7 EFFECTS OF DIFFERENT TRYPSIN SOURCES AND CONCENTRATIONS ON THE VIABILITY OF BOVINE SPERM PRE- AND POST-CRYOPRESERVATION

2007 ◽  
Vol 19 (1) ◽  
pp. 121
Author(s):  
B. A. Blevins ◽  
S. Steenson ◽  
N. M. Loskutoff
Keyword(s):  
Density Gradient ◽  
Density Gradient Centrifugation ◽  
Sperm Quality ◽  
Gradient Centrifugation ◽  
Trypsin Treatment ◽  
Porcine Pancreas ◽  
Bovine Semen ◽  
Progressive Motility ◽  
Bovine Sperm ◽  
Percoll Density Gradient Centrifugation

The goal of this research was to investigate the effect of different sources and concentrations of trypsin on the viability of bovine sperm as a potential method for removing pathogens similar to the washing methods developed for embryos. Trypsin derived from porcine pancreas (Sigma-Aldrich, St Louis, MO, USA) at 2.5% and 0.25% was compared to the recombinant human sequence (TrypLE Select; Invitrogen, Carlsbad, CA, USA) at 10× and 1× concentrations. Cryopreserved bovine sperm (n = 3 bulls) were thawed and processed using discontinuous (90/45) Percoll density gradient centrifugation; the sperm pellets were then washed (10 min at 300g) in TL-HEPES Solution (Cambrex Corp., East Rutherford, NJ, USA) and then resuspended in 1 mL of the same medium. Aliquots of 200 µL of the washed sperm were then added to 1 mL of each of the 4 trypsin treatments as well as a negative control (without trypsin) and incubated at room temperature. Aliquots (25 µL) of each treatment were examined for progressive motility after 5 min. As a result, the control sperm (no trypsin) increased progressive motility by 6.7% and the 1× TrypLE treatment by 9.3%. However, the 10× TrypLE Select and the 10× and 1× porcine pancreas extracts decreased progressive motility by 8.3, 29.0, and 4.0%, respectively. The objective of the second experiment was to determine if the treatment of bovine semen with trypsin (1× TrypLE Select and 0.25% porcine pancreas extract) before or after cryopreservation would affect sperm quality as compared to cryopreservation without trypsin treatment. Raw semen (n = 6 bulls) was collected, evaluated, cryopreserved, and then thawed using a standard bovine method (Biladyl®; Minitube, Verona, WI, USA) without further treatment (control) or after treatment with one of two trypsin treatments (density gradient centrifugation with 1× TrypLE Select or 0.25% porcine pancreas extract in the 45% Percoll layer and a soybean trypsin in activator (Sigma) in the 90% layer) either before freezing (Treat–Freeze) or after thawing (Freeze–Treat). The results for the 6 individual bull samples were comparable and are presented as means (± SEM) compared to the cryopreserved control (no trypsin treatment). Using the Mann–Whitney Rank Sum Test, no differences (P > 0.05) were found in any of the parameters comparing the crypreserved controls (no trypsin treatment) and the 4 treatments: Freeze–Treat vs. Treat–Freeze using either the recombinant TrypLE Select (1×) or the porcine pancreas extract (0.25%). These results suggest that trypsin treatment, before or after cryopreservation, can be used safely on bovine sperm without affecting viability in vitro. Table 1.Comparison of cryopreserved bovine semen without and with various treatments

Purification of dispersed rat adrenal zona glomerulosa cells by Percoll density gradient centrifugation and the isolation of a population of cells highly responsive to adrenocorticotrophin

1986 ◽  
Vol 109 (3) ◽  
pp. 351-NP ◽  
Author(s):  
F. W. Chu ◽  
P. J. Hyatt
Keyword(s):  
Density Gradient ◽  
Density Gradient Centrifugation ◽  
Gradient Centrifugation ◽  
Zona Glomerulosa ◽  
Zona Fasciculata ◽  
Sephadex Column ◽  
Percoll Density Gradient Centrifugation ◽  
Percoll Density Gradient ◽  
Glomerulosa Cells ◽  
Unit Gravity Sedimentation

ABSTRACT Percoll density gradient centrifugation is a simple, inexpensive and convenient method to eliminate contaminating zona fasciculata (ZF) cells from unpurified rat adrenal capsular glomerulosa (ZG) cell preparations (with less than 0·1% ZF cells in the final cell preparation). Basal steroid (aldosterone and corticosterone) output by the purified (PG) cells was unchanged. These purified cells, although free from ZF contamination, were more highly responsive than expected to ACTH (3 nmol/l). When PG cells were further separated by Sephadex column filtration, the filtered PG cells exhibited the steroidogenic response of ZG cells purified by unit gravity sedimentation and Sephadex column filtration, i.e. reduced basal steroid output and an ACTH response reduced to that stimulated by K+ (8·4 mmol/l). Although the cells retained in the column resembled the filtered PG cells ultrastructurally, they showed unchanged basal steroid output and a high ACTH response with increased latepathway activity (the conversion of corticosterone to aldosterone). By combining Percoll density gradient centrifugation and Sephadex column filtration we have a method for the isolation and study of both the high-and low-response rat ZG cells which are free from ZF contamination. J. Endocr. (1986) 109, 351–358

scholarly journals Subpopulations of rat hepatocytes separated by Percoll density-gradient centrifugation show characteristics consistent with different acinar locations

1994 ◽  
Vol 304 (2) ◽  
pp. 617-624 ◽  
Author(s):  
J C Osypiw ◽  
R L Allen ◽  
D Billington
Keyword(s):  
Density Gradient ◽  
Density Gradient Centrifugation ◽  
Gradient Centrifugation ◽  
Rat Hepatocytes ◽  
Marker Enzymes ◽  
Cytotoxic Effects ◽  
Percoll Density Gradient Centrifugation ◽  
Cell Layers ◽  
Density Band ◽  
Percoll Density Gradient

Freshly isolated viable rat hepatocytes were separated into five subpopulations on shallow discontinuous Percoll density gradients. The periportal marker enzymes alanine aminotransferase (ALT), malate dehydrogenase (MDH) and lactate dehydrogenase (LDH) showed gradients of increasing activity from the subpopulation of least density (band 1, rho = 1.07 g/ml) to the subpopulation of greatest density (band 5, rho = 1.09 g/ml). The perivenous marker enzymes pyruvate kinase (PK) and glutamate dehydrogenase (GDH) showed gradients of decreasing activity from band-1 cells to band-5 cells. Glutamine synthetase (GS), which is confined to the two or three cell layers around the hepatic venule, was almost entirely restricted to band-1 hepatocytes. Band-5: band-1 ratios of enzyme activity were as follows: ALT, 8.0; LDH, 2.1; MDH, 1.6; GDH, 0.7; PK, 0.2; GS, 0.01. Band-5:band-1 ratios for ALT, LDH, PK and GS were maintained after culture of subpopulations in identical conditions for up to 72 h, whereas the ratios for MDH and GDH decreased and increased respectively towards unity. Band-1 hepatocytes exhibited greater cytotoxicity than band-5 cells after incubation with carbon tetrachloride or paracetamol. These perivenous-selective toxins produced greater decreases in cell viability and greater release of ALT and LDH from band-1 hepatocytes than from band-5 hepatocytes. Conversely, band-5 hepatocytes were more susceptible than band-1 hepatocytes to the cytotoxic effects of 1-naphthylisothiocyanate and methotrexate (known periportal-selective toxins). It is concluded that band-5 hepatocytes are enriched in periportal cells, whereas band-1 hepatocytes are enriched in perivenous cells. Isolation of hepatocyte subpopulations by Percoll density-gradient centrifugation has the considerable advantage that periportal and perivenous cells can be obtained from the same liver.

Heterogeneity of pituitary adenoma cell subpopulations from acromegalic patients obtained by Percoll density gradient centrifugation

1989 ◽  
Vol 121 (2) ◽  
pp. 270-278 ◽  
Author(s):  
Leo J. Hofland ◽  
Peter M. van Koetsveld ◽  
Theo M. Verleun ◽  
Steven W. J. Lamberts
Keyword(s):  
Pituitary Adenoma ◽  
Density Gradient ◽  
Density Gradient Centrifugation ◽  
Gradient Centrifugation ◽  
Somatostatin Analogue ◽  
Hormone Production ◽  
Α Subunit ◽  
Density Fractions ◽  
Percoll Density Gradient Centrifugation ◽  
Cell Subpopulations

Abstract. Pituitary adenoma cells from 6 acromegalic patients were separated on continuous Percoll density gradients according to differences in their density. Two adenomas produced GH only in culture, the other 4 adenomas produced either GH and PRL (one adenoma) or GH and α-subunit (one adenoma) or GH, PRL and α-subunit (2 adenomas). The cell subpopulations obtained by this technique differed in the amount of hormone production per 105 cells: GH release decreased from the low density fractions to the higher density fractions in 5 of 6 adenomas. Intracellular GH levels completely followed this profile. In the mixed GH/α-subunit adenomas the α-subunit profile completely paralleled the GH profile, whereas in the mixed GH/PRL adenomas the PRL profile showed a pattern different from that of GH (and α-subunit). In neither of the adenomas did we find any differences between the subpopulations with respect to the responsiveness of GH, PRL or α-subunit release to GHRH, TRH and the somatostatin analogue SMS 201-995. Conclusions: 1. Within pituitary adenomas from acromegalic patients heterogeneity exists with respect to hormone production per cell. 2. The cell subpopulations obtained by density gradient centrifugation are not different in their responsiveness to SMS 201-995, GHRH or TRH. 3. Because GH and α-subunit release by the fractions from the mixed GH/α-subunit secreting adenomas were completely parallel, further evidence for co-release of GH and α-subunit by the same tumoural cells is provided.

scholarly journals Improvement of Sperm Quality in Hyperviscous Semen following DNase I Treatment

2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Effrosyni Nosi ◽  
Angelos D. Gritzapis ◽  
Konstantinos Makarounis ◽  
Georgios Georgoulias ◽  
Vasilios Kapetanios ◽  
...  
Keyword(s):  
Density Gradient ◽  
Sperm Motility ◽  
Density Gradient Centrifugation ◽  
Sperm Quality ◽  
Sperm Count ◽  
Gradient Centrifugation ◽  
Dnase I ◽  
Control Group ◽  
First Case ◽  
Dnase Treatment

Semen hyperviscosity impairs sperm motility and can lead to male infertility. This prospective study aimed at assessing the ability of exogenous DNase in improving sperm quality, taking into consideration that DNase has been found in the seminal plasma of several species and that neutrophils release chromatin in order to trap bacteria. A total of seventy-seven semen samples with high seminal viscosity (HSV) as the study group and sixty-two semen samples with normal seminal viscosity (NSV) as the control group were compared in this analysis. These semen samples were divided into three groups of receiving treatment (a) with DNase I at 37°C for 15 min, (b) by density gradient centrifugation, and (c) with a combination of the above two methods. Following a fifteen-minute treatment of hyperviscous semen, the motility of spermatozoa in 83% of semen samples increased to a statistically significant degree. On the contrary, DNase treatment of semen with normal viscosity had no such effects. The above treatment was also accompanied by a significant increase in the percentage of normal spermatozoa, resulting in a major decrease of the teratozoospermia index. Comparison between semen samples that underwent density gradient centrifugation following DNase I treatment, to those collected after density gradient treatment alone, showed that in the first case the results were more spectacular. The evaluation of each preparation in terms of yield (% total progressively motile sperm count after treatment in relation to the initial total sperm count) revealed that the combined approach resulted in 29.8% vs. 18.5% with density treatment alone (p=0.0121). DNase I treatment results in an improvement of sperm motility and morphology and could be beneficial to men with hyperviscous semen in assisted reproduction protocols.

scholarly journals Sperm quality after density gradient centrifugation with three commercially available media: a controlled trial

2014 ◽  
Vol 12 (1) ◽  
pp. 121 ◽  
Author(s):  
Helena Malvezzi ◽  
Rakesh Sharma ◽  
Ashok Agarwal ◽  
Adel M Abuzenadah ◽  
Muhammad Abu-Elmagd
Keyword(s):  
Density Gradient ◽  
Density Gradient Centrifugation ◽  
Sperm Quality ◽  
Controlled Trial ◽  
Gradient Centrifugation
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