Ines Moretti-Rojas

Relationship of epididymal sperm antibodies to their in vitro fertilization capacity in men with congenital absence of the vas deferens

Objectives To test, using the immunobead binding technique, for the presence of antisperm antibodies on epididymal sperm, in epididymal fluid, and in serum of men with congenital absence of the vas deferens. To evaluate the in vitro fertilization (IVF) capacity of human epididymal sperm in the presence of antisperm antibodies. Design Prospective. At the time of oocyte insemination, sperm from the proximal caput epididymis or vasa efferentia were tested by direct immunobinding technique. The epididymal fluid and serum were tested by indirect immunobinding technique. Setting Center for Reproductive Health, University of California-Irvine. Patients Forty-five patients with congenital absence of the vas deferens participating in the microsurgical epididymal sperm aspiration and IVF program. Main Outcome Measure Incidence of antisperm antibodies to epididymal sperm and their relationship with IVF results. Results Sixteen men (35%) tested positively to the direct immunobead test on epididymal sperm; 7 (16%) were positive in epididymal fluid and 13 (29%) were positive in serum. Five pregnancies (31%) occurred in the positive group of which two were from patients who had sperm binding of 100% for immunoglobulin (Ig)G (all over sperm surface) and 90% (midpiece, tail) and 50% (tail, tiptail), respectively, for IgA. Five pregnancies (18%) were obtained in the negative group. No statistical difference was observed in the overall fertilization rate between the two groups. Conclusion Human epididymal sperm and epididymal fluid retrieved from men with congenital absence of the vas deferens can react positively to immunobead test. However, the presence of antisperm antibodies do not seem to impair the IVF capacity of epididymal sperm.

Low incidence of sperm antibodies in men with congenital absence of the vas deferens

The incidence of antisperm antibodies in serum and seminal fluid of 27 azoospermic men with congenital absence of the vas deferens is evaluated. The presence of antisperm antibodies was assessed using the immunobead test, the agglutination test, and immobilization test. Five patients with vasovasostomy or vasoepididymostomy attempts were included in the study and tested for the presence of antisperm antibodies. Contrary to a previous report, a low incidence (11%) of antisperm antibodies has been found in patients with congenital absence of the vas. In agreement with previous studies, in five patients who had failed vasoepididymostomy or vasovasostomy, a high incidence (71%) of antisperm antibodies was found.

Intrauterine inseminations with washed human spermatozoa does not induce formation of antisperm antibodies

In this study we investigated the possible development of serum antisperm antibodies in women receiving repeated IUI. Patients acted as its own control and were evaluated before and after various (1 to 15) IUI cycles using three different assays for antisperm antibodies. It was found that only 2 out of 41 women developed antisperm antibodies. We concluded that exposure of the upper reproductive tract to washed spermatozoa during repeated IUI with partners sperm does not significantly stimulate the appearance of serum antisperm antibodies.

Regulation of gonadotropin-stimulable adenylyl cyclase of the primate corpus luteum☆

In an effort to understand the molecular mechanisms that control luteal function in the human and nonhuman primates, we have investigated the experimental conditions for expression of gonadotropin-induced adenylyl cyclase (AC) in membrane particles from primate corpus luteum (CL) and some of the factors modulating the enzyme activity. We also examined the usefulness of the cell-free model for studying the role of AC in the regulation of CL functions in human and nonhuman primates. Enzyme activity was dependent on guanine nucleotide and Mg ion. Dose-response curves showed that the AC activation constants for hCG was about 0.1 microgram/ml. This value did not shift after the addition of guanine nucleotide. Enzyme responsiveness to prostaglandin E2 was small and, in contrast to a number of other nonprimate species, AC from the human CL was not stimulated by catecholamines. Calcium directly inhibited responsiveness of hCG-sensitive AC; inhibition was significant at 0.5 mM CaCl2 (in the presence of 1 mM EDTA and 2 mM ATP), being 90% at 2.5 mM CaCl2. These results support the concept that Ca2+ might play a role in the regulation of gonadotropin action and life span of human CL. Changes in AC activities during luteal phase and pregnancy were similar in the CL of monkeys and humans. Thus, in both cases, maximal gonadotropin responsiveness was observed during the midluteal phase. Also, during pregnancy (term and early pregnancies), responsiveness to exogenous hCG in vitro was very low, but the enzyme was readily responsive to NaF (10 mM) and forskolin (100 microM). These activities suggest that the tissue remains functionally active during pregnancy. It is concluded that the cell-free AC system is an effective model to study the cellular mechanisms that regulate luteal function in human and nonhuman primates.

The role of the adenylyl cydase system in the regulation of corpus luteum function in the human and in nonhuman primates

We have reviewed the properties of luteinizing hormone/human chorionic gonadotropic (LH/hCG)-sensitive adenylyl cyclase (AC) of human corpus luteum (CL) and its regulation by several hormones and nonhormonal activators. We have also described the changes in enzyme activity in membrane preparations of human and cynomolgus monkey CL obtained at various stages of the menstrual cycle and pregnancy. The data have been analyzed with respect to the functional status of the luteal tissue and to the species differences among primate CL. In the menstrual cycle, luteal AC responsiveness to LH/hCG was detectable during the midluteal phase, but not during the late luteal phase or in the follicular phase of the following cycle. In addition, nonhormonal stimulation was high in CL obtained during the midluteal and late luteal phases, but declined drastically by the follicular phase of the next cycle. In early pregnancy, the enzyme was unresponsive to LH/hCG stimulation, yet its sensitivity to nonhormonal stimulation was similar, if not identical, to that of midluteal phase CL. Functional activity was also evident at the end of pregnancy. These results demonstrate that expression of AC activity in primate luteal membrane changes significantly with varying hormonal status under physiologic conditions. It is concluded that the AC system in luteal membranes is an effective model to study the mechanisms that regulate function and life span of the human and nonhuman primate CL.