scholarly journals Low-density Lipoprotein Improves Motility and Plasma Membrane Integrity of Cryopreserved Canine Epididymal Spermatozoa

2015 ◽  
Vol 29 (5) ◽  
pp. 646-651 ◽  
Author(s):  
N. Prapaiwan ◽  
T. Tharasanit ◽  
S. Punjachaipornpol ◽  
D. Yamtang ◽  
A. Roongsitthichai ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Low Density Lipoprotein ◽  
Membrane Integrity ◽  
Density Lipoprotein ◽  
Low Density ◽  
Plasma Membrane Integrity ◽  
Epididymal Spermatozoa

scholarly journals Effectiveness of tes-tris or tris association with low density lipoprotein on in vitro longevity of refrigerated buffalo semen

2020 ◽  
Vol 72 (3) ◽  
pp. 729-736
Author(s):  
J. Almeida ◽  
M.F. Brito ◽  
V.A.B. Becerra ◽  
B.P. Neves ◽  
P.A. Auler ◽  
...  
Keyword(s):  
Low Density Lipoprotein ◽  
Membrane Integrity ◽  
Density Lipoprotein ◽  
Fixed Time ◽  
Computer Assisted ◽  
Low Density ◽  
Promising Alternative ◽  
Sperm Analysis ◽  
Buffalo Semen

ABSTRACT This study investigated in vitro the efficacy of four different extenders (TES-TRIS and TRIS with LDL low-density lipoprotein at concentrations of 10 or 5%) on the longevity of buffalo sperm in the refrigeration process at 5ºC. Sperm motility was assessed every 24 hours up to 72 hours of incubation using computer assisted sperm analysis and sperm membrane integrity was examined by the hypoosmotic test (HOST) at T1, T24, T48 and T72 hours. Eleven buffaloes (1 ejaculate per buffalo) of the Murrah breed were used, ranging in age from 4 to 5 years. Immediately after collection, each ejaculate was fractionated into 4 aliquots, and each aliquot was diluted in one of four diluents to obtain 50x106SPTZ/mL. The samples were packed in 0.5mL straws and refrigerated (-0.25°C/min) to 5°C and maintained at this temperature until evaluation. Prior to evaluation the samples were heated at 37°C for 30 seconds. The statistical package used for analysis was STATA 12.0 "Statistical Analysis Software" and means were compared by the Friedman test (P<0.05). The results of sperm kinetics and HOST indicate that the TRIS diluent with 10% LDL could be a promising alternative for semen refrigeration at 5ºC, to be used in conventional and fixed time artificial insemination.

scholarly journals Topography and dynamics of receptors for acetylated and malondialdehyde-modified low-density lipoprotein in the plasma membrane of mouse peritoneal macrophages as visualized by colloidal gold in conjunction with surface replicas.

1984 ◽  
Vol 32 (10) ◽  
pp. 1017-1027 ◽  
Author(s):  
H Robenek ◽  
G Schmitz ◽  
G Assmann
Keyword(s):  
Plasma Membrane ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Peritoneal Macrophages ◽  
Carbon Surface ◽  
Low Density ◽  
Double Labeling ◽  
Ldl Receptors ◽  
Receptor Sites ◽  
Mouse Peritoneal Macrophages

The topography and dynamics of receptors for acetylated (acetyl) and malondialdehyde-modified (MDA) low-density lipoprotein (LDL) in the plasma membrane of cultured mouse peritoneal macrophages were investigated using a new technique. Modified LDL labeled with gold particles was used to visualize LDL receptors in the plane of the plasma membrane in platinum-carbon surface replicas of critical point-dried cells. It was found that the native distribution of unoccupied acetyl-LDL receptors is diffuse, whereas unoccupied MDA-LDL receptors are preclustered in the plasma membrane. Competition and double labeling experiments suggest the existence of two distinct classes of receptor sites for acetyl-LDL and MDA-LDL.

Oxidized low density lipoprotein inhibits platelet plasma membrane Ca2+-ATPase

Cell Calcium ◽  
1996 ◽  
Vol 19 (5) ◽  
pp. 453-458 ◽  
Author(s):  
B. Zhao ◽  
R. Dierichs ◽  
F.N. Miller ◽  
W.L. Dean
Keyword(s):  
Plasma Membrane ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Low Density ◽  
Oxidized Low Density Lipoprotein

scholarly journals The protein and the gene encoding the receptor for the cellular uptake of transcobalamin-bound cobalamin

Blood ◽  
2009 ◽  
Vol 113 (1) ◽  
pp. 186-192 ◽  
Author(s):  
Edward V. Quadros ◽  
Yasumi Nakayama ◽  
Jeffrey M. Sequeira
Keyword(s):  
Plasma Membrane ◽  
Sodium Dodecyl Sulfate ◽  
Gel Electrophoresis ◽  
Low Density Lipoprotein ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Density Lipoprotein ◽  
Low Density ◽  
Lipoprotein Receptor ◽  
Density Lipoprotein Receptor

Abstract The transcobalamin (TC, TCII) receptor (TCblR) on the plasma membrane binds TC- cobalamin (Cbl) and internalizes the complex by endocytosis. This receptor was purified from human placental membranes by affinity chromatography. Tryptic digest of the protein extracted from a sodium dodecyl sulfate-polyacrylamide gel electrophoresis gel and subjected to liquid chromatography/mass spectrometry identified 4 peptides that matched with a membrane protein in the data bank. TCblR belongs to the low-density lipoprotein receptor family, with 2 low-density lipoprotein receptor type A domains separated by a complement-like cysteine-rich region. The 282-amino acid sequence includes a signal peptide of 31 residues, extracellular domain of 198 residues, a transmembrane region of 21 residues, and a cytoplasmic domain of 32 residues. The binding of TC-Cbl does not require the cytoplasmic domain or its orientation in the plasma membrane because the recombinant extracellular domain binds TC-Cbl with high affinity and specificity. The protein is heavily glycosylated and accounts for the 58-kDa size by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The human gene first identified as 8D6A and more recently as CD 320 encoding TCblR is located at p13.2 on the short arm of chromosome 19, spans a length of 6.224 kb, and is composed of 5 exons and 4 introns.

scholarly journals 211QUALITY CHANGES IN BLUE WILDEBEEST (CONNOCHAETES TAURINUS) EPIDIDYMAL SPERMATOZOA MAINTAINED AT 4°C

2004 ◽  
Vol 16 (2) ◽  
pp. 227
Author(s):  
F. Olivier ◽  
T. Spies ◽  
F. Martinez-Pastor ◽  
D.M. Barry ◽  
P. Bartels
Keyword(s):  
Plasma Membrane ◽  
Assisted Reproduction ◽  
Sperm Quality ◽  
Osmotic Shock ◽  
Membrane Integrity ◽  
Molecular Probes ◽  
Assisted Reproduction Techniques ◽  
Plasma Membrane Integrity ◽  
Epididymal Spermatozoa ◽  
Connochaetes Taurinus

Wildlife management in southern Africa often involves the harvesting of animals on ranches and reserves, providing unique opportunities to collect and assess the quality of epididymal spermatozoa for possible future conservation actions. The black wildebeest (Connochaetes gnu) is facing renewed threats to its survival, including the production of fertile hybrids from crossing with the more common blue wildebeest (Connochaetes taurinus). The close relationship between the two wildebeest species allows for the blue wildebeest to be used as a model to assess epididymal sperm quality over time while maintained at 4°C. Field conditions often preclude the immediate availability of liquid nitrogen, necessitating the development of alternative short-term storage methods. All chemicals were provided by Sigma (South Africa) unless otherwise stated. Testes were harvested from 6 blue wildebeest bulls at a local game farm, Savannah, and kept at 5°C during transportation to the lab. Epididymides were dissected out and spermatozoa were flushed out of the cauda epididymis using 1mL of Tris-citrate egg yolk extender (Fraction A, Biladyl, Minitub, Germany), followed by storage at 4°C and assessment at 12h intervals. At each interval, an aliquot was removed, washed with a modified buffered HEPES solution (20mM HEPES, 355mM sucrose, 10mM glucose, 2.5mM KOH;; 400mOsm/kg, pH 7; Sigma) and visually assessed with a phase contrast microscope (×200, at 37°C) to determine the percentage of motile (MS) and progressive motile (PS) spermatozoa. In addition, plasma membrane integrity (PMI) was assessed with eosin-nigrosin staining and active mitochondrial status (MIT) assessed with an epifluorescent microscope (×400) using the fluorescent probe JC-1 (Molecular Probes, The Netherlands;; 7.5μM; 30min at 37°C). Resilience to hypo-osmotic shock was also evaluated by incubating the sample in a modified hypo-osmotic medium (100mOsmkg−1; 15min RT), and staining with PI to assess plasma membrane integrity (HOSPMI). A summary of results is presented in the table 1. The MS, MIT and HOSPMI did not decrease significantly during the 48h storage period. The only parameters that showed a significant decrease were PS and PMI (P&lt;0.01, Kruskall-Wallis test). However, PMI showed a slow but steady decrease (13%), whereas PS underwent a significant drop (52%). In conclusion, epididymal spermatozoa from the blue wildebeest, kept at 4°C for 48h, may still be useful for some assisted-reproduction techniques. The use of spermatozoa from a common but closely related wildebeest species allows for the development of assisted-reproduction techniques that may one day aid the conservation of threatened wildebeest species. Additional research is needed to confirm these findings and to test the effect of longer storage times on spermatozoa of this species as well as closely related endangered species. Table 1 Parameters measured during the 12-h time periods (mean±SD)

95 EFFECT OF CRYOPROTECTANT ADDITION AND REMOVAL AT 4°C ON MOTILITY AND PLASMA MEMBRANE INTEGRITY OF BOVINE CAUDAL EPDIDYMAL SPERMATOZOA

2006 ◽  
Vol 18 (2) ◽  
pp. 156
Author(s):  
C. Guerrero ◽  
S. Leibo ◽  
D. Paccamonti ◽  
B. Eilts ◽  
K. Bondioli ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Semen Analysis ◽  
Membrane Integrity ◽  
Egg Yolk ◽  
Single Step ◽  
Freezing Process ◽  
Computer Assisted ◽  
Chemical Toxicity ◽  
Plasma Membrane Integrity ◽  
Epididymal Spermatozoa

Cryopreservation of spermatozoa harvested from the epididymides would be a means of salvaging germplasm from genetically valuable males that die unexpectedly from injury, disease, or poaching. It is well known that the addition of cryoprotective agents (CPAs) is essential for sperm survival following the freezing process. However, CPAs can cause loss in sperm viability due to osmotic damage or chemical toxicity. The objective of this study was to determine the effects of single-step addition and/or removal of glycerol (GLY) or ethylene glycol (EG) on motility and plasma membrane integrity of bovine epididymal spermatozoa. Paired testes were obtained from mature bulls (n = 10) at a local abattoir and transported to the laboratory at 25–28°C within 4–6 h post-mortem. Epididymal spermatozoa were harvested by multiple incisions from the caudae epididymides of each bull, pooled, and washed in Brackett-Oliphant medium by centrifugation for 5 min at 500g. Pellets were resuspended in egg yolk-Tris-glucose-citric acid monohydrate medium (EYT-GC) at a concentration of 120 × 106 cells/mL and cooled to 4°C at a rate of 0.1°C/min. Specimens were allocated to each of five treatment groups: control (no CPA), 7% GLY, and 14% GLY, 7% EG, 14% EG. Then, replicate samples were diluted 1:1 in EYT-GC medium containing twice the final desired concentration of CPA. After being exposed for 10 min, each sample was diluted directly into EYT-GC at 4°C. Motility was assessed by means of a computer assisted semen analysis system and plasma membrane integrity was determined by SYBR 14 and propidium iodide staining followed by fluorescence microscopy. Differences among treatments were analyzed using one way ANOVA (P < 0.05). The results (Table 1) show that maximum survival, as assessed by measurements of motility and membrane integrity, was achieved with spermatozoa exposed to 7% EG. Almost identical intermediate levels of survival were observed with spermatozoa exposed to 7% GLY or 14% EG. The lowest survival was observed for spermatozoa exposed to 14% GLY. The results indicate that the use of EG as a cryoprotectant may minimize toxicity and osmotic damage to fresh bovine epididymal spermatozoa. Its efficacy as a CPA is currently being determined. Table 1. Sperm motility and membrane integrity (mean ± SEM) after addition of CPA to epididymal sperm

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