timing of birth. J. Endocr. (1986) 111, 99–102

The effect of morphine and naloxone on the release of prolactin during machine milking in dairy cows

2003 ◽  
Vol 70 (3) ◽  
pp. 277-282 ◽  
Author(s):  
Vladimír Tančin ◽  
Dieter Schams ◽  
Wolf-Dieter Kraetzl
Keyword(s):  
Dairy Cows ◽  
Opioid Antagonist ◽  
Related Effect ◽  
Brown Swiss ◽  
Machine Milking

The aim of the study was to determine the role of opioids modulating the release of prolactin (PRL) in response to milking in sixteen Brown-Swiss dairy cows. Two experiments were carried out to measure the dose-related effect of morphine and the effect of the opioid antagonist naloxone (NAL), with or without morphine. In the first experiment, six cows were injected (via catheter) on 3 consecutive days after the control milking (0 mg) with 21, 70 and 210 mg morphine-HCl 10 min before the start of the morning milking. The second experiment was divided into two parts. In the first part, four cows were injected after control morning milking with 210 mg morphine, 10 min before the start of the following morning milking. This was followed on the next day by an application of 210 mg NAL (15 min before the start of milking) and 210 mg morphine. In the second part, after control milking for 1 d, six cows were injected with 210 mg NAL 10 min before milking. Morphine at the highest dose tended to stimulate basal PRL levels in the first and second experiments (P<0·10). PRL increased in response to machine milking but morphine did not stimulate its release further. NAL alone, or when given with morphine did not influence the release of PRL in response to machine milking. However, NAL was effective in suppressing the increase in basal levels of PRL caused by morphine. In conclusion, although morphine tended to stimulate basal levels of PRL before milking, the release of PRL during milking seemed not to be regulated by opioids.

Changes in pain threshold during pregnancy and parturition in the sow and the involvement of opioids

1996 ◽  
Vol 1996 ◽  
pp. 32-32
Author(s):  
S. Jarvis ◽  
K. A. McLean ◽  
S. Calvert ◽  
J. Chirnside ◽  
L. Deans ◽  
...  
Keyword(s):  
Birth Interval ◽  
Pain Threshold ◽  
Endogenous Opioids ◽  
Environmental Disturbance ◽  
Opioid Activity ◽  
Oxytocin Release ◽  
Naloxone Treatment

Endogenous opioids are known to inhibit oxytocin release from the neurohypopysis (Bicknell et al, 1982). This mechanism has been suggested to be involved in the timing of parturition and delivery of young (Leng et al, 1985). Environmental disturbance in the rat (Leng et al, 1988) and pig (Lawrence et al, 1992) during parturition resulted in a naloxone reversible increase in birth interval, and an increase in plasma oxytocin concentration after naloxone treatment suggesting stress-induced opioid inhibition of oxytocin. Pain, which is associated with parturition, results in increased opioid activity and may be involved in the inhibition of oxytocin. Pregnancy-induced analgesia has been shown in the human (Whipple et al, 1990) and the rat (Gintzler, 1980), with the latter suggesting involvement of an opioid mechanism. This study aimed to determine whether an increase in pain threshold occurred over pregnancy and parturition in the pig and whether this was opioid-mediated.

scholarly journals Factors affecting milk ejection and removal during milking and suckling of dairy cows

2015 ◽  
Vol 46 (No. 4) ◽  
pp. 108-118 ◽  
Author(s):  
V. Tančin ◽  
R.M. Bruckmaier
Keyword(s):  
Dairy Cows ◽  
Blood Circulation ◽  
Endogenous Opioids ◽  
Milk Ejection ◽  
Factors Affecting ◽  
Oxytocin Release ◽  
Central Inhibition ◽  
Calf Removal ◽  
Milk Ejection Reflex ◽  
Central Level

The release of oxytocin and milk ejection occurrence in response to teat stimulation are crucial for fast and complete milk removal during milking or suckling. The milk ejection reflex can be disturbed at central or peripheral level under different experimental and practical conditions. The central disturbance results in the lack or insufficient ejection of the alveolar milk into the cistern due to inhibited oxytocin release from pituitary into the blood circulation. The important role in the pathophysiological regulation of the inhibited release of oxytocin is played by an opioid system. Endogenous opioids have suppressive effects on oxytocin release under the normal conditions of milk removal. However under the conditions of disturbed milk ejection their role in dairy cows was not confirmed. Other possible mechanisms involved in the central inhibition of oxytocin release are discussed. In dairy cows as compared with rats the mechanisms involved in the regulation of oxytocin release at the central level remain unclear. The central inhibition of oxytocin release has often been observed in dairy practice during milking of primiparous cows after parturition, suckling by alien calf, calf removal before milking, milking of cows in the presence of own calf, relocation and milking in an unknown milking place. If sufficient released oxytocin cannot induce the transfer of milk from alveoli to cistern, peripheral mechanisms are involved. Peripheral mechanisms are related to the increased levels of catecholamines and/or activation sympathetic nervous system at the udder level. In conclusion, the release of oxytocin and milk ejection efficiency can be very easily suppressed by many factors. The effect of milking conditions on regulation of milk ejection has to be considered. Thus the physiological requirements of dairy cows have to be respected.

Cortisol and ACTH release in dairy cows in response to machine milking after pretreatment with morphine and naloxone

2000 ◽  
Vol 67 (4) ◽  
pp. 467-474 ◽  
Author(s):  
VLADIMÍR TANČIN ◽  
DIETER SCHAMS ◽  
WOLF-DIETER KRAETZL
Keyword(s):  
Blood Plasma ◽  
Dairy Cows ◽  
Inhibitory Effect ◽  
Cortisol Concentration ◽  
Endogenous Opioids ◽  
Release Mechanism ◽  
Naloxone Administration ◽  
Brown Swiss ◽  
Machine Milking ◽  
Acth Release

The aim of the study was to examine the effect of morphine and naloxone pretreatment on cortisol and ACTH concentrations in response to machine milking in dairy cows. In the first part of the experiment, the effects of i.v. morphine doses (0, 21, 70 and 210 mg, one dose each day) 10 min before morning milking were studied in six Brown Swiss dairy cows. In the second part, four cows were treated 1 d after the control milking with 210 mg morphine at 10 min before milking and the next day with 210 mg naloxone at 15 min before milking followed by 210 mg morphine at 10 min before milking. In addition, four other cows were treated 1 d after the control milking with 210 mg naloxone at 10 min before milking. Pretreatment with morphine significantly suppressed the machine milking-induced increase of cortisol in blood plasma as compared with controls. Naloxone pretreatment overcame the inhibitory effect of morphine and elevated milking-induced cortisol concentrations. Naloxone administration alone significantly increased cortisol concentration resulting from milking as compared with controls. However, ACTH concentrations did not change in either control or treated animals, suggesting an ACTH-independent release mechanism for cortisol during milking. We conclude that the release of cortisol in response to machine milking seems to be modulated by endogenous opioids at the adrenal level and does not appear to be under the control of ACTH.

Sign in / Sign up

Export Citation Format

Share Document