Molecular mechanism for human sperm chemotaxis mediated by progesterone.

Sperm chemotaxis is a chemical guiding mechanism that may orient spermatozoa to the egg surface. A picomolar concentration gradient of Progesterone (P), the main steroidal component secreted by the cumulus cells that surround the egg, attracts human spermatozoa. In order to elucidate the molecular mechanism of sperm chemotaxis mediated by P, we combine the application of different strategies: pharmacological inhibition of signaling molecules, measurements of the concentrations of second messengers and activation of the chemotactic signaling.

Progesterone sperm chemoattraction may be modulated by its corticosteroid-binding globulin carrier protein.

Progesterone, the main steroidal component secreted by the cumulus cells that surround the egg, chemotactically guides human spermatozoa. The aim of this work was to evaluate whether the carrier protein corticosteroid-binding globulin also participates in the sperm P chemotactic response. By means of videomicroscopy and image analysis, we observed that corticosteroid-binding globulin modulates the chemotactic activity of P, when a solution of corticosteroid-binding globulin + P is at the nanomolar range.

Molecular glass wool filtration as a new tool for sperm preparation.

Background: Magnetic-activated cell sorting (MACS) using annexin V-conjugated microbeads in a liquid phase eliminates apoptotic spermatozoa based on the externalization of phosphatidylserine (EPS) residues. The procedure allows the enrichment of a sperm population free of apoptosis markers, giving higher fertilization potential. Our aim was to determine if the annexin V binding principle can be transferred onto a glass wool filter system in order to produce a solid phase filter.

Progesterone at the picomolar range is a chemoattractant for mammalian spermatozoa.

By means of a videomicroscopy system and a computer image analysis, we performed chemotaxis assays to detect true chemotaxis in human spermatozoa, in parallel to immunohistochemistry detection of progesterone inside the cumulus cells. Progesterone indeed chemotactically guides mammalian spermatozoa at very low hormone concentrations, and the cumulus oophorus could be a potential place for sperm chemotaxis mediated by progesterone in vivo.

Influence of reactive oxygen species produced by activated leukocytes at the level of apoptosis in mature human spermatozoa.

Human spermatozoa incubated with polymorphonuclear leukocytes and Escherichia coli showed a significant increase in the annexin V binding (P<.05). This increase was similar to that obtained when spermatozoa were incubated with polymorphonuclear leukocytes activated by phorbol-12-myristate-13-acetate.

[Determination of peroxidase positive cells in semen: is it a secure parameter for the diagnosis of silent genital infections?].

Background: The presence of leukocytes, detected by peroxidase test in semen, can be a good indicator of infections in the male genital tract. Peroxidase positive cells have been positively correlated with elevated values of elastase, one of the major proteases liberated by granulocytes at the inflammation place. However, seminal granulocytes may not be adequately detected by the peroxidase test in comparison with immunological methods.

Expression and location of the bradykinin B2 receptor in rat testis.

To investigate the possible role of the local tissue kallikrein-kinin system in spermatogenesis, we analyzed gene expression and cellular distribution of the bradykinin subtype-2 receptor (B(2) receptor) in the rat testis. Reverse transcription-polymerase chain reaction revealed B(2) receptor expression in testis and primary cultures of Sertoli cells and peritubular cells isolated from immature and mature rats. In situ hybridization of the B(2)-receptor mRNA showed intense labeling of cells on the base of the seminiferous tubule, whereas the autoradiographic signals gradually decreased toward the lumen.

[Idiopathic endometrial decidual reaction in a woman in postmenopause: immunocytochemical evaluation of estrogen and progesterone receptors and its corticoid binding globulin].

Endometrial decidual reaction in postmenopausal women without an evident exogenous or endogenous progesterone stimulus, is uncommon. The morphological findings are decidual transformation of the endometrial stroma, necrosis, cellular pleomorphism and in some cases hyperplastic glands that exhibit focal atypia raising the possibility of malignancy. We report the case of a 55 years old woman with an idiopathic endometrial decidual reaction.