Archives

  • 2018-07
  • 2019-04
  • 2019-05
  • 2019-06
  • 2019-07
  • 2019-08
  • 2019-09
  • 2019-10
  • 2019-11
  • 2019-12
  • 2020-01
  • 2020-02
  • 2020-03
  • 2020-04
  • 2020-05
  • 2020-06
  • 2020-07
  • 2020-08
  • 2020-09
  • 2020-10
  • 2020-11
  • 2020-12
  • 2021-01
  • 2021-02
  • 2021-03
  • 2021-04
  • 2021-05
  • 2021-06
  • 2021-07
  • 2021-08
  • 2021-09
  • 2021-10
  • 2021-11
  • 2021-12
  • 2022-01
  • 2022-02
  • 2022-03
  • 2022-04
  • 2022-05
  • 2022-06
  • 2022-07
  • 2022-08
  • 2022-09
  • 2022-10
  • 2022-11
  • 2022-12
  • 2023-01
  • 2023-02
  • 2023-03
  • 2023-04
  • 2023-05
  • 2023-06
  • 2023-07
  • 2023-08
  • 2023-09
  • 2023-10
  • 2023-11
  • 2023-12
  • 2024-01
  • 2024-02
  • 2024-03
  • Sperm capacitation was negatively r p related with CR while

    2021-11-26

    Sperm capacitation was negatively (r = −0.68; p < 0.001) related with CR while sperm viability was positively (r = 0.69; p < 0.001) related with CR. The correlation between sperm viability and capacitation was negative and significant (r = −0.57; p < 0.001). The correlation between CB1 receptor expression and field conception rate of bulls was moderate but significant (r = 0.57; p < 0.001). The correlation of FAAH expression with bull conception rate was positive but not significant (r = 0.22). No significant relationship was observed between the expression levels of either CB1 receptor or FAAH and any of the sperm quality parameters studied. The scatter plot distribution of spermatozoa expression of CB1 and FAAH genes in the experimental bulls are shown in Fig. 3, Fig. 4B, respectively.
    Discussion Our finding indicates that mRNA levels of CB1 receptor was significantly lower in low fertile bulls compared to high fertile bulls, which is in agreement with Lewis et al. [10] who reported that the mRNA levels of both CB1 and CB2 receptors were lower in infertile than fertile sperm in men. Although earlier studies proposed that AEA-signaling regulate sperm functions required for fertilization in humans [22], and human spermatozoa have been shown to express CB1R at the protein and mRNA level [3], the molecular basis of the involvement of the ECS in controlling sperm function and male fertility in mammals remains unclear [23]. Recently, it has been reported that, in rats, in vivo administration of HU210, a potent agonist of CB receptors, caused a marked impairment of spermatogenesis with reduction in total sperm count and motility, and a deregulation of the ECS, confirming the in vitro observations and indicating that cannabinoids may influence the male fertility [10]. Further, endogenous AEA suppresses LH and testosterone levels in wild-type, but not in CB1 knockout mice [24], providing evidence that the ECS acts to suppress testosterone levels. To the best of our knowledge this is the first study to assess the expression of ECS in spermatozoa in relation to fertility in the bovine. Our results indicate that the mRNA expression of CB1 receptor is positively and significantly related to bull fertility. The role of CB1 is important even at the spermatogenesis itself because it is involved in proper chromatin condensation. It is reported that mammalian male germ Biapenem sale possess a complete ECS from mitotic to haploid cell stage and CB1R is involved in chromatin remodeling during the spermiogenesis and inactivation of CB1 causes an improper histone displacement, poor chromatin condensation and DNA damage in sperm [25,26]. Higher expression of CB1 receptor in high fertile spermatozoa indicates the possibilities of proper chromatin condensation and DNA quality, a hypothesis that needs to be tested. We observed that there was no significant difference in sperm protamine deficiency between high and low fertile bulls. Further, the relationship between CB1 gene expression and protamine deficiency was not significant. Further experiments, using several methods of assessment of sperm DNA integrity, are required to understand the relationship betweenCB1 gene expression and DNA condensation. Further, it has been reported that in the absence of CB1 signaling, sperm acquire motility precociously and the percentage of motile spermatozoa recovered from the caput of epididymis was higher with respect to wild-type mice, suggesting a physiological inhibitory regulation of endocannabinoids on sperm motility in the epididymis [6]. Moreover, AEA exerts these inhibitory effects on sperm functions in several species through CB1 receptor including the inhibition of mitochondrial activity by interfering with mitochondrial electron transport through depletion of NADH and mitochondrial permeability [27], inhibit mitochondrial membrane potential, oxygen consumption and ATP production by preventing the mitochondrial respiratory chain [28], which helps in preserving energy. Thus it is possible that higher expression of CB1 receptor in high fertile bulls facilitates the preservation of energy and ensures gradual acquisition of sperm fertilizing capacity during ascent through the reducing AEA concentrations in the female reproductive tract as was also opined by Rossato et al. [3]. Since it is shown that CB1 play a role in sperm fertility, we assessed two important sperm quality parameters associated with fertilizing potential i. e sperm viability and capacitation to find out the relationship of CB1 gene expression with these sperm functional parameters. We observed that the proportion of viable spermatozoa was lower while the proportion of capacitated spermatozoa was higher in low fertile bulls compared to either medium or high fertile bulls. However, we could not observe a significant relationship of CB1 expression with either sperm viability or capacitation. Further studies, involving several sperm functional parameters are required to understand the relationship between ECS and sperm functions.