The aim of this study was to improve in vitro embryo development of prepubertal goat oocytes by studying the effect of adding cysteamine to in vitro maturation medium, glutathione (GSH) to in vitro fertilization medium and ionomycin to the sperm capacitation medium. In experiment 1, we analysed the effect of 1 mM GSH added to fertilization medium of oocytes matured with 400 microM cysteamine. T...

To study the mechanism of vasodilation induced by 6-(3-dimethylaminopropionyl) forskolin (NKH477), a water-soluble forskolin derivative, its effects on the acetylcholine (ACh)-induced contraction of muscle strips of porcine coronary artery were examined. [Ca2"]1, isometric force, and cellular concentrations of cAMP and inositol 1,4,5-trisphosphate were measured. NKH477 (0.1-1.0 ,uM), isoprotere...

BACKGROUND In some couples, not all retrieved oocytes mature, even after prolonged in vitro culture. The underlying mechanisms are not known, although ionophore treatment may alleviate metaphase I (MI) arrest in some mouse strains. We attempted to induce first polar body (PB) extrusion and fertilization using assisted oocyte activation (AOA) after ICSI in maturation-resistant human MI oocytes. ...

Lactating mammary epithelial cells secrete high levels of caseins and other milk proteins. The extent to which protein secretion from these cells occurs in a regulated fashion was examined in experiments on secretory acini isolated from the mammary glands of lactating mice at 10 d postpartum. Protein synthesis and secretion were assayed by following the incorporation or release, respectively, o...

The CTLA-4 (CD152) molecule is up-regulated upon T cell activation and proliferation, and plays a critical role in the inhibition of immune responses. We show in this study that cAMP induces up-regulation of CD152 in human CD4(+) T lymphocytes. This effect occurs in the absence of the up-regulation of CD69 and CD25 activation markers and T cell proliferation. In addition, we found that the Ca(2...

Xiao, Weiqun, Ying Liu, and Douglas M. Templeton. Ca / calmodulin-dependent protein kinase II inhibition by heparin in mesangial cells. Am J Physiol Renal Physiol 288: F142–F149, 2005. First published September 21, 2004; doi:10.1152/ajprenal.00145.2004.— Heparin exerts an antiproliferative effect in smooth muscle cells, and the Ca /calmodulin-dependent protein kinase (CaMK) signaling pathway is...

Heparin exerts an antiproliferative effect in smooth muscle cells, and the Ca(2+)/calmodulin-dependent protein kinase (CaMK) signaling pathway is heparin sensitive. Here, we report that transfection with a truncated 326-amino acid fragment of CaMK-IIalpha increases basal activity of CaMK-II in mesangial cells. Ionomycin increased CaMK-II activity in both transfected and untransfected cells, wit...

An increase in intracellular Ca2+ is one of the initiating events in T-cell activation. A calcium-mediated signalling cascade in T-cells involves activation of calcineurin and the dephosphorylation and translocation of NFAT (nuclear factor of activated T-cells), resulting in the transcriptional activation of target genes such as IL-2 (interleukin-2). In the present study, we found that increase...