Epididymal maturation affects calcium regulation in equine spermatozoa exposed to heparin and glucose.
Abstract: Spermatozoal function is affected by the ability to regulate intracellular calcium concentrations ([Ca2+]i), and may be influenced by epididymal maturation as well as environmental components. Regulation of [Ca2+]i in ejaculated and epididymal stallion spermatozoa was monitored over time in various media. Spermatozoa from each of 5 pony stallions (3 ejaculate samples and 1 caput and cauda sample) were labeled with the fluorescent calcium indicator probe Indo-1 in a calcium-free modified Tyrode's buffer. Fluorescent emissions were monitored by a dual wavelength spectrofluorometer over 5 h. Calcium (1 mM) was added at T = 15 min, and heparin (HEP; 10 micrograms/ml) or heparin plus glucose (hGLUC; 5 mM in 10 micrograms/ml heparin) was added at T = 30 min. Spermatozoal Ca2+ content and regulation differed among males (P = 0.0066). Relative initial [Ca2+]i differed significantly among all stages of maturity (0.84 +/- 0.104, 0.76 +/- 0.023, 1.20 +/- 0.036 LSM of relative Ca2+ units for caput, cauda and ejaculate spermatozoa respectively; P = 0.001). Rate of Ca2+ uptake was similar for ejaculate and cauda spermatozoa (0.021 +/- 0.005 and 0.026 +/- 0.002 relative Ca2+ units/sec) but slower for caput spermatozoa (0.012 +/- 0.001; P = 0.0006). There was no immediate effect of HEP or hGLUC in any stage (P > 0.05), and caput spermatozoa did not differ from cauda spermatozoa for any treatment or time period. A significant increase in [Ca2+]i was seen in ejaculate spermatozoa treated with HEP from 2 h on (P < 0.05). This study demonstrates that both the absolute Ca2+ concentration and the rate of Ca2+ internalization in equine spermatozoa is dependent on the stage of maturation. Ejaculate spermatozoa respond to heparin through increased [Ca2+]i, which may play a role in the fertilizing ability of ejaculate spermatozoa.
Publication Date: 2000-03-25 PubMed ID: 10732046DOI: 10.1016/s0093-691x(98)00018-1Google Scholar: Lookup
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
- Journal Article
- Research Support
- Non-U.S. Gov't
Summary
This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.
This research studies how the maturity of horse sperm and exposure to certain elements can influence its ability to regulate calcium levels. It shows that calcium level and rate of calcium absorption in horse sperm depend on maturity level, and that it responds to the compound heparin.
Study Background
- The study proposes that sperm function is impacted by the ability to control internal calcium concentrations ([Ca2+]i). It suggests that this could be influenced by the sperm’s maturity as and exposure to particular environmental components.
Research Methodology
- Sperm samples were taken from five pony stallions and the regulatory elements of calcium concentration were monitored over defined periods. These samples included ejaculates and samples from the caput and cauda regions of the epididymis, which are stages of sperm maturity.
- The sperm samples were labelled with a fluorescent calcium indicator probe and the emissions were monitored using a dual wavelength spectrofluorometer over the duration of 5 hours.
- Calcium was added at the 15-minute mark, and heparin alone or heparin and glucose together were added at 30 minutes.
Key Observations
- The study found that calcium levels in the sperm varied among the male subjects.
- It was observed that the sperm’s maturity stage significantly influenced the initial calcium levels.
- Moreover, the study found that calcium uptake was similar for ejaculated sperm and mature sperm from the cauda, but slower for immature caput sperm.
- No immediate effects of heparin or heparin plus glucose were observed with any stage of maturity.
- However, a significant increase in calcium levels was noted in ejaculated sperm treated with heparin from the second hour onwards.
Implications of the Study
- The research shows that the absolute calcium concentration and the rate of calcium absorption in horse spermatozoa depend on the maturity stage.
- Furthermore, the study suggests that heparin interacts with ejaculate spermatozoa, leading to increased calcium levels, which might have implications on sperm’s ability to fertilize.
Cite This Article
APA
Merkies K, Buhr MM.
(2000).
Epididymal maturation affects calcium regulation in equine spermatozoa exposed to heparin and glucose.
Theriogenology, 49(3), 683-695.
https://doi.org/10.1016/s0093-691x(98)00018-1 Publication
Researcher Affiliations
- Department of Animal and Poultry Science, University of Guelph, Ontario, Canada.
MeSH Terms
- Animals
- Calcium / metabolism
- Ejaculation
- Epididymis / physiology
- Fluorescent Dyes
- Glucose / pharmacology
- Heparin / pharmacology
- Homeostasis
- Horses / physiology
- Male
- Spermatozoa / drug effects
- Spermatozoa / physiology
Citations
This article has been cited 0 times.Use Nutrition Calculator
Check if your horse's diet meets their nutrition requirements with our easy-to-use tool Check your horse's diet with our easy-to-use tool
Talk to a Nutritionist
Discuss your horse's feeding plan with our experts over a free phone consultation Discuss your horse's diet over a phone consultation
Submit Diet Evaluation
Get a customized feeding plan for your horse formulated by our equine nutritionists Get a custom feeding plan formulated by our nutritionists
