Structural aspects of human cervical mucus.

Two types of fibrous structures can be demonstrated in midcycle cervical mucus: (1) long, thick fibers that vary in diameter from 0.5 to 5 mum and run parallel to each other, and (2) microfibrils that vary in diameter from 500 to 1,500 A and form bundles or networks. The spaces in such networks usually measure from 800 to 4,0000 A. The fibers are made up of the microfibrils and most likely represent the micelles that give spermatozoa their directional transport through the cervix.     

Bovine cervical mucus as a substitute of human cervical mucus

The sperm penetration test (SPT) in cervical mucus (CM) is an important test in screening for sperm-CM incompatibility. For a routine SPT, a sufficient amount of preovulatory CM is necessary, but the amount of human CM is often inadequate. We examined estrous bovine CM as a substitute for human CM in the SPT. Preovulatory human CM and estrous bovine CM were collected and stored frozen at -20 degrees C until use. After being thawed at room temperature, the two CM samples were compared as to their pH, spinnbarkeit and ferning patterns, and it was found that they are quite similar. In Kremer's method of SPT, sperm penetration distance, density and motility were similar in human and bovine CM for 12 hours, but thereafter sperm motility became much lower in bovine CM than in human CM. The results of SPT with spermatozoa from patients with oligozoospermia were quite similar in both CMs. When spermatozoa pretreated with antisperm antibody were used for SPT, sperm penetration was completely blocked in human CM, but no inhibition was seen in bovine CM. From these results, we conclude that bovine CM can be substituted for human CM for some, but not all, purposes.     

Canalization of human cervical mucus

Cervical mucus forms channels when dried under a coverslip. The aim of the present work was: 1) to prove mucus canalization both in spontaneous ovulatory cycles and during ovulation induction with gonadotropins; 2) to prove the estrogen dependence of this phenomenon; 3) to check the importance of the proteidic and electrolytic concentration on chaneling; and 4) to use this phenomenon clinically, shortening the time in which it occurs. The number and arrangement of channels vary during the cycle. The phenomenon is estrogen-dependent. The comparison between estradiol values and the number of channels during spontaneous ovulatory cycles and treatment with gonadotropins showed a linear relationship. Treatment with estradiol 17 beta-valerate and ethinyl estradiol induced channel formation in women with primary amenorrhea. Canalization and ferning disappeared after dialysis or treatment with proteolytic enzymes. It follows that the two phenomena have similar characteristics. Canalization increases daily, as does estradiol, whereas ferning maintains the same grade for a longer period, and when a grade of + + + is reached, it provides no further indications. With the use of a thermostat, canalization occurred in only a few hours. Chaneling, a more precise index, could therefore substitute for ferning, particularly when monitoring the induction of ovulation.     

Oral contraceptives and human cervical mucus lipids.

Oral contraceptives containing estrogenic and progestational components caused a consistent increase in human cervical mucus lipids during the menstrual cycle. Cyclic variations in cervical mucus lipids occur during the normal cycle. Phospholipids, free cholesterol, and triglycerides in cervical mucus increase with the use or oral contraceptives.     

The canalization of cervical mucus in the human fertility.

Canalization of cervical mucus from 31 patients at the obstetric/gynecologic clinic at the Universita Cattolica del S. Cuore in Rome, Italy has studied to determine the biochemical basis of canalization and its dependence on estrogen, to study the action on the canalization of hormones used to induce ovulation, and to correlate fern pattern and canalization. Cervical mucus was collected daily and applied to a glass slide, covered with an object cover, and allowed to dry. The typical arrangement of the dendritic crystals and the presence of channels among them were confirmed. Depending on the phase of the ovulatory cycle, the crystals differed in direction and in number. The number of channels consistently increased as estradiol levels increased during the proliferative phase. This happened in both natural and induced ovulatory cycles. The cervical mucus of patients with primary amenorrhea canalized when treated with estrogens. The channels ran parallel to each other. Yet, during the secretory phase, the number of channels fell rapidly and the channels were lined up in a crisscross fashion. This suggested that sperm penetration is dependent on the orientation of mucus crystals. Indeed in vitro studies showed that spermatozoa enter the periovulatory mucus in tightly packed files as if the mucus allowed only passage in this linear formation. The biophysical characteristics of canalization paralleled those of ferning. Moreover, like ferning, the presence of essential salts and proteins induced canalization. It is concluded that canalization can be used to accurately measure estradiol levels and thus to detect ovulation.     

Some molecular features of human cervical mucus

1) The time preservation effect of the enzymatic activities present in human cervical mucus has been studied. 2) In order to protect the enzymatic activities of the mucus from bacterial impurities, the enzymes studied were assayed in presence of NaN3. 3) The effect of an acid pH likes present in the vagina was also studied: a low pH exerts a marked inhibition on mucus enzymes. 4) the use of nonionic detergents for mucus solubilization does not produce a marked increase of the enzymatic activities studied. 5) A NADP-dependent malate dehydrogenase in peri- and post-ovulatory period has been identified. 6) The presence in mucus of at least four lactate dehydrogenase isoenzymes has been demonstrated and their absolute values determined.     

The role of acrosin in sperm penetration through human cervical mucus.

Enzymes have been implicated in facilitating cervical mucus penetration by spermatozoa. One of these enzymes in the neutral proteinase acrosin, which is associated with the sperm acrosome. To determine the validity of this hypothesis, human spermatozoa were incubated with the following acrosin inhibitors: p-aminobenzamidine (AB), N-alpha-p-tosyl-L-lysine chloromethyl ketone (TLCK), and p-nitropheyl-p'-guanidino benzoate (NPGB). An in vitro slide test system was developed which allowed inhibitor-treated and control spermatozoa to be evaluated against the same human cervical mucus sample. At inhibitor concentrations far exceeding those necessary for the inhibition of human acrosin, there was no effect on spermatozoal penetration into or through the mucus. These findings indicate that, in man, acrosin activity is neither necessary nor facilitory to sperm penetration of cervical mucus. Evidence is also presented that demonstrates the superiority of the newly developed double-interface slide test, especially for comparative purposes, over the tests currently in use.     

Crossed immunoelectrophoresis of sperm antibodies in human serum and cervical mucus.

Sperm agglutinating antibodies are purified from sera and cervical mucus of women with unexplained causes of infertility which were positive in the FD-test. Fractionation was performed by affinity-chromatography in a batch device and the sperm agglutinating activity controlled by the Franklin and Dukes test. This sperm antibody fraction was determined via crossed immunoelectrophoresis by migration into an anti-human serum containing gel. In all cases only one big peak resulted. The negative control serum and mucus samples demonstrated no precipitation peaks. By absorption studies it was shown that the sperm agglutinating antibodies in sera were IgM and in cervical mucus IgA. The concentration of IgA and IgM was determined by comparison with standard human IgA and IgM. Thus only one serum- and one cervical mucus antibody seems to be responsible for agglutination. The number of experiments, however, is still too small for general conclusions. This method is easily and quickly performed and can therefore be used as a routine method for the determination of sperm agglutinating antibodies. Its application for sperm-immobilizing or cytotoxic activity remains to be tested.     

Cyclic changes in the concentration of glucose and fructose in human cervical mucus.

OBJECTIVE: To determine a possible cyclic change in the concentration of glucose and fructose in the aqueous phase of human cervical mucus (CM). DESIGN: Concentrations of glucose and fructose were longitudinally determined in the aqueous phase of CM of normal cycling women using enzymatic techniques, modified for small quantities. SETTING: Patients visiting a fertility clinic were selected. PATIENTS: Nine healthy women with regular menstrual cycles of 28 +/- 3 days that appeared to be ovulatory, demonstrated by sonographic follicle immaging and serum progesterone (P) measurements. INTERVENTIONS: Cervical mucus samples were longitudinally collected preovulatory, postovulatory, and premenstrual in ovulatory cycles, monitored by ultrasound and blood estradiol and P measurements. MAIN OUTCOME MEASURES: The study was designed to measure glucose and fructose longitudinally on three different points during one cycle. RESULTS: The preovulatory glucose concentrations in CM were lower than postovulatory and premenstrual. The preovulatory fructose concentrations were lower than premenstrual. The glucose concentration correlated with the blood P level. CONCLUSION: There is a consistent change in the glucose concentration measured in human CM in three phases of the menstrual cycle. The preovulatory and premenstrual fructose concentrations differ significantly. Knowledge of the carbohydrate metabolism in human cervical mucus may contribute in illuminating the possible role of the carbohydrate metabolism in sperm migration at midcycle and implantation in the luteal phase.     

Immunoglobulins, proteinase inhibitors, albumin, and lysozyme in human cervical mucus. I. Communication: hormonal profiles and cervical mucus changes--methods and results.

The serum levels of luteinizing hormone (LH), estradiol-17beta, and progesterone were determined simultaneously with the concentrations of immunoglobulin (Ig) G, IgA, C'3, alpha1-antitrypsin, inter-alpha-trypsin inhibitor, alpha1x-antichymotrypsin, albumin, and lysozyme in cervical mucus during nine ovulatory cycles. Spinnbarkeit and ferning were also assessed, and the basal body temperature was measured and recorded during these cycles. The profiles were synchronized according to the LH peak. The midcycle period, characterized by the rapid increase and decline of estrogen and the beginning rise of progesterone, shows a prounced minimum of immunoglobulins, C'3, proteinase inhibitors, albumin, and lysozyme in cervical mucus, which is known to be most receptive to sperm penetration at this time. Although the variation of cervical mucus values is considerable during the early proliferative and the luteal phases, the midcycle values appear to be constantly low, showing slight differences among the profiles of the different parameters. The statistical evaluation and the assessment of the significance of parameters for ovulation detection and the assessment of the fertile period as well as the correlation of these parameters with basal body temperature will be the subject of the second communication of this series.     

Human cervical mucus. V. Oral contraceptives and mucus rheologic properties.

Mucus viscoelasticity on individual samples obtained from patients using combination oral contraceptives was quantitated by microrheometry. These results, in conjunction with mucus chemical characterization, indicate that combination oral contraceptive use eliminates the cyclic variations in mucus chemical, physicochemical, and rheologic properties associated with the ovulatory menstrual cycle. A correlation was demonstrated between the mucus elastic modulus and mucus nondialyzable dry weight, and the mucins produced during oral contraceptive therapy were shown to be similar to those recovered from ovulatory donors. Differences in mucus properties were noted when donors using estrogenic contraceptives were contrasted with those using androgenic contraceptives. On the basis of established relationships between sperm penetrability and mucus solids content, it was concluded that the use of contraceptives, as examined in this study, provided a secondary degree of fertility control at the cervical level.     

Interaction between human cervical mucus and sperm surface antibodies

The immunobead test was used to study the immunoglobulin class of antibodies on sperm before and after penetration through a microcolumn of cervical mucus. Sixteen men with positive sperm antibodies (positive sperm immobilization test) and sperm that penetrated cervical mucus in prior tests were selected for study. However, at the time of study, sperm from seven subjects could not be recovered from the microcolumn. The nine subjects from whom motile sperm were obtained after passage through the column had better sperm mucus penetration tests, lower proportions of sperm binding to anti-IgA immunobeads, and higher proportions of sperm with tail-tip-only binding. Sperm recovered after penetration through the mucus microcolumn displayed a greatly reduced binding to anti-IgA immunobeads in all nine subjects, whereas similar reductions in anti-IgG binding occurred only in four subjects. These results confirm that IgA and sperm-head-directed antibodies are more important than IgG and sperm tail-tip-directed antibodies in impairing sperm penetration of cervical mucus.     

Comparison of the in vitro sperm penetration test using human cervical mucus and bovine estrus cervical mucus with the postcoital test

The objective of this study was to determine how well bovine estrus cervical mucus could be substituted for human cervical mucus in the in vitro sperm penetration test (SPT) and how well the SPT compares with the postcoital test (PCT). The subjects were couples chosen at random from our infertility clinic population. The complete infertility evaluation of these couples included a PCT performed at the time of anticipated ovulation. Human cervical mucus quality was assessed using a scoring system which evaluated amount, spinnbarkeit, ferning, viscosity, and cellularity. SPT's were performed in flat capillary tubes filled with cervical mucus and exposed to semen samples for 90 minutes. Thirty-five couples had SPT's performed with wife's mucus and bovine mucus. Test results showed that PCT results correlated significantly with the SPT (P 0.02) but r was low (r = 0.37). The cervical mucus score correlated well with the SPT (P 0.001, r = 0.52) but less well with the PCT (P 0.03, r = .30). It is concluded that the SPT performed with either wife's mucus or bovine mucus is not an adequate substitute for the PCT but provides complementary information.