Response of the human fallopian tube to adrenergic stimulation

A Review: Biomechanical Aspects of the Fallopian Tube Relevant to its Function in Fertility

The fallopian tube (FT) plays a crucial role in the reproductive process by providing an ideal biomechanical and biochemical environment for fertilization and early embryo development. Despite its importance, the biomechanical functions of the FT that originate from its morphological aspects, and ultrastructural aspects, as well as the mechanical properties of FT, have not been studied nor used sufficiently, which limits the understanding of fertilization, mechanotrasduction, and mechanobiology during embryo development, as well as the replication of the FT in laboratory settings for infertility treatments. This paper reviews and revives valuable information on human FT reported in medical literature in the past five decades relevant to the biomechanical aspects of FT. In this review, we summarized the current state of knowledge concerning the morphological, ultrastructural aspects, and mechanical properties of the human FT. We also investigate the potential arising from a thorough consideration of the biomechanical functions and exploring often neglected mechanical aspects. Our investigation encompasses both macroscopic measurements (such as length, diameter, and thickness) and microscopic measurements (including the height of epithelial cells, the percentage of ciliated cells, cilia structure, and ciliary beat frequency). Our primary focus has been on healthy women of reproductive age. We have examined various measurement techniques, encompassing conventional metrology, 2D histological data as well as new spatial measurement techniques such as micro-CT.

Changes in mechanical properties of the circular muscle of the isthmus of the human fallopian tube in relation to hormonal domination and postovulatory time

Using the isthmic circular ring from 76 subjects, the authors investigated the in vitro mechanical response of the fallopian tube to noradrenalin and field stimulation. In the proliferative and menopausal phases, preparations with high plasma levels of estradiol showed a high contractile response. In the secretory phase, responses were inhibitory or low at 4 to 6 and 11 to 14 days after the elevation of basal body temperature and were excitatory at 0 to 3 and 7 to 10 days. The exogenous application of estradiol failed to suppress these inhibitory responses. The findings suggest that the inhibitory response at 4 to 6 days after the elevation of BBT may aid in the release of the ovum from the fallopian tube and that after the ovulation, progesterone is mainly related to the response of the circular muscle to noradrenalin.

Adrenergic responses of the various smooth muscle layers at the human uterotubal junction

The different muscle layers at the human uterotubal junction (UTJ) were mechanically separated, and 1-mm wide muscle strips were isolated and mounted in organ chambers for isometric recording of contractile activity. It was found that the adrenergic neurotransmitter noradrenalin elicited an inhibition of the spontaneous phasic activity in the inner longitudinal and the intermediate circular layers but caused a clear-cut excitatory response in the outer, spiral-shaped (uterine) layer. The excitatory response was totally blocked by treatment with phenoxybenzamine, an alpha-adrenoceptor antagonist, whereas the inhibitory effects were abolished after pretreatment with the beta-adrenoceptor antagonist propranolol. The data demonstrate a differentiated distribution of alpha- and beta-adrenoceptors in the smooth musculature at the proximal end of the tubal isthmus. It is suggested that this arrangement might serve an important purpose in the physiologic control of ovum transport in women.

The response of the human Fallopian tube to ergonovine and methyl-ergonovine in vivo

Ergonovine maleate (EM) is a powerful stimulant of human tubal motility. It has been therefore thought that EM could interfere with normal ovum transport and serve as a contraceptive. The tube activating effects of EM and methyl EM were evaluated in 14 women and results confirmed that both are powerful stimulants of the human Fallopian tube. EM immediately post coitus significantly reduces the conception rate.

Tubal and uterine motility in vivo in the rhesus monkey

Previous data indicate that there are definite qualitative and quantitative patterns of tubal activity during the various phases of the menstrual cycle. In the present investigation, the simultaneous activity of the uterus and Fallopian tube was recorded in vivo in mature rhesus monkeys throughout the menstrual cycle. The observations indicate that there are characteristic patterns of both tubal and uterine activity, depending on the various phases of the menstrual cycle. The simultaneous recordings of tubal and uterine activity show that the tubal and uterine contractions are not synchronous or even have a similar pattern. The presence of a transmetrial catheter for recording of uterine activity seems to modify the patterns of tubal activity, particularly during the ovulatory phase. It seems possible that the transmetrial catheter has a similar effect as an intrauterine contraceptive device in this species.