Concentrations of the intracellular Ca(2+)-mediator calmodulin (CaM), were measured by radioimmunoassay during heparin-induced capacitation of bull spermatozoa. Heparin reduced sperm CaM concentrations in a dose-dependent manner corresponding with an increase in in-vitro fertilization rates. Such reductions were observed after heparin treatment for 4-6 h, which is in agreement with the length of the capacitation period in bulls and was concomitant with an increase in CaM concentration in the incubation medium, suggesting translocation of CaM from the spermatozoa to the surrounding milieu. This CaM translocation was inhibited partly by the protease inhibitor benzamidine, suggesting a role for the sperm protease in this process.
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http://dx.doi.org/10.1530/jrf.0.0940023 | DOI Listing |
Reprod Domest Anim
June 2022
College of Animal Science and Technology, Gansu Agricultural University, Lanzhou, China.
Our goal was to investigate heparin-induced capacitation of frozen-thawed yak sperm and to assess the effects of caffeine or ouabain supplementation with heparin on sperm capacitation. Sperm were incubated with varying heparin concentrations, namely 0, 12.5, 25, 50 and 100 μg/ml, for 0, 15, 30 and 60 min.
View Article and Find Full Text PDFAnim Reprod
November 2019
Universidade Estadual do Norte Fluminense Darcy Ribeiro - UENF, Laboratório de Engenharia Agrícola, Campos dos Goytacazes, RJ, Brasil.
Theriogenology
December 2018
Universidad de Buenos Aires, Facultad de Ciencias Veterinarias, Instituto de Investigación y Tecnología en Reproducción Animal (INITRA), Unidad Ejecutora de Investigaciones en Producción Animal UBA-CONICET (INPA), Cátedra de Química Biológica, Av. Chorroarín 280 (1427), Ciudad Autónoma de Buenos Aires, Argentina. Electronic address:
Hyaluronic acid is a glycosaminoglycan present in uterine and oviductal fluids in female ruminants, which has been used as a sperm capacitation inducer prior to in vitro fertilization in several species. CD44 is a specific hyaluronic acid receptor, present in the sperm plasma membrane, but its signaling transduction system has not been elucidated yet. Our aim was to study protein kinase C and tyrosine kinase participation in intracellular signaling and oxidative metabolism in hyaluronic acid-induced capacitation of cryopreserved bull spermatozoa.
View Article and Find Full Text PDFAnim Reprod Sci
April 2017
Universidad de Buenos Aires, Facultad de Ciencias Veterinarias, Instituto de Investigación y Tecnología en Reproducción Animal (INITRA), Unidad Ejecutora de Investigaciones en Producción Animal UBA-CONICET (INPA), Cátedra de Química Biológica, Av. Chorroarín 280(1427), Ciudad Autónoma de Buenos Aires, Argentina. Electronic address:
Hyaluronic acid, as well as heparin, is a glycosaminoglycan present in the female genital tract of cattle. The aim of this study was to evaluate oxidative metabolism and intracellular signals mediated by a membrane-associated adenylate cyclase (mAC), in sperm capacitation with hyaluronic acid and heparin, in cryopreserved bull sperm. The mAC inhibitor, 2',5'-dideoxyadenosine, was used in the present study.
View Article and Find Full Text PDFAnim Reprod Sci
January 2016
Cátedra de Química Biológica, Instituto de Investigación y Tecnología en Reproducción Animal, Facultad de Ciencias Veterinarias, Universidad de Buenos Aires, Av. Chorroarín 280 1427 Ciudad Autónoma de Buenos Aires, Argentina. Electronic address:
Progesterone (P4) is capable of inducing acrosome reaction in many species. The objective of this study was to determine the activity of enzymes involved in metabolism that contribute to the redox state and supply energy for acrosome reaction in cryopreserved bull spermatozoa. To accomplish this aim, acrosome reaction was induced by P4 in capacitated and non-capacitated samples.
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