Two plasminogen activators, streptokinase and urokinase, stimulate human sperm motility

Clinical Efficacy of Prodom-Assisted Urokinase in the Treatment of Male Infertility Caused by Impaired Semen Liquefaction

PURPOSE

To evaluate the clinical efficacy of prodom in the administration of urokinase in the vagina in couples with impaired semen liquefaction.

MATERIALS AND METHODS

Overall, 261 patients with impaired semen liquefaction were randomly divided into prodom-assisted urokinase treatment (PAUT) group (n = 91), syringe-assisted urokinase treatment (SAUT) group (n = 86), and traditional treatment (TT) group (n = 84) in the first stage. If the first stage of treatment failed, other treatment methods were initiated instead and the patients were grouped according to the newer treatment method in the second stage. The pregnancy rate, time-to-conception, and treatment costs were evaluated in each group.

RESULTS

In the first stage, the pregnancy rate in the PAUT, SAUT, and TT groups was 69.23%, 29.07%, and 22.62%, respectively; the time-to-conception was 2.66 ± 1.44, 3.69 ± 2.61, and 3.86 ± 3.00 months, respectively; the treatment costs were 658.18 ± 398.40, 666.67 ± 507.50, and 680.56 ± 480.94 $, respectively. The pregnancy rate and time-to-conception were different in the PAUT group compared with those in SAUT and TT groups (all P < 0.05). However, the difference in treatment costs was not significant (P = 0.717). In the second stage, 154 nonpregnant patients were divided into nine treatment groups, and the effects of changing TT to PAUT on the pregnancy rate, time-to-conception, and treatment costs were observed to be different from those of other treatments (all P < 0.05).

CONCLUSION

Prodom-assisted urokinase can effectively treat male infertility secondary to impaired semen liquefaction.

Total urokinase-type plasminogen activator (uPA) levels in seminal plasma are associated with positive assisted reproductive technology outcomes

PURPOSE

The plasminogen/plasmin system is an important extracellular protease system whose function has been implicated in male reproductive function. However, its clinical relevance to fertility in human assisted reproduction technologies has not been systematically investigated. Here, we examined whether total and active populations of urokinase-type plasminogen activator (uPA) in human seminal plasma and spermatozoa are predictive of pregnancy outcome in couples undergoing insemination or intracytoplasmic sperm injection (ICSI).

METHODS

Seminal samples from 182 men, 5 donors, 21 patients attending the clinic for infertility screening, and 156 for assisted reproduction technology (ART) treatment (insemination and ICSI), were evaluated. Total uPA in seminal plasma and spermatozoa as well as active uPA in seminal plasma were measured by ELISA. Sperm quality parameters and fertility outcomes following insemination or ICSI were correlated with the uPA values.

RESULTS

Active uPA in seminal plasma was positively correlated to the volume of the ejaculate, total number of spermatozoa in the ejaculate, and total motility. However, these values were not prognostic of fertility outcomes. Total uPA in spermatozoa was inversely related to sperm concentration, total sperm in ejaculate, morphology, and total and progressive motility, and this measure was not related to fertility. Importantly, however, higher values of total uPA in seminal plasma were detected in cases that resulted in pregnancy compared to those that did not follow insemination and ICSI treatment.

CONCLUSIONS

Taken together, these findings lay the foundation for further understanding the mechanism by which total uPA in seminal plasma affects fertility and how this marker can be used as a predictor of ART outcomes.

Fertilization outcome could be regulated by binding of oviductal plasminogen to oocytes and by releasing of plasminogen activators during interplay between gametes

OBJECTIVE

To detect plasminogen and plasminogen activators (PA) in oviduct and oocytes and to clarify the role of the plasminogen/plasmin system on mammalian fertilization.

DESIGN

Experimental prospective study.

SETTING

Mammalian reproduction research laboratory.

ANIMAL(S)

Oviducts and ovaries from porcine and bovine females were collected at slaughterhouse. A total of 52 oviducts and 2,292 oocytes were used. Boar and bull ejaculated spermatozoa were also used.

INTERVENTION(S)

Plasminogen concentration in oviductal fluid (OF) through the cycle was measured. Immunolocalization of plasminogen and PAs in oocytes was carried out before and after fertilization. Porcine and bovine oocytes were in vitro fertilized, with plasminogen and plasmin added to the culture medium at different concentrations.

MAIN OUTCOME MEASURE(S)

Plasminogen concentration in OF. Plasminogen and PAs immunolocalization in oocytes. Penetration and monospermy rates, number of spermatozoa in the ooplasma and on the zona pellucida (ZP) after IVF.

RESULT(S)

Oviductal fluid contains about 92 μg/mL of plasminogen. The mature oocyte shows immunoreactivity toward plasminogen and toward PAs on its oolemma and ZP. After fertilization, plasminogen and PAs immunolabeling decreases in the oocyte, suggesting its conversion into plasmin. When exogenous plasminogen is added to the IVF medium, sperm entry into the oocyte is hampered, suggesting that the role of plasminogen activation during fertilization is to reduce the number of (or to select) penetrating spermatozoa.

CONCLUSION(S)

The plasminogen/plasmin system is activated during gamete interaction and regulates the sperm entry into the oocyte.

Effect of plasmin on movement characteristics of ejaculated bull spermatozoa

Proteolytic enzymes appear to have an essential role in multiple phases of mammalian fertilization. Several observations suggest that the plasminogen activator/plasmin system might also play a role in mammalian fertilization. Movement characteristics of bovine sperm incubated with different concentrations of plasmin were investigated using a computer-assisted automated semen analysis system. Sperm were incubated up to 4h in a modified Tyrode's medium (control) and 0.1, 1, 10 and 100 mU/ml of plasmin. The percentage motile sperm was significantly higher at 0 h for sperm incubated in 1, 10, and 100 mU of plasmin. Relative to sperm incubated in control medium, lateral head displacement (ALH), curvilinear velocity, beat cross frequency, path velocity and straight line velocity (VSL) of sperm treated with 100 mU of plasmin for 0 h were increased. After 2h of incubation, sperm treated with 100 mU of plasmin showed an increase in ALH, but a decrease in VSL, straightness and linearity. The effect of plasmin on most motility parameters appears to be direct since all these parameters were affected at 0 h of incubation. Our results support the notion of hyperactivation of bovine spermatozoa following incubation with different concentrations of plasmin. The present work provides additional information to further characterize motility movement of bovine sperm associated with final preparation for fertilization.

Studies on the relationship between urokinase plasminogen activator (uPA) and human sperm motility

To clarify the role of urokinase plasminogen activator (uPA) in the mechanisms of regulating sperm motility and the ability of fertilizing, we investigated the quantities and activities of uPA in human seminal plasma and on the membrane of spermatozoa. Semens were harvested from 22 infertile patients with asthenospermia and 20 healthy fertile men according to WHO standards. To quantify the membrane-bound uPA in the samples, polyclonal antibodies against human urokinase were employed by means of a sandwich ELISA. The uPA activities in seminal plasma and on the surface of spermatozoa were determined using A-garose-Fibrine-Plate method and the experiment of immunological identification with polyclonal antibodies against urokinase. In lysates of spermatozoa, significantly lower levels of uPA (23.1 +/- 7.35 mu/10(6) cells) and uPA activity (5.13 +/- 3.85 mu/10(6) cells) were found in patient group as compared to healthy fertile men exhibiting normospermia (29.89 +/- 9.40 mu/10(6) cells and 10.17 +/- 6.18 mu/10(6) cells). In seminal plasma, uPA activity in patient group (2134 +/- 1581.3 IU/L) was also found significantly lower than that of normal group (3365 +/- 1859.5 IU/L). Positive correlations were observed between sperm motility and uPA quantities (r = 0.48, P < 0.005), as well as with uPA activities (r = 0.45, P < 0.005). Thus, it is inferred that membrane associated uPA on human spermatozoa may be related directly to sperm motility and fertility.

Complexes of tissue kallikrein with protein C inhibitor in human semen and urine

An ELISA was developed for quantifying the complex between tissue kallikrein (tKK) and protein C inhibitor (PCI) (tKK:PCI) in seminal plasma and urine. The ELISA used purified tKK:PCI complex as a standard and was specific for this complex with a detection limit of about 1.1 pM. Purified tKK:PCI complex was obtained from human urine and was 95% homogeneous as judged by SDS/PAGE. The 90-kDa band corresponding to the purified tKK:PCI complex reacted with anti-tKK and anti-PCI antibodies as judged by immunoblotting. Seminal plasma collected in the absence of extrinsic inhibitors contained 1.8 +/- 0.6 nM tKK:PCI complex and 4.7 +/- 2.8 nM immunoreactive tKK (mean +/- SD, n = 10), which indicates that about 28% of the total tKK immunoreactivity is forming complexes with PCI. When semen was collected in the presence of tKK inhibitors it had only about 6% of the tKK complexed to PCI. In vitro studies showed that the tKK:PCI complex formation in semen was accomplished in about 1 h and that heparin stimulated both the rate and the extent of complexation of tKK with PCI. Native urine showed low levels of tKK:PCI complex, but after dialysis urine had 0.17 +/- 0.05 nM complex. Formation of tKK:PCI complex in urine and semen was also demonstrated by immunoblotting. These results suggest that PCI is a physiological inhibitor of tKK and provide additional evidence of the involvement of PCI in human reproduction.

Tissue-type plasminogen activator level is decreased in human seminal plasma with abnormal liquefaction

OBJECTIVE

To determine plasminogen activators (PAs) and PA inhibitor levels in seminal plasma of patients attending an infertility clinic.

DESIGN

Quantification by immunologic method of PAs in seminal plasma.

SETTING

Patients of Department of Urology and Andrology, University Hospital, Nimes, France.

PATIENTS

Ninety-two men attending for assessment because of infertility.

INTERVENTIONS

Semen were collected by masturbation. Usual sperm parameters were determined; immediately after liquefaction, samples were snap-frozen at -85 degrees C until used for immunologic determination.

MAIN OUTCOME MEASURES

Tissue-type PA antigen, urokinase-type PA antigen, and type 1 PA inhibitor antigen levels in seminal plasma.

RESULTS

Median values of PA were 270 ng/mL (tissue-type PA) and 5.4 ng/mL (urokinase-type PA) in normozoospermia; 290 ng/mL (tissue-type PA) and 5.7 ng/mL (urokinase-type PA) in oligozoospermia; 325 ng/mL (tissue-type PA) and 3.5 ng/mL (urokinase-type PA) in oligoasthenozoospermia. Type 1 PA inhibitor antigen levels were often under detection limit. Tissue-type PA was 173.5 ng/mL in semen with abnormal liquefaction and 290 ng/mL in semen with normal liquefaction.

CONCLUSION

The study confirmed the presence of both types of PAs in seminal plasma, tissue-type PA being largely predominant. No difference was found in tissue-type PA, urokinase-type PA, or type 1 PA inhibitor antigen levels between normal and oligozoospermic semen nor between normal and asthenozoospermic semen. On the other hand, semen with abnormal liquefaction had significantly lower tissue-type PA level than normal semen.

Plasminogen activator activity and fertilizing ability of human spermatozoa

Mature spermatozoa contain a number of proteases that are supposed to contribute to their fertilizing ability. The present study was directed at plasminogen activator (PA), a protease that belongs to the group of serine proteases and converts the zymogen plasminogen to the active broad-spectrum protease plasmin. To investigate the possible role of PA in the fertilization process, we have measured sperm-bound PA activity in 63 patients included in an in-vitro fertilization (IVF) programme and assessed their relationship to standard semen parameters and the rate of fertilization. PA activity was correlated significantly with the sperm count, as well as with sperm motility and morphology. Using logistic regression analysis, specific PA (pmol pNA 10(-6) cells min-2) was found to significantly influence the probability of fertilization. Other significantly predictive factors were motility and the percentage of spermatozoa with normal morphology. The sperm concentration (10(6) cells ml-1) did not significantly affect the outcome of IVF. We suggest that sperm-bound PA is involved in the fertilization process and may represent a potential indicator of sperm fertilizing capacity.

Fibrinolytic parameters in spermatozoas and seminal plasma

Urokinase-type (u-PA) and tissue-type plasminogen activator antigen (t-PA) as well as plasminogen activator-inhibitor activity were determined in seminal plasma and lysates of the respective spermatozoas in 67 ejaculate of males in infertile marriage without genito urinary pathology. U-PA was determined by a competition RIA, t-PA by an ELISA and PAI by a spectrophotometric assay. 15 patients showed normozoospermia, 11 azoospermia and 41 oligoasthenoteratozoospermia (OAT-syndrome). In lysates of spermatozoas, significantly higher levels of both plasminogenactivators and PAI were found in patients with OAT syndrome as compared to those exhibiting normozoospermia. Whereas PAI was absent in the seminal plasma of normozoospermic ejaculate, patients with azoospermia (180 +/- 13 mU/ml.) and OAT-syndrome (60 +/- 5 mU/ml.) showed high PAI levels. The similarly high values of t-PA (190.8-227.8 ng./ml.) and u-PA (19.4-32 ng./ml.) in the same compartment confirm their predominantly prostatic origin and seem to have no influence on the quality of the ejaculate.

Determination of tissue plasminogen activator (t-PA) antigen in seminal plasma by modified enzyme-linked immunosorbant assay (ELISA)

The determination of tissue plasminogen activator (t-PA) antigen in semen by a new immunoenzymatic method was done in 152 men without genito urinary pathology. The seminal value is one hundred higher than the blood value with a log normal distribution. These levels are not influenced by freezing temperature, by the sequences freezing-thawing, by centrifugation. From split ejaculates a correlation has been established between t-PA antigen and zinc and not with fructose. These results indicate the major prostatic origin of the t-PA antigen.

Measurement of testosterone in seminal plasma, saliva and serum by solid-phase enzymeimmunoassay

When testosterone concentrations in serum, saliva and seminal plasma were measured with a solid-phase enzymeimmunoassay in which antitestosterone antibody was bound to CNBr-Sepharose-4B, we found the ratios of testosterone in saliva and seminal plasma to that in serum were 2.5 +/- 0.2% and 5.19 +/- 0.42%. Testosterone level in saliva could be an index of free serum testosterone. In addition, we found a correlation between sperm motility and testosterone level in seminal plasma when sperm motility was measured with a transmembrane migration method. This enzymeimmunoassay could be applied to clinical studies of testosterone.