EVALUATION OF CELL MEMBRANE INTEGRITY OF SPERMATOZOA BY HYPOOSMOTIC SWELLING TEST – “WATER TEST” IN MICE AFTER INTRAPERITONEAL DAIDZEIN ADMINISTRATION

Evaluation of sperm membrane functionality during epididymal transit in red-rumped agouti (Dasyprocta leporina)

We studied the sperm membrane functionality through the epididymal transit by comparing different hypoosmotic solutions and verifying possible associations among osmotic response and functional parameters of sperm in red-rumped agouti (Dasyprocta leporina). For this purpose, epidydimal sperm from six sexually mature male agoutis were collected via flotation. Then, analyses of sperm parameters and hypoosmotic swelling test using different hypoosmotic solutions (0 mOsm/l, 50 mOsm/l, and 200 mOsm/l) in different regions of the epididymis (caput, corpus, and cauda) were performed. There was an increase (P < 0.05) in the values for sperm concentration, total number of sperm recovered, total and progressive motility, average path velocity, straightline velocity, curvilinear velocity, rapid and medium subpopulations following the caput-corpus-cauda direction. Regardless the hypoosmotic solution, agouti sperm membrane presented similar functional integrity in all the epididymal regions. Moreover, the highest (P < 0.05) osmotic responses were reached at the use of 50 mOsm/l solution in comparison to 0 mOsm/l and 200 mOsm/l for all the regions. Significant correlations among osmotic response and some sperm kinetic parameters were especially observed in epidydimal caput, while no correlations were found in the region of the cauda. In summary, red-rumped agouti sperm present similar membrane functionality during epidydimal transit, but there are evident correlations among such functionality and sperm kinetic parameters, especially at the caput region. Moreover, we indicate the use of a 50 mOsm/l hypoosmotic solution for the analysis of this parameter through the hypoosmotic swelling test.

Urinary Phytoestrogens Are Associated with Subtle Indicators of Semen Quality among Male Partners of Couples Desiring Pregnancy

BACKGROUND

Phytoestrogens have been associated with subtle hormonal changes, although effects on male fecundity are largely unknown.

OBJECTIVE

We evaluated associations between male urinary phytoestrogen (isoflavone and lignan) concentrations and semen quality.

METHODS

This study was a prospective cohort study of 501 male partners of couples desiring pregnancy and discontinuing contraception. Each participant provided up to 2 semen samples that were analyzed for 35 semen quality endpoints the following day. Linear mixed-effects models were used to estimate associations between baseline urinary phytoestrogen concentrations and semen quality parameters, adjusted for age, body mass index (BMI), research site, and serum lipid and cotinine concentrations.

RESULTS

Most associations between urinary phytoestrogens and semen quality parameters were null. However, select individual phytoestrogens were associated with semen quality parameters, with associations dependent on the class of phytoestrogens and modified by BMI. Specifically, genistein and daidzein were associated with a lower percentage of normal sperm and increased abnormalities in semen morphology, with reduced associations observed as BMI increased (P < 0.05) [percentages (95% CIs) of normal morphology by WHO traditional criteria: genistein, main effect: -5.61% (-9.42%, -1.79%); interaction: 0.19% (0.06%, 0.31%) per log unit increase; daidzein, main effect: -5.35% (-9.36%, -1.34%); interaction: 0.18% (0.05%, 0.32%) per log unit increase]. Enterolactone was associated with fewer abnormalities in semen morphometry and morphology and decreased DNA fragmentation, with reduced associations observed as BMI increased (P < 0.05) [percentages (95% CIs) of abnormalities in the neck and midpiece: enterolactone, main effect: -3.35% (-6.51%, -0.19%); interaction: 0.11% (0.01%, 0.21%) per log unit increase].

CONCLUSIONS

These results suggest that male urinary phytoestrogen concentrations characteristic of the US population may be associated with subtle indicators of male fecundity and semen quality but were not associated with couple fecundity.

Soy protein isolates of varying isoflavone content do not adversely affect semen quality in healthy young men

OBJECTIVE

To determine the effects of consumption of soy protein of varying isoflavone content on parameters of semen quality in healthy young men.

DESIGN

Randomized crossover intervention.

SETTING

University campus.

PATIENT(S)

Healthy adult men (age 27.5 ± 5.67 years, body mass index 25.4 ± 3.14 kg/m(2)).

INTERVENTION(S)

Milk protein isolate (MPI), low-isoflavone soy protein isolate (low-iso SPI; 1.64 ± 0.19 mg isoflavones/day, expressed as aglycone equivalents), and high-isoflavone soy protein isolate (high-iso SPI; 61.7 ± 7.35 mg isoflavones/day, expressed as aglycone equivalents) for 57 days each separated by 28-day washout periods.

MAIN OUTCOME MEASURE(S)

Urinary isoflavones were measured from 24-hour urine samples collected on days 54-56 of each treatment period. Semen quality parameters (semen volume, sperm concentration, sperm count, sperm percent motility, total motile sperm count, sperm morphology) were measured from semen samples collected on days 1 and 57 of each treatment period.

RESULT(S)

Urinary isoflavones were significantly higher after consumption of high-iso SPI compared with the low-iso SPI and MPI. Semen parameters, including semen volume, sperm concentration, sperm count, sperm percent motility, total motile sperm count, and sperm morphology, were not significantly affected by consumption of either low- or high-iso SPI compared with MPI.

CONCLUSION(S)

Consumption of soy protein of low or high isoflavone content does not adversely affect semen quality in a sample of healthy adult men.

Effect of long-term administration of zinc after scrotal heating on mice spermatozoa and subsequent offspring quality

This study was set to investigate whether the adverse effects of heat on spermatozoa and subsequent foetuses could be prevented by long-term zinc administration. The scrotums of animals were immersed in water at either 43 degrees C (heat group) or 23 degrees C (control group). Half of the heat and control mice were given 10 mg kg(-1) zinc every other day for 60 days and the others received sterile saline instead of zinc. Heat stress significantly reduced sperm motility, concentration, hypoosmotic swelling-water test (HOS-WT) positive and chromomycin A(3) (CMA(3)) negative spermatozoa at the first 15 days, and the greatest decrease occurred at 30 days (P < 0.05). Sperm motility, concentration and HOS-WT positive spermatozoa were also reduced initially in the zinc administered group, but we did not observe any further decrease in the above mentioned parameters on day 30 (P < 0.05). The weight of foetuses obtained from the females mated with paternal heat treatment males was significantly lower than that of the control group (P < 0.05) and long-term zinc therapy caused a partial recovery (P > 0.05). This study demonstrates that the adverse effects of hyperthermia on semen parameters may be prevented by zinc therapy. Likewise, long-term administration of zinc could improve quality of litter obtained from the females mated with scrotal heat treatment males.