Time Dependent Impact of Reactive Oxidants on Seminal Attributes of Murrah Bull during Cryopreservation and Storage

Abstract

Background: Cryopreservation is an invaluable technique yet it is also known to be detrimental to sperm function and fertility due to cryo-injury and concomitant generation of reactive oxidants. During laboratory manipulation for the cryopreservation and freeze-thaw process, spermatozoa undergo osmotic stress, ionic imbalance, metabolic decoupling, membrane phase transition, destabilization of the cytoskeleton and antioxidant depletion which communally hampers the semen quality.Methods: With the aim of determining implications of cryopreservation and storage, semen samples were collected by artificial vagina technique from 12 Murrah bulls and subsequently examined at 0 hour (before cryopreservation) and at 24 hour, 1 month and 2 month of storage for various seminal attributes. Simultaneously seminal plasma was separated and preserved at -20oC till the analysis of biochemical indicators of semen quality viz., nitric oxide (NO), total antioxidant quantity (TAC) and lipid peroxidation status (TBARS). Result: A sharp reduction (p less than 0.01) in the semen quality was observed only at 24 h after cryopreservation except for viability. Significant reduction (p less than 0.05) in viable counts was observed up to 1 month interval. The capacitated sperm percentage was greater (p less than 0.01) in the cryopreserved semen as compared to fresh ejaculate. The mean ± SE levels of NO (μmol/L), TAC and TBARS (Units/ml) was 2.31±0.27, 0.73±0.04 and 1.11±0.16 respectively in seminal plasma of neat semen stored at -20oC, while the values in the extended seminal plasma after cryopreservation was 2.37±0.31, 0.44±0.03 and 0.65±0.03 respectively. So it can be inferred that most of the damage encountered by spermatozoa is during the initial period of freezing, but the damage associated by various stressors cannot be ignored.

Impact of Different Levels of Insulin on Cryopreservation Local Roosters Stored Semen Biomarkers

“…The main sites of ROS formation are the mitochondria [16] , rapid temperature changes are particularly vulnerable to damage of sperm cell membrane. [17,18] dilution, cooling, freezing, exposure to cryoprotectants, and thawing, all handling procedures related to semen preparation for storage, induce a higher concentration of malondialdehyde (MDA) and evoke osmotic stress which leads to oxidative stress in the semen [19,20]. Partially, this effect is related to the initial extension of the semen, as semen plasma has been shown to inhibit spontaneous lipid peroxidation.…”

Deciphering dose and time dependent effect of supplementing SNP and L-NAME in extender on progressive motility of Murrah bull spermatozoa

“…RNS include peroxynitrite anion, nitroxyl ion, nitrosyl containing compounds and nitric oxide. RNS particularly NO, depending on magnitude and duration of synthesis can have both beneficial and detrimental effects on spermatozoa (Upadhyay et al 2021a). Thus, a balance between the amount of RNS produced and scavenged will determine whether the motility will be promoted or downgraded.…”