During transit through the female reproductive tract, mammalian spermatozoa are exposed to increasing concentrations of progesterone (P4) released by the cumulus oophorus. P4 triggers massive calcium influx into human sperm through activation of the sperm-specific calcium channel CatSper. These properties of human spermatozoa are thought to be unique since CatSper is not progesterone sensitive in rodent sperm. Here, by performing patch clamp recording from spermatozoa from rhesus macaque for the first time, we report that they express P4-sensitive CatSper channel identically to human sperm and react to P4 by inducing responsiveness to zona pellucida, unlike human sperm, which respond directly to P4. We have also determined the physiologic levels of P4 capable of inducing capacitation-associated changes in macaque sperm. Progesterone (1 μM) induced up to a 3-fold increase in the percentage of sperm undergoing the zona pellucida-induced acrosome reaction with the lowest threshold as low as 10 nM of P4. Submicromolar levels of P4 induced a dose-dependent increase in curvilinear velocity and lateral head displacement, while sperm protein tyrosine phosphorylation was not altered. Macaque spermatozoa exposed to 10 μM of P4 developed fully hyperactivated motility. Similar to human sperm, on approaching cumulus mass and binding to zona pellucida, macaque spermatozoa display hyperactivation and undergo an acrosome reaction that coincides with the rise in the sperm intracellular calcium. Taken together, these data indicate that P4 accelerates the completion of capacitation and provides evidence of spermatozoa "priming" as they move into a gradient of progesterone in search for the oocyte.

OBJECTIVE To characterize physical examination, plasma biochemical, and ultrasonographic findings in aquarium-housed, managed semiwild, and wild southern stingrays (Hypanus americanus) with and without reproductive disease. ANIMALS Southern stingrays from aquarium (n = 48), lagoon (managed semiwild; 34), and wild (12) habitats. PROCEDURES Limited, opportunistic prosections were performed of presumed anatomically normal wild southern stingrays and compared with findings for aquarium-housed stingrays with reproductive disease. Ultrasonographic video data from both groups were used to assign a score (1 to 5) indicating increasing severity of ovarian and uterine reproductive disease. Plasma total 17β-estradiol, estrone, progesterone, and testosterone concentrations were measured with enzyme immunoassays validated for use in southern stingrays. RESULTS Ultrasonographic ovarian scores were significantly correlated with uterine scores. No reproductive disease was detected in semiwild or wild stingrays, but 65% (31/48) of aquarium-housed stingrays had developing or advanced reproductive disease (ie, ultrasonographic ovarian or uterine score of 4 or 5). Significant correlations were identified between ovarian and uterine disease status and plasma concentrations of all steroid hormones except testosterone. CONCLUSIONS AND CLINICAL RELEVANCE Findings suggested that ultrasonography and plasma hormone concentrations may be useful in the identification of reproductive disease and determination of disease severity in southern stingrays.

ABSTRACT. It has been shown that addition of the surfactant Orvus ES paste (OEP) and its main component sodium lauryl sulfate (SLS) to boar or dog semen before freezing improves post-thaw sperm motility and protects acrosome caps. In this study, we investigated the usefulness of the addition of OEP (0, 1, 2 and 4%) or SLS (0, 1, 2, 3 and 4 mg/ml) to cat ejaculates before freezing and their concentrations. Among the OEP addition groups, the 1% OEP group showed higher sperm motility than the other groups. Among the SLS addition groups, the 3 mg/ml SLS group showed slightly higher sperm motility and viability than the other groups. Comparison between the 1% OEP and 3 mg/ml SLS addition groups suggested a higher percentage of sperm with an acrosome cap in the 1% OEP group. The other sperm properties did not significantly differ between the 2 groups. These results indicate that addition of 1% OEP or 3 mg/ ml SLS is effective for freezing of cat ejaculated semen.KEY WORDS: acrosome cap, cat, frozen semen, orvus es paste, sodium lauryl sulfate.J. Vet. Med. Sci. 72(1): 23-27, 2010 In regard to artificial insemination (AI) with frozen feline semen, intravaginal [6,11,19] and intrauterine [6,18,19] inseminations with ejaculates have each been reported in three studies, and intravaginal [20] and intrauterine [15,20] inseminations with epididymal sperm have each been reported in one and two studies, respectively. In our 2003 year study using epididymal sperm [15], we added 7% (v/v) glycerol and 1% Orvus ES paste (OEP, also known as Equex STM paste, Nova Chemical Sales, Inc., Scituate, MA, U.S.A.) to semen as cryoprotective agents and achieved a conception rate of 27.3%. However, we did not evaluate the usefulness of addition of OEP for cryopreservation of feline semen or its optimal concentration. Addition of OEP along with glycerol for the cryopreservation of boar [12] and dog [16,17] semen has been shown to protect the acrosome caps of sperm, thereby increasing and maintaining post-thaw sperm motility for a long period of time. In 2004, Axnér et al. [5] investigated the usefulness of Equex STM paste for cryopreservation of feline epididymal sperm and showed that addition 0.5% (v/v) Equex STM paste led to greater protection of the acrosome caps of sperm after freeze-thawing than no addition, but sperm motility was lower (sperm survival was shorter) 4-6 hr after thawing than in the case of no addition. Our search of the literature revealed no studies in which addition of OEP for semen cryopreservation adversely affected post-thaw sperm motility. It remains unclear whether the results of the study by Axnér et al. [5] regarding cryopreservation of epididymal sperm apply to cryopreservation of cat ejaculates.OEP is known to contain mainly sodium lauryl sulfate (SLS), but data on its concentration and the remaining constituents have not been published. It has been suggested that the effect of SLS might be exerted by modifying the structure of egg yolk lipoproteins in the extracellular medium [4]. Kato et al. [9] employed ...

This study indicates that macaque sperm survive cooling optimally when cooling rates range from -17 to -34°C/minute. Conversely, slow cooling was detrimental and resulted in poor quality sperm.

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