Home About us Contact
|
Home About us Contact | ||
|
|
||
mOsmol Kg (mosmol + kg)
Selected AbstractsA role for the volume regulated anion channel in volume regulation in the murine CNS cell line, CADACTA PHYSIOLOGICA, Issue 2 2010V. L. Harvey Abstract Aim:, The role of the volume regulated anion channel (VRAC) in a model CNS neuronal cell line, CAD, was investigated. Methods:, Changes in cell volume following hypotonic challenges were measured using a video-imaging technique. The effect of the Cl, channel antagonists tamoxifen (10 ,m) and 4,4,-diisothiocyanatostilbene-2,2,-disulphonic acid (DIDS; 100 ,m) on regulatory volume decrease (RVD) were measured. The whole-cell voltage-clamp technique was used to characterize IClswell, the current underlying the VRAC. Results:, Using the video-imaging technique, CAD cells were found to swell and subsequently exhibit RVD when subjected to a sustained hypotonic challenge from 300 mOsmol kg,1 H2O to 210 mOsmol kg,1 H2O. In the presence of tamoxifen (10 ,m) or DIDS (100 ,m) RVD was abolished, suggesting a role for the VRAC. A hypotonic solution (230 mOsmol kg,1 H2O) evoked IClswell, an outwardly rectifying current displaying time-independent activation, which reversed upon return to isotonic conditions. The reversal potential (Erev) for IClswell was ,14.7 ± 1.4 mV, similar to the theoretical Erev for a selective Cl, conductance. IClswell was inhibited in the presence of DIDS (100 ,m) and tamoxifen (10 ,m), the DIDS inhibition being voltage dependent. Conclusions:, Osmotic swelling elicits an outwardly rectifying Cl, conductance in CAD cells. The IClswell observed in these cells is similar to that observed in other cells, and is likely to provide a pathway for the loss of Cl, which leads to water loss and RVD. As ischaemia, brain trauma, hypoxia and other brain pathologies can cause cell swelling, CAD cells represent a model cell line for the study of neuronal cell volume regulation. [source] Physico-biochemical parameters and protein profiles of sperm from beluga Huso husoJOURNAL OF APPLIED ICHTHYOLOGY, Issue 5 2010P. Li Summary Basic physico-biochemical parameters and protein profiles of sperm from beluga (Huso huso), have been evaluated. The results show a stable spermatozoan velocity (ranging from 136.23 ± 5.63 to 105.78 ± 5.27 ,ms,1) and motility during 2 min post activation, as well as a long duration of the overall spermatozoa motility period (up to 5 min). Mean values were determined for seminal plasma protein concentration (0.29 ± 0.16 mg ml,1), spermatozoa concentration (0.28 ± 0.27 × 109 spz ml,1), seminal plasma osmolality (51.33 ± 4.91 mOsmol kg,1), the pH (8.49 ± 0.01) and Na+ (18.97 ± 3.65 mm), K+ (2.83 ± 1.36 mm), Ca2+ (0.19 ± 0.06 mm), Mg2+ (0.49 ± 0.23 mm) and Cl, (6.33 ± 0.58 mm) concentrations. Moreover, in seminal plasma, five protein bands with molecular weights (MW) of 71, 49, 46, 34, 29 kDa were identified. In spermatozoa, about 100 spots with molecular weights varying from 26.5 to 107 kDa and iso-electric points ranging from 5 to 9.5 were found. The observed physiological and biochemical properties, together with protein patterns, should be considered for the development of methods for controlled reproduction and sperm cryopreservation for the highly endangered beluga sturgeon. [source] The current status of sperm cryopreservation of the endangered Probarbus jullieni (Sauvage) in MalaysiaJOURNAL OF APPLIED ICHTHYOLOGY, Issue 5 2010P. C. Chew Summary The objective of this study was to develop a cryopreservation method in Probarbus jullieni sperm, an endangered riverine fish species in Southeast Asia, including the optimization of an extender solution (14 extender formulations were tested) and selecting a cryoprotectant (five types of agents and methanol were used at concentrations (v/v) of 5, 7.5, 9, 10, 12, 15 and 20%). The semen to diluent ratios tested were as follow: 1 : 1, 1 : 2, 1 : 3, 1 : 4, 1 : 5, 1 : 7, 1 : 9, 1 : 14, 1 : 19, 1 : 24 and 1 : 49. Vapour exposure duration was set at 5, 10, 15 and 20 min while the distance between sample and liquid nitrogen (LN2) during the vapour exposure was designed at 3, 3.5, 4, 5 and 6 cm. Further, the time frame for thawing was set at 6, 7, 8, 10, 20 and 30 s. The optimum protocol was by using CF-HBSS (pH 7.5, osmolality 285 ± 10 mOsmol kg,1) in combination with methanol at 9% (v/v); sperm to diluents ratio between 1 : 3 to 1 : 5; vapour exposure for 5 min or 10 min, with samples placed at 3.5 cm or 4 cm above LN2 and thawing at 40°C for 7 s. The mean of pre-frozen and post-thaw sperm motility was 80.1 ± 13.6% (n = 43) and 49.6 ± 16.4% (n = 43) respectively. The reproductive characteristics of P. jullieni during its spawning season were addressed in present work. Cryopreserved sperm was found to have lower fertilization ability (4.2 ± 2.5%, n = 1050) and hatching rate (1.6 ± 1.2%, n = 1050) compared with fresh sperm (fertilization 77.7 ± 6.2%, n = 1050; hatching 64.7 ± 7.7%, n = 1050). The resulted problems and constraints encountered in the process of sperm cryopreservation of the species studied were also reported in this paper. [source] Sperm motility and seminal plasma characteristics in Barbus sharpeyi (Günther, 1874)AQUACULTURE RESEARCH, Issue 10 2010Sayyed Mohammad Hadi Alavi Abstract Spermatozoa concentration, ionic composition, osmolality, glucose and total protein contents of seminal plasma and sperm motility were determined in Barbus sharpeyi (Cyprinidae, Teleosotei). Spermatozoa concentration ranged from 9.77 to 20.20 × 109 spermatozoa mL,1. Osmolality (mOsmol kg,1) and ionic contents (mM L,1) of the seminal plasma were 274.5±9.0, 70.0±3.4 Na+, 28.8±0.9 K+, 101.7±3.1 Cl,, 0.9±0.1 Mg2+ and 2.1±0.1 Ca2+ respectively. Total protein and glucose were 5.3±0.2 g L,1 and 76.7±4.3 mM L,1 respectively. Sperm motility was initiated in a hypo-osmotic condition, composed of either an ionic (KCl or NaCl) or a non-ionic (sucrose) activation medium. Duration of sperm motility was very short: <2 min after activation in distilled water. Percentage of motile spermatozoa was significantly higher in an activation medium containing NaCl compared with that of distilled water. An activating medium containing NaCl or KCl higher than 150 mM or sucrose higher than 275 mM totally inhibited the activation of sperm motility. Immediately after sperm activation, wave(s) propagated along the flagellum, but waves were restricted to the proximal part of the flagellum (close to the head) at 1 min post activation. Studied characteristics in the present study were compared with those of other cyprinids for understanding inter-species differences. [source] Cryopreservation of silver barb Puntius gonionotus (Bleeker) spermatozoa: effect of extender composition, cryoprotective agents and freezing rate on their postthawing fertilization abilityAQUACULTURE RESEARCH, Issue 15 2008Padmanav Routray Abstract The effects of extender composition, cryoprotectant concentration and freezing and thawing on the fertilization efficiency of cryopreserved spermatozoa of Puntius gonionotus were evaluated. Computer-aided motility analysis of semen was conducted to check the suitability of spermatozoa for cryopreservation after mixing with different extenders and cryoprotective agents (CPAs). Extender-4 with an osmolality 260 mOsmol kg,1and pH 7.6 was used for the cryopreservation study. Among the CPAs, dimethyl sulphoxide (DMSO) was least toxic and more than 60% fertilization was achieved when used at 1.4 M at 0 °C for 10 and 30 min, whereas the toxicity of all CPAs to spermatozoa was evident when tested at 30 °C. Semen frozen at ,16 °C min,1 with 1.4 M DMSO showed 70% fertilization, which was significantly higher (P<0.05) than other freezing rates. Samples thawed at 35 °C water showed a fertilization rate comparable with that of fresh semen. Computer-assisted semen analysis of fresh and frozen semen after thawing showed variations in different types of motility in spermatozoa and in their class. There was no significant difference in motility before or after cryopreservation; however, significant differences could be observed in the average path velocity (VAP), straight line velocity (VSL) and curve linear velocity (VCL). Semen of silver barb could be cryopreserved with extender-4 by addition of 1.4 M DMSO to a final cryopreservation medium (MED 2) cooled at a rate of ,16 °C min,1, stored in liquid nitrogen (,196 °C) and utilized after thawing at 35±2 °C. [source] | ||||||||||