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In order to examine the role of osmotic forces in degranulation, the effects of solutes and osmolality on granule secretion were explored using both FMLP-stimulated, intact neutrophils and Ca2+-stimulated, permeabilized cells. We employed a HEPES-based buffer system which was supplemented with: a) permeant (KCl or NaCl) or impermeant (Na-isethionate or choline-Cl) ions, or b) permeant (urea) or...

The resting potential of identified cells (Parker cells) in the abdominal ganglion of Elysia chlorotica (Gould) depolarizes by about 30 mV in response to a 50% reduction in osmolality and returns to the original potential in 20 min. Cell volume recovery requires approximately 2 h. Thus, recovery of the resting potential is not dependent on recovery of cell volume. The hypo-osmotic depolarizatio...

When third-stage larvae of Pseudoterranova decipiens maintained at 5 degrees C are placed in either 40% artificial sea water (ASW, iso-osmotic) or 15% ASW (hypo-osmotic) and weighed once at 0 h and again at 24 h, they neither lose nor gain weight, and the osmotic pressure (OP) of their pseudocoelomic fluid (PCF) remains unchanged. In contrast, when worms are weighed six additional times during ...

Abstract The aim of this study was to determine the effects gallic acid (GA) on frozen-thawed goat spermatozoa. Four Honamli bucks were used at their breeding season, and ejaculates collected by an electroejaculator. Mixed semen divided into following four groups: control (0 mM), low (L; 1 medium (M; 2 high (H; 4 mM) concentration GA. All groups frozen thawed in a water bath for spermatological...

Fertility is dependent on a complex set of events, involving both male and female components. Normal sperm function involves many steps, including motility, capacitation, acrosome reactivity and, ultimately, fertilization of the oocyte. While male fertility is most often assessed by means of gross semen parameters, infertility may also be caused by abnormal sperm function, and only by performin...

The aim of current study was to investigate the changes in the quality parameters of Holstein bull semen during the heat stress and the effect of feeding a source of omega-3 fatty acids in this period. Samples were obtained from 19 Holstein bulls during the expected time of heat stress in Iran (June to September 2009). Control group (n=10) were fed a standard concentrate feed while treatment gr...

In hepatocyte cultures, insulin stimulates cellular accumulation of K+, partly (approximately 20%) by net replacement of cell Na+, but largely (approximately 80%) by increasing the cell K++Na+ content, with a consequent increase in cell volume. An increase in cation content occurred within 5 min of exposure to insulin and was not secondary to metabolic changes. Insulin also increased the cation...

A hypo-osmotic swelling test using TALP-HEPES medium over a range of 50 to 300 mOsm/kg was applied to sperm from domestic and endangered species. Maximal responses of curling of the sperm tails were seen over a range of osmolalities for epididymal sperm from the pig (100 mOsm/kg), hamadryas baboon (range 50-125 mOsm/kg), and central rock rat (range 50-100 mOsm/kg), and the ejaculated sperm from...