background: while traditional semen parameters are of significant clinical value, total fertilization failure in ivf cycles is not uncommon. sperm function testing such as; hamster egg penetration test has severed limitations as a clinical test. the aim of this study was to evaluate the predictive value of semen parameters by using of intracellular calcium [ca2+]i increase in response to proges...

The concentration of intracellular Ca2+ [( Ca2+]i) was measured in dissociated bovine parathyroid cells loaded with quin-2 or fura-2. In quin-2-loaded cells, increases in the concentration of extracellular Ca2+ elicited slow, monophasic increases in [Ca2+]i, whereas in fura-2-loaded cells, extracellular Ca2+ evoked rapid, transient increases which were followed by lower, yet sustained increases...

The intracellular calcium concentration ([Ca2+])i of astrocytes within rat hippocampal slices was measured during simultaneous hypoxia and hypoglycemia to examine the early intracellular signaling events induced by this in vitro model of ischemia. Hypoxia-hypoglycemia for 3.3-7.5 min evoked [Ca2+]i increases in astrocytes iontophoretically loaded with calcium orange (11/14 slices; 2.5 min to pe...

Human neutrophils exhibit multiple increases in cytosolic free calcium concentration [( Ca2+]i) spontaneously and in response to the chemoattractant N-formyl-L-methionyl-L-leucyl-L-phenylalanine (Jaconi, M. E. E., R. W. Rivest, W. Schlegel, C. B. Wollheim, D. Pittet, and P. D. Lew. 1988. J. Biol. Chem. 263:10557-10560). The function of these repetitive increases in [Ca2+]i, as well as the role ...

This study used imaging and electrophysiological techniques in salamander retinal slices to correlate Ca2+ and Cl- levels in rods and thus test the hypothesis of a feedback interaction between Ca2+- and Ca2+-activated Cl- channels whereby Cl- efflux through Cl- channels can inhibit Ca2+ channels. Increasing [K+]o levels produced a concentration-dependent depolarization of rods accompanied by in...

Intracellular calcium concentration ([Ca2+]i)-dependent activation of myosin light chain kinase and its phosphorylation of the 20-kd light chain of myosin is generally considered the primary mechanism responsible for regulation of contractile force in arterial smooth muscle. However, recent data suggest that the relation between [Ca2+]i and myosin light chain phosphorylation is variable and dep...

Previous work (Babcock, D. F., Rufo, G. A., and Lardy, H.A. (1983) Proc. Natl. Acad. Sci. U.S.A. 80, 1327-1331) established that increased cytosolic pH (pHi) promotes metabolic and swimming activity of bull sperm and that intracellular alkalinization results from elevated extracellular K+, presumably as a consequence of membrane depolarization. The present studies show that a persistent but rev...

in the mammalian, there are three ncx genes (ncx1, ncx2, ncx3), which their three proteins are differentially expressed in distinct regions of the central nervous system, where they might underlie different physiological and pathophysiological functions. ncx is a nine-transmembrane protein which is distributed in the brain widely. ncx operates in a bidirectional way, and exchanges ca2+ and na+ ...

Slices of somatosensory cortex taken from immature rats on postnatal day (P)7-14 were labeled with fura-2. Intracellular Ca2+ concentration ([Ca2+]i) was monitored in identified pyramidal cells as the ratio of fluorescence intensities (RF340/F380) during oxygen-glucose deprivation. The RF340/F380 ([Ca2+]i) of individual pyramidal cells was monitored in each of the cortical layers II-VI simultan...

The hypothesis that signal transduction mediated by platelet-derived growth factor (PDGF) and angiotensin II (Ang II) is altered in vascular smooth muscle (VSM) cells from the spontaneously hypertensive rat (SHR) was tested by measuring changes in the cytosolic free calcium concentration ([Ca2+]i). [Ca2+]i was measured in cultured aortic smooth muscle cells from SHRs and Wistar-Kyoto (WKY) norm...