Cytochemical localization of membrane-bound Mg2+-dependent ATPase activity in guinea pig sperm head before and during the acrosome reaction

1986 ◽  
Vol 13 (4) ◽  
pp. 271-280 ◽  
Author(s):  
Noriko Usui ◽  
Ryuzo Yanagimachi
Keyword(s):  
Guinea Pig ◽  
Atpase Activity ◽  
Acrosome Reaction ◽  
Sperm Head ◽  
Cytochemical Localization ◽  
Dependent Atpase ◽  
Membrane Bound

scholarly journals Cytochemical localization of ecto-ATPases in rat neurohypophysis.

1996 ◽  
Vol 44 (2) ◽  
pp. 103-111 ◽  
Author(s):  
S Thirion ◽  
J D Troadec ◽  
G Nicaise
Keyword(s):  
Electron Microscopy ◽  
Plasma Membrane ◽  
Atpase Activity ◽  
Outer Surface ◽  
Nerve Endings ◽  
Glutaraldehyde Fixation ◽  
Cytochemical Localization ◽  
Cytochemical Method ◽  
Ca Pump ◽  
Dependent Atpase

We studied the distribution of Ca(2+)- or Mg(2+)-dependent ATPase activity in rat neurohypophysis using the lead cytochemical method of Ando et al. In electron microscopy, precipitates were found lining the outer surface of the plasma membrane surrounding nerve endings and pituicytes. These precipitates were believed to represent the activity of ecto-ATPases (as opposed to Ca pump ATPases) for the following reasons: there was equal activation by Ca2+ in the absence of Mg2+ or Mg2+ in the absence of Ca2+; the effects of the two ions were not additive; there was activation by ATP or GTP; and there was resistance to glutaraldehyde fixation, to high (10 mM) Ca2+ concentrations, and to various inhibitors such as NEM, vanadate, oligomycin, quercetin, p-chloromercuribenzoate, ouabain, and levamisole. Cytosolic activity observed in certain nerve endings in the same conditions of incubation but more sensitive to NEM is also described and discussed.

Effect of locally applied drugs on the pH of luminal fluid in the endolymphatic sac of guinea pig

2000 ◽  
Vol 279 (5) ◽  
pp. R1695-R1700 ◽  
Author(s):  
Vincent Couloigner ◽  
Marie Teixeira ◽  
Philippe Hulin ◽  
Olivier Sterkers ◽  
Maurice Bichara ◽  
...  
Keyword(s):  
Carbonic Anhydrase ◽  
Guinea Pig ◽  
Atpase Activity ◽  
Acid Secretion ◽  
Ph Sensitive ◽  
Endolymphatic Sac ◽  
Transport Systems ◽  
Membrane Bound ◽  
The Relationship

The aim of the present work was to assess the effect of various drugs applied locally on the pH of the luminal fluid (pHlum) in guinea pig endolymphatic sac. pHlum and transepithelial potential, when measured in vivo by means of double-barrelled pH-sensitive microelectrodes, were 7.06 ± 0.08 and +6.1 ± 0.34 mV (mean ± SE; n = 84), respectively, which is consistent with a net acid secretion in the luminal fluid of the endolymphatic sac. Bafilomycin and acetazolamide increased and decreased, respectively, pHlum. Amiloride, ethylisopropylamiloride, ouabain, and Schering 28080 had no effect on pHlum. Results obtained with inhibitors of anionic transport systems were inconclusive; e.g., DIDS reduced pHlum, whereas neither SITS nor triflocin had any effect. We conclude that bafilomycin-sensitive H+-ATPase activity accounts for the transepithelial acid gradient measured in the endolymphatic sac and that intracellular and membrane-bound carbonic anhydrase probably participates in regulating endolymphatic sac pHlum. The relationship between acid pH, endolymph volume, and Ménière's disease remains to be further investigated.

The histochemical localization of acrosin in guinea-pig sperm after the acrosome reaction

1978 ◽  
Vol 32 (1) ◽  
pp. 177-184
Author(s):  
D.P. Green ◽  
A.R. Hockaday
Keyword(s):  
Electron Microscopy ◽  
Guinea Pig ◽  
Acrosome Reaction ◽  
Sperm Head ◽  
Ultrastructural Evidence ◽  
Acrosomal Membrane ◽  
Sperm Penetration ◽  
Inner Acrosomal Membrane ◽  
Dense Marker

The protease acrosin is widely considered to be an essential component of a zona lysin which enables sperm to penetrate the zona pellucida of the egg. Sperm form a characteristic penetration slit little wider than the sperm head itself and this has long suggested that any zona lysin is attached to the sperm surface after an acrosome reaction. This paper provides the first ultrastructural evidence that this is the case. The protein acrosin inhibitor, Kunitz soybean trypsin inhibitor, has been covalently attached to the electron-dense marker, ferritin, and the conjugate incubated with guinea-pig sperm which have undergone an A23187-induced acrosome reaction. Electron microscopy shows that ferritin is distributed unevenly over the outer surface of the newly exposed inner acrosomal membrane but does not extend to the equatorial segment. This is further evidence that acrosin can be considered as a candidate for the role of zona lysin. The mechanism of sperm penetration of the zona is discussed in the light of these observations.

A High Resolution Cytochemical Study of Nuclear ATPase in Human Spermatozoa

1975 ◽  
Vol 33 ◽  
pp. 594-595
Author(s):  
A. Sosa ◽  
L. Calzada
Keyword(s):  
High Resolution ◽  
Atpase Activity ◽  
Nuclear Membrane ◽  
Human Sperm ◽  
Sperm Nucleus ◽  
Human Spermatozoa ◽  
Cytochemical Study ◽  
Membrane Bound ◽  
Sperm Nuclei ◽  
Interchromatin Space

The dependence of nuclear metabolism on the function of the nuclear membrane is not well understood. Whether or not the function of the nuclear membrane is partial or totally responsible of the repressed template activity of human sperm nucleus has not at present been elucidated. One of the membrane-bound enzymatic activities which is concerned with the mechanisms whereby substances are thought to cross cell membranes is adenosintriphosphatase (ATPase). This prompted its characterization and distribution by high resolution photogrammetry on isolated human sperm nuclei. Isolated human spermatozoa nuclei were obtained as previously described. ATPase activity was demonstrated by the method of Wachstein and Meisel modified by Marchesi and Palade. ATPase activity was identified as dense and irregularly distributed granules confined to the internal leaflet of the nuclear membrane. Within the nucleus the appearance of the reaction product occurs as homogenous and dense precipitates in the interchromatin space.

Structural insights into the transient closed conformation and pH dependent ATPase activity of S.Typhi GyraseB N- terminal domain

2021 ◽  
Vol 701 ◽  
pp. 108786
Author(s):  
Deepali Gupta ◽  
Pragya Tiwari ◽  
Md Anzarul Haque ◽  
Ekta Sachdeva ◽  
Md Imtaiyaz Hassan ◽  
...  
Keyword(s):  
Atpase Activity ◽  
Closed Conformation ◽  
Terminal Domain ◽  
Dependent Atpase ◽  
Ph Dependent ◽  
Structural Insights
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