The objective of this study was to compare the effectiveness of various combination activators of bovine oocyte following intracytoplasmic sperm injection (ICSI) in terms of cleavage and embryo development. Bovine ICSI oocytes were treated with a variation of treatments of combined or single activators as follows; 30 V for 15 x 2 μsec of electrical pulse +10 μg/mL cycloheximide (CHX),7% ethanol...

The contractile and biochemical effects of the divalent cation ionophore A23187 were studied in isolated perfused guinea pig and rat ventricles. A23187 increased both cyclic adenosine 3':5'monophosphate (cyclic AMP) and cyclic guanosine 3':5'-monophosphate (cyclic GMP) concentrations in guinea pig ventricles. Associated with these changes in nucleotide content were positive inotropic effects an...

Methods. Soluble and insoluble lens proteins from 4-day-old to 4-month-old rat lens cortexes and nuclei were separated by two-dimensional electrophoresis. The insoluble proteins from 4-month-old nuclei were electroblotted and the NH2 termini of proteins sequenced. Cleavage sites appearing at 4 months of age were compared to cleavage sites produced by purified calpain II and to cleavage sites ap...

BACKGROUND Translocation of phosphatidylserine (PS) from the inner to the outer leaflet of the plasma membrane is a modification of the lipid architecture occurring in sperm. This is one of the earliest signs of apoptosis that can be monitored by the calcium-dependent binding of annexin V. METHODS AND RESULTS Flow cytometric analysis of annexin V binding was performed. Calcium ionophore A2318...

PURPOSE To determine if the susceptibility of rat lenses to cataract formation in culture changes with increasing age and to investigate the regional differences in crystallin degradation and insolubilization during the formation of cataracts in cultured lenses. METHODS Lenses from 4-week-old (young group) and 12-week-old (adult group) rats were divided into four subgroups: noncultured contro...

We designed experiments to characterize the role of superoxide anions in the mediation of endothelium-dependent contractions in isolated canine basilar arteries. Rings with and without endothelium were suspended for isometric tension recording in Krebs-Ringer bicarbonate solution bubbled with 94% O2-6% CO2 (37 degrees C, pH 7.4). Radioimmunoassay was used to determine the levels of cyclic GMP a...

The role of calcium in the relaxations evoked by methacholine and A23187 in intact rabbit aortic rings was investigated. Methacholine (10(-8) to 10(-6) M) and the calcium ionophore A23187 (10(-8) to 10(-6) M) produced dose-dependent relaxations of rings which had been contracted with the alpha-adrenergic agonist phenylephrine. The ability of a ring to relax in this manner was correlated with th...

Thimet oligopeptidase (EC 3.4.24.15; EP24.15) was originally described as a neuropeptide-metabolizing enzyme, highly expressed in the brain, kidneys and neuroendocrine tissue. EP24.15 lacks a typical signal peptide sequence for entry into the secretory pathway and is secreted by cells via an unconventional and unknown mechanism. In this study, we identified a novel calcium-dependent interaction...

Haploinsufficiency of elastin leads, in more than half of patients with Williams-Beuren syndrome, to development of supravalvular aortic stenosis and hypertension. Determining mechanisms implicated in elastin synthesis would be of interest to find new elastogenic molecules to treat such a pathology. Here, we analyzed the signaling pathway linking intracellular calcium concentration to elastin r...

Calcium antagonists inhibit platelet aggregation, but whether this action is due to inhibition of the effect of agonists on cytoplasmic ionized calcium concentration is unknown. We studied this problem by loading gel-filtered platelets with either quin2 or aequorin and stimulating them with epinephrine, arachidonate, thrombin, the calcium ionophore A23187, 1-oleoyl-2-acetyl glycerol, or adenosi...