Regulation of apparent viscosity and O transfer coefficient by osmotic pressure in cell suspensions of Panax notoginseng

As the dry weight to fresh weight ratio of Panax notoginseng cells is related to the medium sugar concentration, the osmotic pressure can be increased by adding glucose to change cells' water content. When the apparent viscosity was decreased from 80.1 to 10 cp the surface O transfer coefficient (K a) increased from 4.80 to 5.68 h by adding 1.23 g glucose to 50 ml culture medium after 24 h.     

Short- and long-term, salinity-induced modulation of V-ATPase activity in the posterior gills of the true freshwater crab, Dilocarcinus pagei (Brachyura, Trichodactylidae)

To better understand the biochemical mechanisms underlying anisosmotic extracellular regulation in the freshwater Brachyura, we kinetically characterized the V-ATPase from the posterior gills of Dilocarcinus pagei, acclimated for 10days to salinities up to 21‰. Specific activity was highest in fresh water (26.5±2.1U mg(-1)), decreasing in 5‰ to 21‰, attaining 3-fold less at 15‰. Apparent affinities for ATP and Mg(2+) respectively increased 3.2- and 2-fold at 10‰, suggesting expression of different isoenzymes. In a 240-h time-course study of exposure to 21‰, maximum specific activity decreased 2.5- to 4-fold within 1 to 24h while apparent affinities for ATP and Mg(2+) respectively increased by 12-fold within 24h and 2.4-fold after 1h, unchanged thereafter. K(I) for bafilomycin A(1) decreased 150-fold after 1h, remaining constant up to 120h. This is the first kinetic analysis of V-ATPase specific activity in crustacean gills during salinity acclimation. Our findings indicate active gill Cl(-) uptake by D. pagei in fresh water, and short- and long-term down-regulation of V-ATPase-driven ion uptake processes during salinity exposure, aiding in comprehension of the biochemical adaptations underpinning the establishment of the Brachyura in fresh water.     

Plasma and pituitary prolactin levels in rainbow trout during adaptation to different salinities

The development of a highly specific radioimmunoassay for salmonid prolactin (PRL) using chinook salmon PRL allowed us to study plasma and pituitary PRL profiles in large sedentary rainbow trout (Salmo gairdneri) transferred from fresh water to seawater and vice versa. Plasma osmotic pressure and chloride levels were also measured for 3 weeks following change of salinity. Within 1 day after transfer to full seawater we observed a plasma PRL decrease, which stayed significantly lower (3-5 ng/ml) than the fresh water control group (10-15 ng/ml) during the entire experiment. Pituitary PRL content showed an initial abrupt increase, but after 3 weeks in seawater pituitary PRL content had decreased to the same level as in the fresh water control group. On the contrary, transfer from seawater to fresh water was followed within 1 day by a rise in plasma PRL levels, which stayed high (10-15 ng/ml) after 3 weeks in fresh water. Simultaneously, pituitary PRL content decreased significantly. These results may indicate an important role of PRL in fresh water adaptation of sedentary rainbow trout.     

Plasma and Tissue Levels of Trimethoprim in The Rainbow Trout,Salmo Gairdneri,After Absorption From Fresh and Salt Water

This is a comparative study of uptake of trimethoprim from 1) fresh water, 2) salt water after 7 days of adaption and 3) salt water without previous adaptation. The rate and extent of absorption were found to vary significantly. The salt water adapted group reached a plasma concentration of approx. 1 µg/ml after 10 h, the unadapted salt water group after 24 to 48 h and the fresh water group did not reach this concentration. The results are discussed in relation to the non-ionic diffusion theory and to the alterations taking place in euryhaline species of fish during adaptation to salt water.     

Glycoproteins histochemistry of the gills of Odontesthes bonariensis (Teleostei, Atherinopsidae)

The histochemistry of glycoproteins (GP) in the mucous cells of the gills of the silverside Odontesthes bonariensis was identified with: (1) oxidizable vicinal diols; (2) sialic acid and some of their chain variants, carbon 7 ((7) C), carbon 8 ((8) C) or carbon 9 ((9) C); (3) sialic acid residues without O-acyl substitution and with O-acyl substitution at (7) C, (8) C or (9) C; (4) carboxyl groups and (5) sulphate groups. A battery of seven biotinylated lectins allowed GPs sugar residues to be distinguished. Mucous cells showed the presence of neutral, sulphated and sialylated GPs. Dolichos biflorus agglutinin (DBA) and Glycine max agglutinin (SBA) showed strong positive staining; Arachis hypogaea agglutinin (PNA), Ricinus communis agglutinin-I (RCA-I) and Triticum vulgaris agglutinin (WGA) showed moderate staining, while Ulex europaeus agglutinin-I (UEA-I) was completely negative.     

Cellular responses in the skin of the trout (Oncorhynchus mykiss) exposed to temperature elevation

The skin of rainbow trout was examined at the ultrastructural and cytochemical level after a 3–h exposure to an elevation of the water temperature, from 15 to 22° C. Within 3 h, the thickness of the epidermis had significantly ( P <0·05) decreased when compared to control fish. After 24 h it was restored, and from day 4 onwards even increased above control levels. The thickening of the epidermis was associated with appearance of many mitotic cells, not observed in control fish. Within 24 h many apoptotic epidermal cells were found, indicating enhanced ageing of the cells. Filament cells from the outer epidermal layers synthesized vesicles with peroxidasc activity within 3 h after temperature elevation. This enzyme was found also in apoptotic as well as in necrotic filament cells. Mucous cells became elongated and their mucosomes displayed peroxidase activity. Occasionally electrondense, probably serous, mucosomes appeared. In the epidermis rodlet cells were found. Both epideimis and dermis, became invaded by many lymphocytes and macrophages. The latter contained vesicles with peroxidase activity. Pigment–containing cytoplasmic extensions of melanocytes penetrated the epidermis while iridocytes disappeared from the dermis. The synthetic activity of dermal fibroblasts was stimulated. These results show that a moderate temperature elevation has pronounced and prolonged effects on the skin of the exposed fish. The effects are to a high extent comparable with those of stressors such as heavy metals, acid water or wounding.     

Effects of acute fresh water exposure on water flux rates and osmotic responses in Kemp's ridley sea turtles (Lepidochelys kempi)

Water flux rates and osmotic responses of Kemp's Ridley sea turtles (Lepidochelys kempi) acutely exposed to fresh water were quantified. Salt-water adapted turtles were exposed to fresh water for 4 d before being returned to salt water. During the initial salt water phase, absolute and relative water flux rates were 1.2+/-0.1 l d(-1) and 123.0+/-6.8 ml kg(-1) d(-1), respectively. When turtles were exposed to fresh water, rates increased by approximately 30%. Upon return to salt water, rates decreased to original levels. Plasma osmolality, Na(+), K(+), and Cl(-) decreased during exposure to fresh water, and subsequently increased during the return to salt water. The Na(+):K(+) ratio was elevated during the fresh water phase and subsequently decreased upon return to salt water. Aldosterone and corticosterone were not altered during exposure to fresh water. Elevated water flux rates during fresh water exposure reflected an increase in water consumption, resulting in a decrease in ionic and osmotic concentrations. The lack of a change in adrenocorticoids to acute fresh water exposure suggests that adrenal responsiveness to an hypo-osmotic environment may be delayed in marine turtles when compared to marine mammals.     

Inhibition of Ca2+ uptake in freshwater carp, Cyprinus carpio, during short-term exposure to aluminum.

In carp exposed to pH 5.2 in fresh water, the Ca2+ influx from the water is reduced by 31% when compared to fish in water of neutral pH. At pH 5.2, the Ca2+ influx but not Na+ uptake is decreased by aluminum (Al). Al reduces Ca2+ influx dose-dependently: a maximum 55% reduction was observed after 1-2 h exposure to 200 micrograms.1(-1) (7.4 microM) Al. Branchial Ca2+ efflux is less sensitive to Al and affected only by exposure for more than 1 h to high Al concentrations. Na+ influx is not affected by concentrations Al up to 400 micrograms.1(-1). Na+ efflux, similarly to Ca2+ efflux, increased when fish were exposed for more than 1 h to 400 micrograms.1(-1) Al.     

DECREASE IN DYNAMIC VISCOSITY AND AVERAGE MOLECULAR WEIGHT OF ALGINATE FROM LAMINARIA DIGITATA DURING ALKALINE EXTRACTION1

Alginates are natural polysaccharides that are extracted from brown seaweeds and widely used for their rheological properties. The central step in the extraction protocol used in the alginate industry is the alkaline extraction, which requires several hours. In this study, a significant decrease in alginate dynamic viscosity was observed after 2 h of alkaline treatment. Intrinsic viscosity and average molecular weight of alginates from alkaline extractions 1–4 h in duration were determined, indicating depolymerization of alginates: average molecular weight decreased significantly during the extraction, falling by a factor of 5 between 1 and 4 h of extraction. These results suggested that reducing extraction time could enable preserving the rheological properties of the extracted alginates.     

High viscosity and anisotropy characterize the cytoplasm of fungal dormant stress-resistant spores

Ascospores of the fungus Talaromyces macrosporus are dormant and extremely stress resistant, whereas fungal conidia--the main airborne vehicles of distribution--are not. Here, physical parameters of the cytoplasm of these types of spores were compared. Cytoplasmic viscosity and level of anisotropy as judged by spin probe studies (electron spin resonance) were extremely high in dormant ascospores and during early germination and decreased only partly after trehalose degradation and glucose efflux. Upon prosilition (ejection of the spore), these parameters fell sharply to values characteristic of vegetative cells. These changes occurred without major volume changes that suggest dramatic changes in cytoplasmic organization. Azide reversibly inhibited prosilition as well as the decline in cytoplasmic parameters. No organelle structures were observed in etched, cryoplaned specimens of ascospores by low-temperature scanning electron microscopy (LTSEM), confirming the high cytoplasmic viscosity. However, cell structures became visible upon prosilition, indicating reduced viscosity. The viscosity of fresh conidia of different Penicillium species was lower, namely, 3.5 to 4.8 cP, than that of ascospores, near 15 cP. In addition the level of anisotropic motion was markedly lower in these cells (h(0)/h(+1) = 1.16 versus 1.4). This was confirmed by LTSEM images showing cell structures. The decline of cytoplasmic viscosity in conidia during germination was linked with a gradual increase in cell volume. These data show that mechanisms of cytoplasm conservation during germination differ markedly between ascospores and conidia.     

Disruption of leaves and initial extraction of wildtype CPMV virus as a basis for producing vaccines from plants.

Wildtype cowpea mosaic virus (CPMV) was extracted from fresh and frozen plant material by methods suitable for large-scale application. Deep freezing, crushing, and thawing in water or buffers gave 0.6+/-0.2 mg g(-1) of virus after up to 24 h. Release from sliced fresh leaves was lower at 0.14+/-0.03 mg g(-1). Homogenisation of frozen leaves for 1 min increased yield to a maximum, on average of 3.5 mg g(-1) but varying between batches from 2.2 to 4.8 mg g(-1) virus Long term storage at -80 degrees C increased subsequent yield by 2 mg g(-1) per year on average; the maximum was 10.4+/-1.9 mg g(-1) (665 days storage). Within a batch, similar yields were obtained between individual fresh plants, and from frozen versus fresh leaves. After homogenisation for 1 min, 90% of debris particles were smaller than 12 microm, half under 5 microm and 10% less than 1 microm. Homogenate (4% dry weight) was rheologically complex, exhibiting shear thinning with hysteresis at low shear rates which bears on subsequent processing. At shear rates above 200 s(-1), its apparent viscosity was 0.02 N s m(-2).     

Blood osmolality shift in juvenile red drum, Sciaenops ocellatus L. exposed to fresh water

Juvenile red drum, Sciaenops ocellatus , measuring 40–49 mm s.l. tolerated abrupt transfer from 28%osalinity sea water to fresh water (< l%o). A significant shift in blood osmolality from a level of about 350 mosmol l⁻¹ in sea water to a new level of about 311 mosmol l⁻¹ was experienced by fish after 48 h in fresh water. The shift was followed by a slight reduction in blood osmolality to a sustained level of 300 mosmol l⁻¹ after 96 h exposure to fresh water. The overall effect of increased environmental calcium on blood osmotic pressure of young red drum was not significant at the level tested.     

Microbial production of low molecular weight hyaluronic acid by adding hydrogen peroxide and ascorbate in batch culture of Streptococcus zooepidemicus

Microbial production of low molecular weight hyaluronic acid (HA) by the addition of hydrogen peroxide and ascorbate during the batch culture of Streptococcus zooepidemicus was investigated. Hydrogen peroxide (1.0 mmol/g HA) and ascorbate (0.5 mmol/g HA) were added at 8h and 12h to degrade HA. With the redox depolymerization of HA, the HA molecular weight decreased from 1,300 kDa for the control to 80 kDa, and the average broth viscosity during 8-16 h decreased from 360 mPa s for the control to 290 mPa s. The average oxygen mass transfer coefficient K(L)a increased from 10h(-1) for the control to 35 h(-1) and the average dissolved oxygen level increased from 1% of air saturation in the control to 10%. HA production increased from 5.0 g/L for the control to 6.5 g/L, and contributed to the increased redox potential and energy charge. This novel process not only significantly enhanced production of low molecular weight HA, but also improved purification efficiency due to a decreased broth viscosity. Low molecular weight HA finds applications in biomedical and healthcare fields.     

Alteration of blood hemorheologic properties during cerebral ischemia and reperfusion in rats

The cerebral ischemia and reperfusion rat model was employed in this experiment to study the rheological properties (i.e. viscosity, hematocrit, red blood cell deformability and thixotropic properties) of whole blood. The results of this study show that a significant relation exists between the duration of cerebral ischemia and reperfusion and the viscosity, hematocrit and thixotropic parameters of whole blood, but there is no significant influence on the deformability of RBC. Blood viscosity values declined gradually throughout the ischemia period, e.g., after 1h of ischemia, the values of whole blood viscosity under high, middle and low shear rates were 44, 28 and 23% lower than normal, respectively. Whereas after 1h of reperfusion, the values of viscosity increased rapidly to values 160, 57 and 41% higher than normal under the high, middle and low levels of shear rate, while the viscosity values after 12h of reperfusion tended to return to normal values. The values of hematocrit H and thixotropic parameter tau(0) and mu also gradually declined with the increase in the duration of ischemia, but increased significantly after 1h of reperfusion. The values of H, tau(0) and mu after 1h of reperfusion are significantly greater than that in the period of cerebral ischemia, the value of H, tau(0) is also higher than normal. With the increase in reperfusion time, H, tau(0) gradually returned to normal level, at the same time, mu also decreased.     

Cadmium-induced changes in epithelial cells of the rat stomach

The aim of this study was to determine the changes in the function and fine structure of the gastric mucosa following exposure to high cadmium (Cd) for 30 d in rats. In the present study, control antimals were fed with normal food and tap water and the remaining animals received Cd (15 ppm CdCl₂) in drinking water for the same period. Receiving Cd for 30 d increased the mean blood (p<0.01) and mucosa (p<0.001) Cd levels, while decreased mucus thickness, mucin content (p<0.01) significantly. Basal acid output fell significantly (p<0.01). Light and electron microscopic examination revealed the following: (1) Cd decreases the mean number of surface mucous, isthmic-neck, parietal cells (p<0.05) and chief cells (p<0.001) per unit from the control value and (2) in some cells of zymogenic unit, the Cd-induced alterations were characterized with dilated Golgi cisternae, focal enlarged endoplasmic reticulum, broken tubulovesicles, degenerated mitochondria, dense nuclei, as well as lysosomal structures. We concluded that Cd augments the elimination rate of zymogenic unit’s cells by increasing the alteration rate, and the reduced basal acid output, mucin content, and mucus thickness can be explained easily with the loss of zymogenic unit’s cell population.     

Changes in osmotic water permeability of the eel gills during seawater and freshwater adaptation

Summary Changes in osmotic water permeability of the isolated gills of the Japanese eel,Anguilla japonica were studied during transfer to seawater or to fresh water. The water permeability increased gradually during the course of seawater transfer and attained a maximal level after 2 weeks. The water permeability of the freshwater eel gills was reduced when calcium ions were added to the incubation medium at a concentration of 1 mM, where-as no effect of the ion was observed on the gills of the seawater-adapted eel even at a higher concentration (10 mM). In contrast to seawater transfer, the water permeability decreased to a low level almost immediately (3 h) after transfer from seawater to fresh water. The acute reduction of the water permeability was also seen in the gills of the hypophysectomized eel after transfer to fresh water.The gradual increase in the gill water permeability during seawater transfer is correlated with an increase in the number of chloride cells. In scanning electron microscopy, chloride cells of seawater-adapted eel gills exhibit a pit-like structure, which was larger than in the freshwater eel. On transfer from seawater to fresh water, the pit diameter became smaller within 6 h. Hypophysectomy did not affect the change in gill surface structures during transfer to fresh water. The junctions between the chloride cells of seawater eel gills are reported to be of the leaky type. The parallel change in osmotic water permeability and in pit size of the chloride cells during seawater or freshwater transfer or after hypophysectomy suggests that these cells could provide a major route of water as well as ion movement.This paper is a portion of a thesis presented to Hokkaido University by t. Ogasawara in partial fulfilment of the requirements for Doctor of Fisheries     

Arterial Po2, acid-base status, and red cell nucleoside triphosphates in rainbow trout transferred from fresh water to 20‰ sea water

Transfer of rainbow trout from fresh water to 20‰ sea water decreased dorsal aortic Po₂ from 90 to 60 mmHg within 1 h. Arterial Po₂ was depressed for 24 h before it returned to control values. The internal hypoxia rapidly reduced the red cell nucleoside triphosphate content, suggesting prompt regulation of blood O₂ affinity. The extracellular acid-base status changed towards a small mixed metabolic and respiratory acidosis.     

The effect of viscosity of semen diluents on motility of bull spermatozoa

The effect of egg yolk extender on semen viscosity and bull sperm motility of fresh and cooled or deep frozen semen was determined by a computer-assisted system. Viscosity of the extender was determined by flow time. Based on the sperm velocity (velocity of the average path), individual spermatozoon were classified into groups of progressively motile (>==30 microm/sec) and immotile (<10 microm/sec) spermatozoa. The average velocity of progressively motile spermatozoa (VPM), the velocity of linear progressively motile spermatozoa (VLP) and the percentage of linear swimming spermatozoa (LIN) were evaluated. The addition of 10, 20 or 30% egg yolk to Tris buffer (pH 6.5) resulted in a linear decrease of VPM and a decrease in the percentage of progressively motile spermatozoa, but it increased the relative rate of LIN in fresh diluted semen. Increasing the levels of egg yolk in the diluent resulted in higher viscosity. The VLP was significantly higher than the VPM. In refrigerated or frozen semen samples, extender with 30 and 20% egg yolk had a similar effect on the VPM but not on the percentage of progressively motile sperm cells. Freezing of egg yolk (30%) extender to -20 degrees C resulted in a significant increased flow time and higher viscosity. Dilution of semen samples with high viscosity extender decreased the VPM in fresh and chilled semen. Freezing semen of high viscosity extender with glycerol had no apparent effect on the percentage of progressively motile spermatozoa compared with that of non-glycerinated egg yolk extender. The results suggest that different concentrations of egg yolk in the extender can influence the parameters of semen viscosity and sperm motility evaluated by a computer-assisted system.     

Cellular responses in the skin of rainbow trout (Oncorhynchus mykiss) exposed to Rhine water

Trout, Oncorhynchus mykiss , were exposed to water from the Rhine for 24 days and their skin examined by light and electron microscopy. Relative to control fish mitotic figures were common and seen throughout the epidermis. Pavement cells in fish exposed to Rhine water contained significantly more secretory vesicles than control fish. Necrotic pavement cells were apparent after 24 h, and apoptotic cells from day 4 on. Mucous secretion was intense and the differentiation of mucous cells was stimulated. Some of these cells synthesized mucus of high electron density, probably of a serous composition. Leucocytes invaded the dermis and epidermis, and towards the end of the experiment many apoptotic and necrotic lymphocytes were found. In the dermis fibroblasts were abundant and actively producing collagen. Pigment containing cytoplasmic extensions of melanocytes penetrated into the epidermis. After 14 and 24 days of exposure many pigment cells, melanocytes, iridocytes and xanthocytes became apoptotic. Most of these changes are known from fish exposed to heavy metals, acid water or other stressful treatments, indicating that exposure to Rhine water is a stressful experience for trout.     

五唇兰对PEG模拟的干旱胁迫响应研究

为了解干旱对五唇兰(Phalaenopsis pulcherrima)生长的影响,以聚乙二醇(PEG)溶液模拟干旱胁迫,对其叶片的光合色素、渗透调节物质和非结构碳水化合物(NSC)含量变化进行研究。结果表明,随着PEG浓度增加,五唇兰植株含水量和鲜质量逐渐下降,以PEG为13.75%～14.84%时最显著。PEG处理显著降低叶片的叶绿素a和b含量。随着植株含水量的降低,叶片可溶性蛋白、淀粉(St)含量均呈下降趋势,可溶性糖(SS)含量、NSC和SS/St均呈先升后降的趋势。因此,干旱胁迫会影响五唇兰植株的含水量和光合产物的积累;在较低程度干旱胁迫下,可溶性糖在抗旱响应中发挥主要作用;随着干旱胁迫程度加深,五唇兰的生理代谢受到严重影响。