THE EFFECTS OF SERUM ON SPERMATOZOA

Selectivity in the transport of spermatozoa to oviductal reservoirs in the menstruating fruit bat, Carollia perspicillata

To better document the timing of ovulation and fertilization, female reproductive tracts were collected every 12 h from captive-bred fruit bats (Carollia perspicillata) on days 1–3 postcoitum and examined histologically. This also permitted observations on sperm transport, storage, and disposition. As the animals had previously been sexually segregated, most had been cycling and possessed menstrual uteri at the time of collection. Menstruation is periovulatory in this species. A widespread, headfirst orientation of spermatozoa to the uterine mucosa was observed in specimens apparently collected soon after insemination. Thereafter, however, this relationship was limited in most cases to the area around the entrance of each uterotubal junction (UTJ). A small number of spermatozoa also colonized the UTJs, which functioned as temporary sperm reservoirs on days 1–2. AlthoughC. perspicillatais monovular, no consistent differences were observed between the two oviducts in the pattern of sperm storage and release. Very few sperm were ever observed in the isthmus or ampulla (the site of fertilization). Menstrual debris (including fine particulate matter) and leukocytes present in the uterine cavity in most tracts did not gain access to the UTJ with the spermatozoa. Smooth muscle and abundant elastic fibers in the wall of the intramural UTJ, as well as receptors on its luminal epithelial cells, may play roles in the selective transport of spermatozoa to the fertilization site. While some spermatozoa are phagocytosed in the uterine lumen or by epithelial cells in the UTJ, the fate of most is probably expulsion into the vagina.

Identification and expression of boar sperm proteins in the reproductive tract that interact with antibodies in serum from an infertile woman

Serum designated as IS obtained from a young healthy infertile woman induced a head-to-head agglutination of ejaculated boar sperm. The immunoglobulin G (IgG) prepared from IS localized to the acrosomal region of the sperm head obtained from the corpus and cauda epididymis as determined by an indirect immunofluorescent method. The IgG interacted with a boar sperm protein with an estimated molecular weight of 45-kDa, determined by sodium dodecyl sulfate-polyacrylamide gel electrophoretic (SDS-PAGE) immunoblotting technique. However, the IgG did not interact with proteins extracted from sperm obtained from the testis and caput epididymis or from non-gonadal tissues including liver, kidney, spleen, muscle and serum. The IgG interacted with additional proteins of about 75- and 38-kDa present in the corpus and cauda epididymal fluids but not those in the caput epididymal fluid. The staining intensity of the 75-kDa band was reduced and that of the 38-kDa was nullified with ejaculated seminal plasma proteins. The interacting proteins were adsorbed when chromatographed on Concanavalin A Sepharose column, suggesting that they are glycoproteins.

How should sperm antibody tests be used clinically?

Immunoglobulin-specific assays are currently available for detection of patients with antibody-mediated infertility. Care must be taken in insuring that the correct immunoglobulin class is assayed, the assay is directed to the possible interaction of antibodies and sperm in the male or female genital tract, and the antigen employed will not detect antibodies against antigens not found on the plasma membrane of living sperm.

Effect of serum sources and colostral whey on bovine semen quality and spermatozoa immunoglobulin G immunofluorescence

Heifer, bull, fetal calf sera, and colostral whey were used to evaluate the influence of protein concentrations on percent progressive motility, head-to-head agglutination, acrosomal integrity, and immunoglobulin G immunofluorescence of bovine spermatozoa using ejaculates from 10 bulls. In the first experiment, 10% (vol/vol) addition of undiluted colostral whey resulted in the highest head-to-head agglutination, acrosomal integrity, and immunoglobulin G immunofluorescence. Ten percent (vol/vol) addition of whey diluted to a protein concentration equivalent to fetal calf serum produced significantly lower agglutination, acrosomal integrity, and immunoglobulin G immunofluorescence. Fetal calf serum was unable to produce agglutination and immunoglobulin G immunofluorescence of bovine spermatozoa. Heifer and bull sera produced similar responses for all seminal measurements. In Experiment 2, unheated whey and heifer serum resulted in higher response for all variables than heat inactivated whey and heifer serum. Whey treatment produced greater spermatozoal motility, agglutination, acrosomal integrity; and immunoglobulin G immunofluorescence than treatment with heifer serum. Spermatozoal immunofluorescence indicated antibodies in normal whey, bull, and heifer serum bound to spermatozoal membranes at the acrosomal region. Colostral whey was an effective source of agglutinin factor. Normal unheated whey and heifer serum did not cause sperm damage or immobilization.

Failure to identify HLA ABC and Dr antigens on human sperm

An indirect radiolabeled antiglobulin assay (IRAA), adsorption procedures, and an indirect immunofluorescent assay using cytofluorometry (IFAA) failed to identify HLA ABC or D/Dr antigens associated with untreated human sperm or human sperm exposed to capacitating conditions. Two monoclonal clones against HLA ABC and two clones against Dr antigens were utilized. Test results in the IRAA were not different regardless of whether sperm from fertile men or human red blood cells were employed in the IRAA. However, there were highly significant differences in the IRAA between the HLA antigen expression of human sperm and leukocytes. If the antihuman HLA monoclonal antibody was preadsorbed with 25 X 10(6) sperm, there was no diminution in the ability of the adsorbed antibody to identify HLA antigens on leukocytes; however, preadsorption with 2.5 X 10(6) leukocytes reduced the activity of the monoclonal antihuman HLA antibody to levels equivalent to background activity.

Complement fixing activities of normal mammalian sera for homologous and heterologous sperm

The species of the natural anti-sperm antibodies found in normal mammals have been assessed using complement fixation tests. Heated rabbit sera showed complement fixing activity with both rabbit and guinea pig sperm, indicating that rabbit natural anti-sperm antibodies do not show clear cut species specificity in these interactions. On average, rabbit sera reacted more strongly with rabbit sperm that with guinea pig sperm but the difference fell short of statistical significance (P < 0.05) and there was considerable variation between sera in their anti-sperm activities. There were, however, clear species differences between rabbit and guinea pig sera in that heated guinea pig sera showed significantly weaker anti-sperm activity than heated rabbit sera (P < 0.005). Mouse vas sperm showed greater complement fixing activities (in combination with mouse serum) than did epididymal sperm (P = 0.05). These results are discussed in relation to possible functions of natural anti-sperm antibodies.