Molecular and binding characteristics of IP3 receptors in bovine spermatozoa.

We have shown the presence of inositol 1,4,5-triphosphate (IP3) receptors in bovine spermatozoa. These receptors are mainly localized and functionally associated with the acrosome region. Molecular characterization of these bovine IP3 receptors has shown that the functional size of the IP3 binding domain is a protein of 66+/-2 kDa, in agreement with the size of both bovine adrenal cortex and bovine adrenal medullar chromaffin cells IP3 receptors.

CD26 and adenosine deaminase interaction: its role in the fusion between horse membrane vesicles and spermatozoa.

Membrane vesicles of horse seminal plasma present at their surface a highly specific serine-type protease, dipeptidyl peptidase IV/CD26, a surface antigen known to characterize human prostasomes. Horse sperm cells expressed at their surface A(1) adenosine receptors (A(1)AR) and ecto-adenosine deaminase (ecto-ADA), both detected by immunoblot analysis, whereas CD26 was visualized at the equatorial segment by immunofluorescence microscopy. In addition to CD26, horse membrane vesicles showed ecto-ADA.

Rabbit spermatozoa: a model system for studying ATP homeostasis and motility.

This paper studies the adenosine triphosphate (ATP) homeostasis and the motility parameters of rabbit spermatozoa. Rabbit sperm, collected by artificial vagina, were studied in various buffer systems to determine motility over time. Sperms were also extracted to measure enzyme activity.

Occurrence of prostasome-like membrane vesicles in equine seminal plasma.

Equine seminal plasma was shown to contain membrane vesicles that are similar to the well characterized prostasomes in human seminal plasma. Determination of nucleoside and nucleotide concentrations of these particles have shown that ATP, ADP and adenosine are the main components of the nucleotidic pool. 5' nucleotidase, endopeptidase and dipeptidyl peptidase i.