Absence of glucose decreases human fertilization and sperm movement characteristics in vitro

Abstract

The effect of glucose in a modified Ham's F10 medium (MM) without hypoxanthine, phosphate and transition metals on human fertilization and sperm survival in vitro was determined. Mature human oocytes from in-vitro fertilization (IVF) patients or Percoll-washed human spermatozoa were randomly allocated to one of the treatment groups: normal Ham's F10, MM, MM with 5 mM glucose (HGMM) and MM with 0.5 mM glucose (LGMM). Oocytes were inseminated in one of the four media for 12-20 h and checked for fertilization. Sperm were incubated likewise for 4 and 24 h, and sperm motility and sperm movement characteristics including average path velocity (VAP), curvilinear velocity (VCL), straight line velocity (VSL), amplitude of lateral head displacement (ALH), beat cross frequency (BCF), straightness (STR), and linearity (LIN) were determined using computer-assisted semen analysis. Fertilization rates were significantly lower in oocytes cultured in MM (23.8%) compared to LGMM (75.5%), HGMM (73.6%) or Ham's F10 (71.1%). Sperm characteristics after 4 h incubation in all four media were similar, except VAP, VSL, VCL and ALH were significantly lower in MM (no glucose) in comparison with the other three media. After 24 h VAP, VSL, VCL, ALH, LIN and percentage rapid spermatozoa were significantly higher in spermatozoa incubated in HGMM or Ham's F10 compared with MM or LGMM. Also after 24 h, the percentage of spermatozoa which were highly motile was greater in HGMM than in Ham's F10. Absence of glucose significantly lowered fertilization rates and sperm movement characteristics in vitro.

High glucose concentrations per se do not adversely affect human sperm function in vitro

“…To become functionally competent, spermatozoa must undergo capacitation within the female tract (Ecroyd et al 2003) and even though glucose has been reported to be beneficial for human sperm capacitation (Mahadevan et al 1997, Williams & Ford 2001, the present results suggest that high glucose levels do not interfere with this process. To our knowledge the present report is the first to address the effects of high glucose levels on capacitation.…”

“…In accordance, a number of studies have already demonstrated that the capacitation of human spermatozoa substantially relies on glucose, which suggests a key role for glucose in sustaining hyperactivation (Williams & Ford 2001), in tyrosine phosphorylation (Travis et al 2001), and in ensuring IVF (Rogers & Perreault 1990, Mahadevan et al 1997. However, it is still unclear whether the beneficial effects of glucose derive from the provision of extra metabolic energy through glycolysis or from the generation of other metabolic products (Aitken et al 1997, De Lamirande et al 1997, Williams & Ford 2001.…”

“…Sperm samples, with an adjusted concentration of 10!10 6 spermatozoa/ml, were then incubated at 37 8C and 5% CO 2 in PBS supplemented with 0.9 mM CaCl 2 , 0.5 mM MgCl 2 , 0.3% (w/v) BSA, 1 mM sodium pyruvate, 10 mM sodium lactate, and 1% (v/v) penicillin/streptomycin, pHZ7.4 (Tavares et al 2013, 2015, Sousa et al 2014, as well as D-glucose at either: i) 5 mM, the optimal concentration for sperm preparation in vitro (Mahadevan et al 1997; ii) 25 mM to mimic the diabetic condition; or iii) 50 mM to evaluate cell response to massive doses of glucose. To control for the possible effects of the increased solution osmolarity being driven by the elevated concentrations of D-glucose, equal concentrations of L-glucose, a non-metabolizable and non-physiologic form of glucose, was used as a control.…”

Unraveling the sperm proteome and post-genomic pathways associated with sperm nuclear DNA fragmentation

“…Nevertheless, anaerobic glycolysis seems to be the most important source of energy to human sperm, and is important to sperm motility [67,68], capacitation [69], and fertilization ability [67]. Triacylglycerols are a source of fatty acids, which are also important for sperm metabolism [70,71].…”

Moving to the beat: a review of mammalian sperm motility regulation

“…These differences are of profound importance when handling gametes in vitro. For example, glucose will inhibit capacitation in bull sperm, but is required for capacitation in mouse sperm.The role of glucose in sperm metabolism of other species remains under investigation (Quinn et al 1995;Mahadevan et al 1997;Barak et al 1998;Williams and Ford 2001).…”