The importance of the hypoosmotic swelling test and acrosin activity assay for identifying subpopulations of idiopathic infertile men

Effects of a micronutrient supplementation combined with a phosphodiesterase type 5 inhibitor on sperm quantitative and qualitative parameters, percentage of mature spermatozoa and sperm capacity to undergo hyperactivation: A randomised controlled trial

The main objective of this study was to evaluate the effects of a micronutrient supplementation (MS) combined with avanafil on sperm function. Oligoasthenospermic men (n = 217) were treated daily for 90 days with either an MS (45 men, Group A), l-carnitine (44 men, Group B), MS plus avanafil (43 men, Group C) or avanafil (43 men, Group D); another group of 42 men with oligoasthenospermia (Group E) received no treatment. Sperm parameters were evaluated before and after the end of treatment in each Group A, B, C and D respectively. The same sperm parameters were measured in each participant of Group E before and at the 90-day experimental period. Within Groups A, C or D, the total percentage of motile spermatozoa, the hypoosmotic swelling test (HOST) result and the percentage of hyperactivated spermatozoa after incubation under conditions known to induce sperm capacitation were significantly greater after MS or MS plus avanafil treatment, or avanafil treatment than before the respective treatment. We suggest that MS or MS plus avanafil combined administration or avanafil alone improves sperm membrane permeability with an overall result improvement in sperm motility, outcome of HOST and increase in the percentage of hyperactivated spermatozoa.

Discrepancy between sperm acrosin activity and sperm morphology: significance for fertilization in vitro

BACKGROUND

In routine semen analysis, discrepancies may occur between sperm acrosin activity test results and sperm acrosomal morphology.

METHODS

Discrepant test results of sperm acrosin activity (spectrophotometric assay) vs. sperm morphology (strict criteria) in the initial diagnostic investigation of 107 infertile couples were evaluated with respect to fertilization rate (% oocytes with 2 pronuclei) further obtained in IVF treatment.

RESULTS

Acrosin activity positively correlated with sperm morphology (% normal forms) (r=0.537) and fertilization rate (r=0.526). ROC curves for the prediction of > or =50% fertilization rate were comparable for acrosin activity and sperm morphology, with optimal cutoff values at 25 microIU/10(6) sperm and 10%, respectively. In multiple regression analysis, sperm acrosin activity (P=0.002) predicted fertilization rate independently of sperm morphology (P<0.001) and sperm vitality (eosin-nigrosin stain) (P=0.03). Acrosin activities > or =25 microIU/10(6) sperm were observed in 36% of severe teratozoospermic samples (< or =4% normal spermatozoa) associated with low fertilization rate. Twenty percent of the morphologically normal ejaculates showed a low acrosin activity (<25 microIU/10(6) sperm) and low hypoosmotic swelling test (HOST) scores (31.4+/-7.6%) and were associated with low fertilization rate.

CONCLUSION

The sperm acrosin assay can help to predict sperm fertilizing capacity in IVF independently of sperm morphology.

Inhibition of sperm glutathione S-transferase leads to functional impairment due to membrane damage

The role of glutathione S-transferase (GST) in the defense mechanisms of sperm is not known. We report here interference with normal motility, acrosome reaction and fertilizing ability of the goat sperm as a consequence of inhibition of GST activity. That these functional impairments were due to membrane changes was evident from the alteration in the lipid peroxidation status of these cells after GST inhibitor treatment. Increased reactive oxygen species production by the cell which occurred when GST activity was suppressed may be the mediator for membrane damage. The data argue for a role of GST in maintaining sperm membrane status.

Comparisons of sperm quality, morphometry and function among human sperm populations recovered via SpermPrep II filtration, swim-up and Percoll density gradient methods

The purpose of this study was to compare the morphology/morphometry and fertilizing capacity of human spermatozoa recovered via swim-up method, Percoll density gradient method, and SpermPrep II filtration method. Thirty-three ejaculates were equally divided into 2 aliquots. Aliquot 1 was processed via the direct swim-up method, whereas aliquot 2 was filtered via a SpermPrep II column. The Percoll density gradient method was compared with the SpermPrep II method in a similar protocol using 43 ejaculates. Sperm populations recovered via the SpermPrep II filtration method showed significantly higher hypoosmotic swelling test results, acrosin profiles, and percentage of hyperactivated spermatozoa than sperm fractions recovered by the swim-up method. Furthermore, significant differences were found in most of sperm morphometric parameters between the above sperm populations. However, sperm fractions recovered via the SpermPrep II method did not show significantly different values for these same tests and for most of sperm morphometric parameters compared to the Percoll density gradient method. These results suggest that the SpermPrep II filtration and Percoll density gradient method are equally efficient in isolating sperm subpopulations with better functional parameters than the swimup method.

Review: in vitro spermicidal tests

This review analyzes in vitro spermicidal tests that have been used to evaluate the spermicidal activity of contraceptive products. Special requirements and processes in numerous technologies were also reviewed. Nonoxynol-9 (N-9) was used as an example of a vaginally delivered spermicidal agent, and its spermicidal potency was compared by various spermicidal tests, such as Sander-Cramer, computer-assisted semen analysis, hypoosmotic swelling test, cervical mucus penetration test, and flow cytometry, and advantages and disadvantages of each test were specified. This provides an insight into the different aspects of sperm functionality on which each spermicidal agent exerts its activity. A rationale of the best combination of in vitro spermicidal tests, with particular emphasis on a simple and efficient strategy that targets the complete fertility control, was explained.