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At least 19 recordsLinked to original sources

Lectin histochemistry of fallopian tube epithelial cells. Relation to ovum transport and ovum pickup.

OBJECTIVE: Data on histochemical and biochemical characteristics of the human oviduct are scarce. The exact mechanisms of ovum transport and pickup are not fully understood. STUDY DESIGN: Human fallopian tubes were obtained and prepared for histochemistry. We analyzed the distribution of negatively charged groups on the oviduct epithelium and cumulus cells and examined the distribution of glycoconjugates by means of lectin histochemistry. We tested the possible influence of poly-L-lysine and considered ABO blood group expression since these characteristics are determined by specific terminal sugar residues. RESULTS: A negatively charged glycocalyx exists on tubal epithelial cells and cumulus cells. Adherence by affinities similar to sugar-lectin binding forces could be disproven in case of commonly used lectins. Poly-L-lysine inhibited the cationic binding reaction but did not influence lectin binding. The blood group A glycoprotein presents terminal D-N-acetyl-galactosamine residues, which are demonstrated by HPA lectin binding. CONCLUSION: Our study indicates that it is unlikely that electrostatic interactions play a major role in ovum transport or pickup. Since poly-L-lysine has been described as inhibiting ovum transport, sugar-lectin binding affinities seem not to operate in ovum transport or pickup.

ABO Blood-Group System↗

The effects of tubal ligation on ovum transport in rabbits.

Ovum transport was studied in rabbit oviducts ligated 18 hr after mating in untreated and oestrogen-treated rabbits. Essentially all ova (93.5%) were recovered from the sham-ligated oviducts averaged 46.7%. Recovery of ova in oviducts ligated at the infundibulum and at the uterotubal junction was 100%. It is likely, therefore, that ova were transported prematurely into the uterus from ligated oviducts. Ovum transport through sham-ligated oviducts was significantly retarded by a single injection of oestradiol cyclopentylpropionate (25 or 250 mug) but remained accelerated in ligated oviducts diminished by 60 hr p.c. in untreated rabbits, but was maintained in oestrogen-treated rabbits. Ovum transport through distended oviducts may be accelerated by the passage of oviducal fluid into the uterus.

Animals↗

Intraoviductal administration of ribonucleic acid from estrogen-treated rats mimics the effect of estrogen on ovum transport.

In order to determine whether or not ovum transport acceleration induced by estradiol (E2) requires RNA and protein synthesis in the oviduct, inhibitors of RNA and protein synthesis were injected locally in rats treated with E2. We also tested whether administration of oviductal RNA from E2-treated rats could mimic the effect of E2 on ovum transport. Rats on Day 2 of pregnancy were given a single s.c. injection of 10 microg E2 and an intraoviductal (i.o.) injection of actinomycin D, alpha-amanitin, or cycloheximide (Chx). In control groups, either the steroid or the inhibitor or both were replaced by the respective vehicle. RNA obtained from oviduct or ileum of E2-treated rats or from the oviduct of propylene glycol-treated rats was injected into the oviducts of recipient rats on Day 1 of pregnancy. Animals were autopsied 24 h later to determine the number and distribution of eggs in the genital tract. All three inhibitors partially blocked the E2-induced ovum transport acceleration, whereas administration of inhibitors alone did not affect oviductal egg recovery. Only oviductal RNA obtained from E2-treated rats decreased the number of oviductal eggs (active extract). To interpret this finding, the active extract was preincubated with RNase or DNase before i.o. administration. Other groups of recipient rats also treated with active extract were injected s.c. with Chx, or their uterine horns were ligated to disclose the fate of the missing oviductal eggs. Active extract treated with RNase did not decrease the number of oviductal eggs; Chx blocked the effect of the active extract; and eggs missing from the oviduct were partially recovered in the uteri of ligated recipient rats. It is concluded that protein synthesis in the oviduct is required for the full effect of E2 on ovum transport and that one or more RNA species induced by E2 in the oviduct are by themselves able to mimic, and therefore mediate, the effect of E2 on ovum transport.

Amanitins↗

Pharmacologic modification of the time course of ovum transport in guinea pigs.

Various agents were examined for their effects on ovum transport in the guinea pig. Estrogen significantly accelerated ovum transport in this species. The experiments further demonstrated that estrogen did not act by inducing prostaglandin synthesis, nor by altering plasma progesterone levels. The estrogen-induced acceleration was significantly antagonized by tamoxifen, an antiestrogen that acts by interfering with estrogen receptor synthesis. Cycloheximide also antagonized the effects of estrogen on ovum transport. These data suggest that the modification of ovum transport by estrogen is due to the entrance of estrogen into the nuclei of target cells, and subsequent protein synthesis. Although we assume that this action occurs at the level of the oviduct, our experiments do not prove this assumption.

Animals↗

Effects of passive immunization against estradiol on rabbit ovum transport.

The role played by estradiol in control of ovum transport was studied in rabbits that were induced to ovulate by hCG stimulation. Withholding estrogen from target tissues during ovum transport by passive immunization with sheep anti-estradiol immunoglobulin (AE) resulted in accelerated oviductal transport and expulsion of ova from the uterus. The degree of accelerated transport was dependent on the duration of AE treatment. When AE treatment was started 24 h before hCG, fewer ova were recovered from the reproductive tracts at 72 h after hCG than were recovered from tracts of animals treated with a nonspecific immunoglobulin; the location of ova at 48 h after hCG was unaltered by this AE regimen. When AE treatment was started 72 h before hCG, fewer ova remained in the oviducts than were found in the tubes of controls at 48 h after hCG; and at 48 h after hCG, ova were found in the uteri of animals that had been treated with AE starting 72 h before hCG. When AE treatment was started 48 h before hCG, the position of eggs within the reproductive tract was not different from controls at 48 h after hCG. These observations support the concept that estrogen withdrawal is involved in the transport of ova through the oviduct of the rabbit, and suggest that the lack of estrogen secretion from the time of ovulation through the transport period is important in the control of normal ovum transport.

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Effect of lysophosphatidic acid on the ovum transport in mouse oviducts.

The effects of lysophosphatidic acid (LPA) on ovum transport in mouse oviducts were studied. When excised oviducts were incubated at 37 degrees C under 5% CO2 in humidified air for 24 hours, addition of LPA at 10 microM to the medium significantly accelerated the rate of ovum transport, and 1 microM LPA slightly increased the ovum transport rate. These increases were not inhibited by 10 microM indomethacin, a cyclooxygense inhibitor, but were suppressed by 260 ng/ml of pertussis toxin or 10 microM verapamil, a voltage-sensitive calcium channel blocker. These data suggested that LPA stimulates mouse ovum transport by contracting oviductual smooth muscle via a voltage-sensitive calcium channel mediated by a pertussis toxin-sensitive G-protein-linked receptor.

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A model of ovum transport.

A theoretical fluid dynamical model of ovum transport in the oviduct incorporating transport mechanisms due to ciliary activity, muscular activity and an applied pressure drop across the oviduct is developed. Theory suggests that the cilia provide the steady component of ovum transport whereas muscular activity results in highly oscillatory motion. If muscular activity is to provide transport in a pro-uterine direction, a coordinated sequence of muscular activity with a strong pro-uterine bias is needed. Changes in pressure are highest in the narrowest sections. The highly convoluted rugae may allow "leakback" around the ovum so relieving the pressure drop across the ovum in narrower sections of the oviduct.

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Time course of ovum transport in guinea pigs.

The time course of ovum transport was determined in cycling guinea pigs. The occurrence of ovulation was determined in assessing changes in vaginal cytology. The day of the postovulatory leukocyte influx was considered day 1 of the cycle. Ovum transport in guinea pigs is characterized by a relatively long sojourn in the ampulla, followed by rapid transport through the isthmus. This pattern is similar to that seen in women and subhuman primates and different from the pattern in rabbits.

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The autonomic nervous system and its relationship to tubal ovum transport--a reappraisal.

The role of the autonomic nervous system in controlling ovum transport remains obscure. Although not studied extensively in the oviduct, the para-sympathetic nervous system does not appear to significantly influence ovum transport. The sympathetic nervous system of the oviduct and its pharmacology have been studied more thoroughly. Despite this, little information is available concerning cellular mechanisims of adrenergically altered motility or transport. In spite of much speculation, the weight of evidence suggests that, at least in the rabbit, the sympathetic nervous system plays a minor role in the control of ovum transport.

Animals↗

Fertility and ovum transport after microsurgical removal of the uterotubal junction in rabbits.

The role of the uterotubal junction (UTJ) in fertility and ovum transport was investigated following unilateral microsurgical resection of the UTJ in 15 rabbits. Fourteen animals became pregnant on the UTJ resected side and 14 on the control side following artificial insemination and induction of ovulation. Fifty-two of 61 ova (85.2%) became implanted on the control side, and 56 of 68 ova (82.3%) became implanted on the resected side. Ten days after delivery, artificial insemination and induction of ovulation were repeated. Ovum transport was examined at 60, 66, and 72 hours. There was no significant difference in ovum transport between UTJ resected and control sides. The distribution of ova within the oviduct and the time of their entrance into the uterus was comparable in both sides. These results indicate that the UTJ is not necessary for normal fertility and ovum transport in the rabbit.

Animals↗

Temporal relationships critical to progesterone-induced acceleration of ovum transport.

Previous investigators have demonstrated that 2.5 mg fo progesterone, administered intramuscularly to rabbits on the day of ovulation and the 2 preceding days (Days -2, -1, and 0) significantly and consistently accelerates ovum transport. In contrast, when given on the day of ovulation and the 2 following days (Days 0, +1, and +2), progesterone does not accelerate ovum transport. The experiments reported were designed to define more precisely the temporal relationships critical to progesterone-induced acceleration of tubal ovum transport. Our observations suggest 3 important conclusions: 1) Progesterone, when given at least 1 day, and not more than 2 days, prior to ovulation does induce accelerated ovum transport. 2) The progesterone responsive mechanism is dose dependent. 3) The acceleration is partially antagonized if progesterone treatment is begun 3 days prior to ovulation.

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Effect of 15(S)-15-methyl prostaglandin F2alpha on human oviductal motility and ovum transport.

The effects of an intravenous infusion of 15(S)-15-methyl prostaglandin F2alpha (PGF2alpha) on oviductal motility and ovum transport were studied in women who were scheduled for elective tubal sterilization. Infusion rates of 0.38 microgram/kg/hour or higher caused an increase in oviductal motility in all patients. Lower infusion rates did not always cause a stimulation of motility. Low infusion rates generally caused an increase in the amplitude of contractions without any effect on basal oviductal tone. The higher infusion rates usually caused a large increase in basal tone as well as an increase in the amplitude of contractions. Ova were recovered from the oviducts of five patients who had received an intravenous infusion of 15(S)-15methyl PGF2alpha. The ova were recovered from the ampulla in three patients, from the ampullary-isthmic junction in one patient, and from the isthmus in one patient. Since one would expect to recover ova from the oviducts at similar times under normal circumstances, there was no evidence that this prostaglandin treatment caused an acceleration of ovum transport. These data support the conclusion that a PGF analog which stimulates oviductal motility does not necessarily also accelerate ovum transport in women.

Fallopian Tubes↗

Ovum transport in the rat oviductal ampulla in the absence of muscle contractility.

Ovum transport in mammalian oviducts involves two main effectors: ciliary motility and muscle contractility. To study the relative contribution of cilia to ovum transport in the rat, we blocked smooth muscle activity with isoproterenol, a beta-adrenergic agonist, and measured transport rates of surrogate ova in situ. Transport rates before isoproterenol administration were 0.04 mm/s in the cephalic ampulla and 0.03 mm/s in the caudal ampulla; rates were unchanged after administration of isoproterenol. To determine if isoproterenol affected ciliary activity, we measured ciliary beat frequency with laser-scattering spectroscopy over the effective isoproterenol dosage. Isoproterenol did not cause a significant change in ciliary beat frequency. Our results show that in the rat oviductal ampulla, ciliary motion is capable of transporting ova in the absence of muscle contractility.

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Description of the structural control systems of ovum transport in the quail oviduct.

Some electron microscropic and light microscopic aspects of the quail oviduct have been studied in relation to ovum transport. Previously it has been shown that in this smooth muscle there exist spontaneous coordinated electrical and mechanical activity which suggests a good electrical and mechanical coupling of the muscle cells. The structural basis for this coupling is not known. The majority of muscle cell contacts observed were simple appositions and intermediate junctions. Less numerous were attachments of the interdigitation type. No nexuses or tight junctions were seen. Mechanical stretching or contraction of cells induced with 10(-4)M carbachol did not affect the contacts. The fine structure of the muscle cells did not differ from that described for other smooth muscles. Electronmicroscopically the muscle cell bundles could not be distinguished into separate layers, in the light microscope the cell bundles were spirally arranged. Stretching of the oviductal strips to the length to which the ovum stretches the muscular wall during ovum transport caused re-orientation of the muscle cell bundles. One-directional stretching turned the axes of the muscle cells and the collagen bundles parallel, while stretching in two direction made the tissue look like a network. The re-orientation of muscle cell bundles may be of importance in producing forces in the muscular tunic during ovum transport. The nerve supply to the muscle cells was negligible. These and previous results show that structurally the muscular wall of the quail oviduct is a dynamic unity in which the ovum via stretch induces the electrical and mechanical activity throughout the tissue. Innervation may play a minor role in controlling the contractions.

Animals↗

Smooth muscle of the quail oviduct functions as a stretch receptor during ovum transport.

The present experiments were conducted to test the hypothesis that ovum transport in the quail oviduct is regulated by a time-dependent, stretch-mediated feedback cycle which alters the frequency of contractions. According to this hypothesis, a ligature preventing the forward movement of ovum should reverse the direction of the feedback cycle and an artificial ovum should be transported like the normal ovum. When the ligature was placed in the borderline between magnum and isthmus, it caused the reversal of transport direction after a delay of several minutes. Once the direction had changed, it persisted until the ovum was expulsed through the fimbrial end or until a second reversal was caused by either a second ligature or a minor mechanical impediment at the proximal end of the magnum. The ovum was transported between the ligatures at the mean speed of 1.7 +/- 0.17 mm/min (n = 7) until the ovum broke. An artificial ovum placed in the proximal magnum from which the natural ovum had been removed, was transported like the natural ova. Myoelectrical activity recorded with suction electrodes was statistically similar in both types of experiments and the direction of the frequency gradient changed when the transport direction was reversed. The frequency of the electrical activity of oviductal smooth muscle was significantly higher behind the ovum than in its front whether ova were transported in the direction of shell gland or infundibulum; in the segment maximally stretched by the ovum the activity was significantly lower than in other segments. These observations confirmed the hypothesis and suggest that the quail oviduct functions like a stretch receptor.

Animals↗

Ovum transport after microsurgical anastomosis of the rabbit oviduct.

From experimental work in rabbits it is known that pregnancy outcome is influenced unfavorably by tubal resection anastomosis in spite of the preservation of tubal patency. In 104 Dutch belted rabbits the impact of microsurgical resection anastomoses on ovum transport during the first 24 hours after ovulation was examined. In oviducts in which the ampulla had been operated on, ovum transport was delayed. Mucosal irregularities that interfere with normal ampullary transport by cilia activity may account for the delay noted. Alterations in the duration of ovum transport in the oviduct may influence pregnancy outcome by creating an inappropriate tubal environment for the early embryo or by creating asynchrony between the embryo and the endometrium. No changes were observed in transport in oviducts in which the isthmus had been operated on: even a small segment of isthmus seems to act as a physiologic sphincter and to prevent premature ovum entrance into the uterus.

Animals↗

Effect of oestradiol delivered from a perioviducal device on ovum transport in mice.

Silastic devices impregnated with oestradiol and blank devices were placed around both oviducts and around skeletal muscle bundles in the forelegs to attain local and systematic delivery, respectively. Another group of mice received an oestradiol-impregnated device around one oviduct and a blank device in the contralateral oviduct. Implantation of blank devices around the oviducts and in the forelegs did not alter ovum transport. Devices impregnated with oestradiol placed around both oviducts produced a dose-dependent delay of ovum transport, which was more pronounced than the effect of devices located in the forelegs. Oviducts receiving an oestradiol-loaded device had a larger retention of ova than did the contralateral oviducts receiving a blank device. These results demonstrate a direct action of oestradiol upon the oviduct to delay ovum transport in the mouse.

Animals↗

Ovulation, ovum transport and implantation in the adult golden hamster.

The time of ovulation in various hamster colonies and its relationship with the period of light as reported in the literature was compared with the observations made in this study. Ovulation and transport of ova to the oviduct was studied during days 4 and 1 of the estrous cycle. Microscopical examination of the various oviducal segments for the presence of ova resulted in a detailed description of physiological ovum transport for the adult golden hamster. Simultaneously the developmental stages of ova were checked together with the occurrence of unfertilized ova and the percentage of ova implanted in the uterus. Finally, the contractility of the oviduct in vitro was observed for groups of animals at different times in the pre- and postovulatory period. The presented data indicate that the golden hamster is useful for the study of ovum transport processes. This is due to the regularity of its estrous cycle including multiple ovulations, and because ovum transport can easily be monitored microscopically with a high degree of reliability.

Animals↗