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Tumor necrosis factor-α decreases membrane permeability to Ca(2+) and affects Ca(2+) regulation in sperm cells in vitro, probably via lipid peroxidation, which may explain the decrease in sperm fertilizing capacity during inflammatory and infectious processes.

Background: This study compiles the diversity of sea anemones in different shallow habitats (i.e. rocky shores, coral reefs, mangroves and sandy bottoms) in several locations of Venezuela, including the most important marine reserves of Venezuela:

Inflammation in the male genitourinary tract has been associated with the release of pro-inflammatory cytokines such as interferon-gamma (IFN-γ) and elevated reactive oxygen species, which affects spermatozoa capacitation, motility, and the acrosome reaction, along with functions regulated by the concentration of cytoplasmic Ca(2+) ([Ca(2+)]cyto). Though Ca(2+) signaling is of particular significance in sperm, the effect of IFN-γ intracellular calcium on these cells is still unknown. The present study evaluated the effect of IFN-γ on the [Ca(2+)]cyto and Ca(2+) permeability on human sperm. A cell suspension loaded with fura-2 was incubated with or without IFN-γ (from 0 to 2000 pg/ml) for 0, 30, 60, and 120 minutes, and the [Ca(2+)]cyto was measured. The permeability to Ca(2+) was evaluated by the change of the intracellular concentration following an extracellular Ca(2+) pulse. IFN-γ at low concentrations (≤ 500  pg/ml) did not affect the [Ca(2+)]cyto and Ca(2+) permeability of sperm. At a high concentration (2000  pg/ml), IFN-γ did not alter the [Ca(2+)](cyto), but significantly decreased the magnitude and velocity of Ca(2+) entry into the cell. This effect was dependent on incubation time and IFN-γ concentration. This alteration induced by IFN-γ was prevented by the simultaneous incubation of sperm with the antioxidant butylhydroxytoluene (BHT). In conclusion, in vitro, IFN-γ modifies Ca(2+) sperm membrane permeability, probably via lipid peroxidation. IFN-γ in high concentration, as observed in inflammation/infection, can affect [Ca(2+)](cyto) regulation and alter sperm fertilizing capacity.

Study question Does the evaluation of oxidation-reduction potential (ORP) levels in blood plasma from subfertile patients and oocyte donors represents the ORP status in follicular fluid? Summary answer ORP levels in blood plasma from oocyte donors and sub fertile patients could be an indicator of oxidative stress in follicular fluid What is known already Oxidation-reduction potential (ORP) measurement of seminal plasma is one method to diagnose oxidative stress in male patients, which can help physician to recommend antioxidants administration when it is elevated. Seminal plasma is easily accessible by masturbation. An empirical analogue for semen could be follicular fluid (FF). Unfortunately, it is very difficult to access to FF, unless a surgical procedure is performed. Hence, it is necessary to find indirect parameters to evaluate the ORP status in FF. Since blood plasma (BP) circulation provides antioxidants to the FF, we studied the BP ORP measurement to indirectly determine ORP levels in FF. Study design, size, duration Prospective study conducted at CITMER, Mexico from December 2022 to January 2023. We included under informed consent 15 oocyte donors (age 26.8 ± 4.06 years old) and 55 patients (age 35.2 ± 4.8 years old) undergoing IVF/ICSI. Participants/materials, setting, methods ORP levels in BP and FF from dominant follicles were measured at the same time of oocyte collection with MiOXSYS system. Oocytes were inseminated and zygotes were cultured until blastocysts stage. We calculated correlation of a) ORP levels in FF vs BP, b) ORP of FF and BP vs number of retrieved oocytes, c) ORP of FF and BP vs number of fertilized oocytes, d) ORP of FF and BP vs number of blastocysts Main results and the role of chance A total of 172 oocytes from oocyte donors were collected. After fertilization check, 135 zygotes (78%) were observed. A total number of 55 blastocysts (31%) were observed at day 5 + day 6. For patients, a total of 550 oocytes were collected, 360 zygotes were observed (65%) and 164 blastocysts at day 5 + day 6 were obtained (45%). The correlation between ORP levels from FF and BP for oocyte donors was 0.90 and 0.51 for patients. The overall ORP levels in FF and BP in patients were 136.2 ± 14.9 mV and 148.3 ± 15.97 mV, respectively. For oocyte donors, ORP levels in FF and BP were 160.3 ± 13.8 mV and 170.28 ± 17.67mV, respectively. There was a mild correlation of ORP levels in BP with numbers of oocytes retrieved (r = 0.25). The correlation of BP ORP with oocyte fertilization was 0.24 in patients with autologous oocyte utilization. The mean ORP levels of FF were 136.2 ± 14.9 mV, versus a mean ORP of 148.3 ± 15.97 mV in BP. The FF ORP levels between 100-150 mV [LRD1] were moderately correlated and predictive of blastocyst development [LRD2]. For donor oocytes there was a weak negative correlation [LRD3] of FF ORP with oocyte fertilization (-0.06) and a weak negative correlation for blastocyst formation was found (-0.18). Limitations, reasons for caution The MiOXSYS System ( Careous Biotechnology, Lituania) is a device calibrated to measure ORP levels in seminal plasma but not to measure ORP levels in FF nor BP. The number of analyzed data should be increased. Wider implications of the findings According to this study, the use of blood plasma to surrogate the measurements of ORP levels in follicular fluid could represent a further strategy to include female patients to be treated by antioxidants before an IVF treatment. Trial registration number None