Effect of Exogenous Progesterone on Post‐thaw Capacitation and Acrosome Reaction of Bovine Spermatozoa

Abstract

The aim of this work was to study the effect of progesterone (P4) on capacitation and acrosome reaction (AR) of post-thaw bovine spermatozoa in vitro. Spermatozoa were incubated (0-180 min) in capacitation medium supplemented with 0, 0.1, 1.0 and 10.0 microg/ml of P4. At different time intervals aliquots were taken to determine sperm plasma membrane lipid destabilization, or capacitation (AR induced by lysophosphatidylcholine) in spermatozoa. The second experiment aimed to study the effects of P4, as potential inducer of AR in heparin-capacitated spermatozoa. The acrosomal status and viability of spermatozoa were evaluated under an epifluorescence microscope using Ethidium homodimer/peanut agglutinin fluorescein isothiocyanate staining method. Plasma membrane scrambling in spermatozoa was assessed by a flow cytometer, using merocyanine staining. The results show that P4 at the concentrations used had no negative effects on sperm viability. Progesterone significantly enhanced sperm capacitation (p < 0.001), but had no effect on plasma membrane lipid stability (p > 0.05) and did not significantly increase the AR of heparin-capacitated spermatozoa (p > 0.05). Progesterone displayed its effects in a dose-dependent manner with a maximum effect of 10 microg/ml P4 at 180 min of incubation. The results demonstrate that in cryopreserved bovine semen, P4 acts as capacitating, but not as an AR-inducing agent.

Effect of different media additives on capacitation of frozen–thawed ram spermatozoa as a potential replacement for estrous sheep serum

“…Progesterone-and estrogen-supplemented medium yielded low values of Merocyanine þ /YO-PRO-1 À spermatozoa, which displayed a sperm movement pattern different from hyperactivation, consisting of linear motility throughout incubation. Whereas many authors reported that P 4 may act as a capacitating agent [9,12], others suggested that P 4 by itself had no effect on sperm capacitation in bovine [8] and humans [11] unless heparin or BSA was present in the medium. Therefore, although P 4 did play a role in inducing the acrosome reaction in these species, the capacitating effects of the media could be attributed to heparin and BSA both known to be capacitating agents for bovine and human sperm, respectively.…”

“…We sought to investigate the effect of various components known to facilitate sperm capacitation [9,10,12,16,27] for their effect on ram sperm, with the goal of eliminating ESS from the capacitating medium. Specifically, we used an SOF medium to which we added heparin-hypotaurine alone, in combination with P4, E 2 , or BSA, or just b-cyclodextrin.…”

“…For instance, several hormones present in uterine and oviductal fluid at the time of in vivo fertilization and those controlling the estrous cycle, such as progesterone (P4) or estrogens, may be good candidates for triggering in vitro sperm capacitation [7,8]. In this regard, addition of P4 to the capacitation medium exerted a positive effect on sperm membrane cholesterol efflux, hyperactivation, and the acrosome reaction [9][10][11][12]. However, the effect of estrogens on sperm capacitation has been controversial [7,10,13].…”

The Effect of Oestradiol, Progesterone and Heparin on Bovine Spermatozoa Function After Thawing

“…In order to assess the acrosomal status of spermatozoa and to differentiate live spermatozoa from the dead, a combination of two fluorescent dyes (EthD‐1 and PNA‐FITC; Sigma‐Aldrich) was used. Staining was carried out according to the procedure described in Lukoseviciute et al. 2004.…”

Effect of Astaxanthin on Human Sperm Capacitation

“…Acrosome status was monitored with acrosome-specific FITC-labeled peanut ( Arachis hypogaea ) agglutinin (FITC-PNA) in conjunction with DNA-specific fluorochrome propidium iodide (PI) as a viability test [29]. Briefly, AR was induced by incubating aliquots (15 × 10 6 cells) of each sample for a further 30 min at 37 °C, in the presence of 10 μM Ca 2+ ionophore A23187 [11].…”