journal

Preservation of boar semen at 18 ◦C induces lipid
peroxidation and apoptosis like
changes in spermatozoa

A. Kumaresan ∗, G. Kadirvel, K.M. Bujarbaruah 1, R.K. Bardoloi, Anubrata Das2, Satish Kumar, S. Naskar Artificial Insemination Laboratory, Division of Animal Production, ICAR Research Complex for NEH Region, Barapani, Umiam, Meghalaya 793103, India

Received 13 August 2007; received in revised form 10 January 2008; accepted 13 January 2008
Available online 18 January 2008

Abstract

Boar sperm functions, lipid peroxidation status, mitochondrial membrane potential (Ψm) and membrane permeability (apoptosis like features) were assessed during liquid preservation. Four ejaculates each from four Hampshire boars were extended with Beltsville Thawing Solution and preserved at 18 ◦C. At 0, 24, 48, 72 and 96 h of storage, each ejaculate was examined for sperm functions, lipid peroxidation, Ψm, and membrane permeability. The lipid peroxidation status of the spermwas assessed based on the malonaldehyde (MDA) levels. Detection ofΨm was done using 3,3-dihexyloxacarbocyanine iodide [DiOC6(3)]/propidium iodide (PI) assay and Yo-pro-1/PI assay was used to detect change in plasma membrane permeability. The sperm motility, viability and acrosomal integrity declined significantly (p < 0.05) from 0 to 96 h of preservation. At the start of the preservation, the MDA levels (nM/109 sperm) were low in sperm (99.83±2.69) and seminal plasma (191.98±11.58), which gradually increased up to the 96 h of storage. Highest negative correlation (r value) was observed between MDA levels and sperm motility (−0.97), live percent (−0.97), acrosomal integrity (−0.97) and hypo-osmotic sperm swelling test (HOSST) positive sperm percentage (−0.98). Strong positive correlation was observed between HOSST positive sperm percentage and intact acrosome percentage (r = 0.98). There was a significant (p < 0.05) increase in the sperm cells with low Ψm from 0 to 96 h of preservation. Before preservation, 14.85±4.66% of sperm cells of the ejaculate showed low mitochondrial membrane potential, whereas after 96 h of preservation, this proposition of cells increased up to 32.00±6.25%. The apoptotic sperm population was 8.33±2.31% in fresh semen, while this population was 25.19±4.25% at 96 h of preservation and the difference was significant (p < 0.05). The findings of the

∗ Corresponding author. Tel.: +91 364 2570362.
E-mail address: ogkumaresan@rediffmail.com (A. Kumaresan).
1 Animal Science Division, Krishi Bhavan, New Delhi, India.
2 National Research Centre on Pig, Guwahati, Assam, India.
0378-4320/$ – see front matter © 2008 Elsevier B.V. All rights reserved.
doi:10.1016/j.anireprosci.2008.01.006