Motricité utérine de la Brebis, avant, pendant et après la parturition spontanée ou après traitement par la dexaméthasone

Prud'homme, Marie-Jeanne; Bosc, M. J.; Nicolle, Agnès; Lebreton, Y.; Locatelli, Anna

doi:10.1051/rnd:19770102

Cited by 15 publications

(6 citation statements)

References 6 publications

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“…In both these physiological states, the uterine electrical activity pattern, with or without the perfusion of physiological saline, corresponded to that previously described by Prud'homme and Bosc (1977), Toutain et a/. (1983) and Prud'homme and Pel6 (1984).…”

Section: Introductionsupporting

confidence: 63%

Uterine motor responses to an α-adrenergic agonist (phenylephrine) in the ewe during oestrus and at the end of gestation

Mj¹

1986

Reprod. Nutr. Dévelop.

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Summary. The a-adrenergic activity of the myometrium was studied by recording the electromyographic activity (EMG) of the uterus in 4 conscious cyclic ewes during oestrus and in 8 conscious pregnant ewes during the last 6 days of gestation.In the cyclic ewes, changes in intra-uterine pressure were recorded at the same time as the EMG. Motor responses to perfusions of phenylephrine, a specific a-adrenergic agonist, were studied at three uterine sites. In the ewes in oestrus, uterine activity was stimulated at the three sites by perfusions with phenylephrine (0.6, 2.5, 5 or 10 pg/kg/min). The whole uterine horn was a-adrenergic-responsive. The effect of the drug was dosedependent in that the uterine response increased with the dose and reached a plateau at 5 pg/kg/min.In the late pregnant ewes, the motor responses to the perfusion of phenylephrine at 10 wg/kg/min were studied at three uterine sites once a day during the last 6 days of gestation. Plasma levels of progesterone and total oestrogens were measured at the same time.Up to 48 h before parturition, the effect of phenylephrine depended on the uterine site. The drug had no or little effect at the tubal end of the horn. Phenylephrine stimulated uterine activity at the cervical end of the horn in at least 50 % of the ewes. Thus, during this part of gestation, the a-adrenergic sensitivity of the myometrium was greater at the cervical than at the tubal end of the uterine horn. Forty-eight hours before parturition, phenylephrine stimulated uterine activity at all three uterine sites in all the ewes. Thus, a-adrenergic sensitivity developed over the uterine horn beginning 48 h before parturition at the same time that the oestrogen level increased.Introduction.

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Section: Introductionsupporting

confidence: 63%

Uterine motor responses to an α-adrenergic agonist (phenylephrine) in the ewe during oestrus and at the end of gestation

Mj¹

1986

Reprod. Nutr. Dévelop.

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“…Uterine activity in sheep during pregnancy and around parturition has been extensively described (Hindson, Schofield & Turner, 1968;Naakteboren et al, 1975;Prud'homme & Bosc, 1977;Krishnamurti, Kitts, Kitts & Tompkins, 1982;Harding et al, 1982). In contrast, the possibility of motor activity of the cervix during pregnancy has not been evaluated.…”

Section: Introductionmentioning

confidence: 97%

Electrical and mechanical activity of the cervix in the ewe during pregnancy and parturition

Toutain¹,

Garcia‐Villar²,

Hanzen

et al. 1983

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Myoelectrical and mechanical activities of the uterine cervix and horns of ewes fitted with electrodes and strain gauges were measured from the 30th day before until the 3rd day after parturition. During pregnancy, cervical electromyograms presented regular episodes of strong activity of a mean duration of 7 min, termed regular spiking activity, occurring at about 50-min intervals. Between two episodes, isolated or low frequency spikes occurred randomly and constituted the irregular spiking activity. The alternation of irregular and regular spiking activities was called the myoelectrical complex of the cervix. Clear relationships were noticed between electrical and mechanical events. On the pregnant uterine horn (singleton pregnancy) or on both horns (twin pregnancy), a myoelectrical complex pattern similar to that of the cervix was recorded. Regular spiking activity on the cervix and pregnant horn(s) occurred mainly simultaneously.No significant evolution of the myoelectrical complex pattern was noted throughout the last month of pregnancy until 2\p=n-\3 days before parturition. The activity pattern was then modified according to three characteristic phases: (1) a phase of relative inhibition of the cervix and pregnant horn(s) 48 h before lambing and lasting about 17 h; (2) a phase of increasing activity occurring thereafter over the whole genital tract with an average duration of 31 h; and (3) a phase of continuous activity of the cervix and uterus for 0\ m=. \ 4\ p=n-\ 3\ m=. \ 8h which accomplished the expulsion of the lamb.It is concluded that during the last month of pregnancy the cervix is active and that its activity arises from a basic ultradian rhythm involving the entire genital tract. Furthermore, although our results do not offer an explanation for the preparturient increase of cervical compliance described by others, they definitely excluded cervical muscular inhibition during the last 24 h of pregnancy and at the time of cervical dilatation.

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“…Data concerning the motility of the genital tract of the ewe during pregnancy have been generally limited to the peripartum period (Hindson, Schofield & Turner, 1968;Hindson & Ward, 1973;Naaktgeboren et al, 1975;Prud'homme & Bosc, 1977;Krishnamurti, Kitts, Kitts & Tompkins, 1982). Motor activity episodes in the uterus of ewes have been described during the last third (Nathanielsz, Bailey, Poore, Thorburn & Harding, 1980) and the second half (Harding et al, 1982) of pregnancy.…”

Section: Introductionmentioning

confidence: 96%

Pattern of electrical activity of the ovine uterus and cervix from mating to parturition

Garcia‐Villar¹,

Toutain²,

Ruckebusch³

1984

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The electrical activity of the uterus, greater curvature and lesser curvature, and of the cervix were recorded throughout several oestrous cycles, matings and the entire course of pregnancy in a set of ewes. In cyclic ewes, all electrode sites were active during the periovulatory period, but during the luteal phase only the cervix and lesser curvature continued to present regular activity, i.e. episodes of 6-8 min duration. Matings failed to disrupt the oestrous activity pattern in 5 out of 6 ewes. During the subsequent pregnancy in 4 ewes, activity, when present, consisted of the cyclic occurrence of regular activity episodes in the gravid horn(s) (greater curvature) and in the cervix (and lesser curvature in 1 ewe). Three phases were recognized on the basis of the activity of the greater curvature of the gravid horn(s). The first phase corresponded to quiescence of the horn from Day 5 (Day 0 = mating) to about Day 41. The second phase was marked by the sudden onset of regular activity of the uterus; frequency rapidly increased and maximal values were reached around Day 49, after which frequency progressively decreased until around Day 66. The third phase was characterized by a steady state in genital tract activity until the peripartum period. The cervix and lesser curvature activity followed an almost similar development of regular activity episodes with only slight time differences.

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Motricité utérine de la Brebis, avant, pendant et après la parturition spontanée ou après traitement par la dexaméthasone

Abstract: Summary. Uterine Up to birth, bursts are increasingly regular and frequent while the amplitude of variations in intra-uterine pressure increases.Introduction.

Cited by 15 publications

References 6 publications

Uterine motor responses to an α-adrenergic agonist (phenylephrine) in the ewe during oestrus and at the end of gestation

Uterine motor responses to an α-adrenergic agonist (phenylephrine) in the ewe during oestrus and at the end of gestation

Electrical and mechanical activity of the cervix in the ewe during pregnancy and parturition

Pattern of electrical activity of the ovine uterus and cervix from mating to parturition

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