Uterine peristalsis, directing sustained and rapid sperm transport from the external cervical os or the cervical crypts to the isthmic part of the tube ipsilateral to the dominant follicle, changes in direction and frequency during the menstrual cycle, with lowest activity during menstruation and highest activity at mid cycle. It was therefore suggested that uterine peristalsis is under the control of the dominant follicle with the additional involvement of oxytocin. To test this hypothesis, vaginal sonography of uterine peristalsis was performed in the early, mid and late proliferative phases, respectively, of cycles of women treated with oestradiol valerate and with human menopausal gonadotrophin following pituitary downregulation, with clomiphene citrate and with intravenous oxytocin, respectively. Administration of oestradiol valerate resulted in oestradiol serum concentrations comparable with the normal cycle with a simulation of the normal frequency of peristaltic contractions. Elevated oestradiol concentrations and bolus injections of oxytocin resulted in a significant increase in the frequency of peristaltic contractions in the early and mid follicular phases, respectively. Chlomiphene tended, though insignificantly so, to suppress the frequency of peristaltic waves in the presence of elevated oestradiol concentrations. In the late follicular phase of the cycle extremely elevated oestradiol concentrations as well as the injection of oxytocin resulted only in an insignificant further increase of peristaltic frequency. In the normal cycles, as well as during extremely elevated oestradiol concentrations and following oxytocin administration, the peristaltic contractions were always confined to the subendometrial layer of the muscular wall. The results and the review of literature indicate that uterine peristalsis during the follicular phase of the menstrual cycle is controlled by oestradiol released from the dominant follicle with the probable involvement of oxytocin, which is presumably stimulated together with its receptor within the endometrial-subendometrial unit and therefore acting in an autocrine/paracrine fashion. Since unphysiological stimulation with oestradiol and oxytocin did not significantly increase the frequency of uterine peristalsis in the late follicular phase of the cycle it is assumed that normal preovulatory frequency of uterine peristalsis is at a level which cannot be significantly surpassed due to phenomena of refractoriness of the system.

Adult↗

PubMedDate not supplied

Sonographic evidence for the involvement of the utero-ovarian counter-current system in the ovarian control of directed uterine sperm transport.

Sperm transport from the cervix into the tube is an important uterine function within the process of reproduction. This function is exerted by uterine peristalsis and is controlled by the dominant ovarian structure via a cascade of endocrine events. The uterine peristaltic activity involves only the stratum subvasculare of the myometrium, which exhibits a predominantly circular arrangement of muscular fibres that separate at the fundal level into the fibres of the cornua and continue into the circular muscles of the respective tubes. Since spermatozoa are transported preferentially into the tube ipsilateral to the dominant follicle, this asymmetric uterine function may be controlled by the ovary via direct effects utilizing the utero-ovarian counter-current system, in addition to the systemic circulation. To test this possibility the sonographic characteristics of the uterine vascular bed were studied during different phases of the menstrual cycle. Vaginal sonography with the measurement of Doppler flow characteristics of both uterine arteries and of the arterial anastomoses of the uterine and ovarian arteries (junctional vessels) in the cornual region of both sides of the uterus during the menstrual phase of regular-cycling women demonstrated significant lower resistance indices of the junctional vessels ipsilateral to the side of the dominant ovarian structure as compared with the corresponding arteries contralaterally. By the use of the perfusion mode technique, it could be observed that vascular perfusion of the fundal myometrium was significantly increased ipsilateral to the dominant follicle during the late follicular phase of the cycle. These results show that the endocrine control of the dominant ovarian structure over uterine function is not only exerted via the systemic circulation but also directly, most probably utilizing the utero-ovarian counter-current system.

Adult↗

PubMedDate not supplied

Endometriosis: a dysfunction and disease of the archimetra.

Endometriosis is considered primarily a disease of the endometrial-subendometrial unit or archimetra. The clinical picture of endometriosis characterises this disease as a hyperactivation of genuine archimetrial functions such as proliferation, inflammatory defence and peristalsis. While the aetiology of the disease remains to be elucidated, a key event appears to consist in the local production of extraovarian oestrogen by a pathological expression of the P450 aromatase. The starting event may consist in a hyperactivity of the endometrial inflammatory defence, a hyperactivity of the endometrial oxytocin/oxytocin receptor system or in the pathological expression of the P450 aromatase system itself. Regardless of which of these levels the starting event is localized in, they influence each other on both the level of the archimetra and the endometriotic lesions. Locally elevated oestrogen levels inevitably up-regulate the endometrial oxytocin mRNA and increased levels of oxytocin result in uterine hyperperistalsis, increased transtubal seeding of endometrial tissue fragments and finally subfertility and infertility by impairment of the uterine mechanism of rapid and sustained sperm transport. Locally increased levels of oestrogen lead, on both the level of the endometrial-subendometrial unit and the endometriotic lesion, to processes of hyperproliferation. These processes result, on the level of the uterus, in an infiltrative growth of elements of the archimetra into the neometra and, on the level of the endometriotic lesion, in infiltrative endometriosis. There is circumstantial evidence that trauma might be an important initial event that induces the specific biochemical and cellular responses of the archimetra. This model is able to explain both the pleiomorphic appearance of endometriosis and the, up until now, enigmatic infertility associated with mild and moderate endometriosis.

Aromatase↗

PubMedDate not supplied

[Endocrinological studies in Reifenstein's syndrome].

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Adolescent↗