Fatty acid content in epididymal fluid and spermatozoa during sperm maturation in dogs

Abstract

Background: During sperm maturation, there is a reorganization of fatty acids from plasmatic membrane of the spermatozoa, which allows higher membrane integrity and acquisition of sperm motility. However, the fatty acid profile during sperm maturation remains unclear in dogs. Thus, the aim of this study was to identify the fatty acids from the epididymal spermatozoa and plasma during the sperm maturation, and observed changes in the motility and plasmatic membrane parameters. Twenty one adult dogs were used, subsequently to bilateral orchiectomy and epididymal storage, sperm samples were collected from the different segments of the epididymis. Samples were evaluated for conventional microscopy, computer-assisted motility analysis, sperm plasma membrane permeability and the fatty acid analysis (lipids were extracted, transmethylated and analyzed by chromatography).

Results: Caput and corpus sperm showed lower values for the motility variables evaluated and plasmatic membrane integrity, indicating different levels of the fatty acids organization. Saturated, monounsaturated and polyunsaturated fatty acids were in higher concentrations in the spermatozoa from epididymis cauda. Highlighting the presence of caprylic, stearic and docosahexaenoic acids.

Conclusions: These findings demonstrate the influence of the fatty acid profile during sperm maturation, assigning physical and chemical changes in sperm cells, essential for fertilization.

Keywords: Dogs; Epididymis; Fatty acids; Sperm maturation.

Fig. 1

Mean and standard error ($\overline{\mathrm{X}}$ ± SE) of saturated (×10³ mg/dL), monounsaturated (mg/dL), polyunsaturated fatty acids (mg/dL) and docosahexaenoic acid (DHA; mg/dL) in sperm and epididymal fluid according to the epididymal segment (caput, corpus and cauda) in dogs. ^a,bvalues with different superscript letters differ significantly between segments for epididymal sperm (P < 0.05). ^A,Bvalues with different superscript letters differ significantly between segments for epididymal fluid (P < 0.05). *Indicates statistical difference between epididymal fluid and sperm (P < 0.05)