Membrane changes during different stages of a freeze–thaw protocol for equine semen cryopreservation

Cryopreservation is an essential tool to preserve sperm cells for zootechnical management and artificial insemination purposes. Cryopreservation is associated with sperm damage via different levels of plasma membrane injury and oxidative stress. Nanoparticles are often used to defend against free radicals and oxidative stress generated through the entire process of cryopreservation. Recently, artificial or natural nanovesicles including liposomes and exosomes, respectively, have shown regenerative capabilities to repair damaged sperm during the freeze–thaw process. Exosomes possess a potential pleiotropic effect because they contain antioxidants, lipids, and other bioactive molecules regulating and repairing spermatozoa. In this review, we highlight the current strategies of using nanoparticles and nanovesicles (liposomes and exosomes) to combat the cryoinjuries associated with semen cryopreservation.

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Evaluating The Efficacy of Selective Inhibition of Arachidonate 15-Lipoxygenase (alox15) During Human Semen Cryopreservation In Protecting Freeze Thaw Induced Sperm Damage

Cryobiology ◽

10.1016/j.cryobiol.2021.11.140 ◽

2021 ◽

Vol 103 ◽

pp. 199

Author(s):

Shubhashree Uppangala ◽

Kavya Rayalla ◽

Huidrom Yaiphaba Meitei ◽

Satish Kumar Adiga

Keyword(s):

Selective Inhibition ◽

Human Semen ◽

Semen Cryopreservation ◽

Freeze Thaw

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Membrane Changes in Polymorphonuclear Leukocytes During Ionophore (A23187) - Induced Lysosomal Release

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010007984x ◽

1977 ◽

Vol 35 ◽

pp. 482-483

Author(s):

P.L. Moore ◽

P.L. Sannes ◽

H.L. Bank ◽

S.S. Spicer

Keyword(s):

Structural Changes ◽

Calcium Release ◽

Clear Understanding ◽

Ionophore A23187 ◽

Enzyme Release ◽

Extracellular Medium ◽

Pmn Leukocytes ◽

Intracellular Ion Concentrations ◽

Membrane Changes ◽

Pmn Leukocyte

It is thought that calcium and/or magnesium may play important roles in polymorphonuclear (PMN) leukocyte functions such as chemotaxis, adhesion and phagocytosis. Yet, a clear understanding of the biological roles of these ions has awaited the development of techniques which permit a selective alteration of intracellular ion concentrations. Recently, treatment of cells with the ionophore A23187 has been used to alter intracellular divalent cation concentrations. This ionophore is a lipid soluble antibiotic produced by Streptomyces chartreusensis that complexes with both calcium and magnesium (3) and is believed to carry these ions across biological membranes (4). Biochemical investigations of human PMN leukocytes demonstrate that cells treated with A23187 and extracellular calcium release their lysosomal enzymes into the extracellular medium without rupturing and releasing their soluble cytoplasmic enzymes (5,6). The aim of the present study and and a companion report (7) was to investigate the structural changes that occur in leukocytes during ionophore-induced lysosomal enzyme release.

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Sarcolemmal permeability changes during early myocardial anoxia

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100084089 ◽

1978 ◽

Vol 36 (2) ◽

pp. 642-643

Author(s):

M. Ashraf ◽

L. Landa ◽

L. Nimmo ◽

C. M. Bloor

Keyword(s):

Cell Membrane ◽

Membrane Permeability ◽

Coronary Artery Occlusion ◽

Artery Occlusion ◽

Cell Membrane Permeability ◽

Enzyme Release ◽

Sprague Dawley ◽

Sprague Dawley Rats ◽

Sarcolemmal Permeability ◽

Membrane Changes

Following coronary artery occlusion, the myocardial cells lose intracellular enzymes that appear in the serum 3 hrs later. By this time the cells in the ischemic zone have already undergone irreversible changes, and the cell membrane permeability is variably altered in the ischemic cells. At certain stages or intervals the cell membrane changes, allowing release of cytoplasmic enzymes. To correlate the changes in cell membrane permeability with the enzyme release, we used colloidal lanthanum (La+++) as a histological permeability marker in the isolated perfused hearts. The hearts removed from sprague-Dawley rats were perfused with standard Krebs-Henseleit medium gassed with 95% O2 + 5% CO2. The hypoxic medium contained mannitol instead of dextrose and was bubbled with 95% N2 + 5% CO2. The final osmolarity of the medium was 295 M osmol, pH 7. 4.

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