Incorporation of A23187 ionophore into the human-hamster fertilization system clearly improves the ability of human spermatozoa to penetrate zona-free hamster oocytes. Thus, an increasing number of laboratories working in human sperm cytogenetics have substituted classical incubation with Biggers-Whitten-Whittingham (BWW) medium plus human serum albumin (HSA) by pretreatment of spermatozoa with...

Bovine epididymal spermatozoa incubated aerobically in vitro in the presence of 0.1 to 0.2 mM CaCl2 accumulate 25 to 50 nmol of calcium/10(8) cells. The addition of low concentrations of the ionophore A23187 (0.01 to 0.5 nmol/mg of sperm protein) induces efflux of this accumulated calcium. At high ionophore concentrations (0.5 to 5.0 nmol/mg of sperm protein), calcium release is followed by an ...

The effect of the calcium ionophore A23187 on the release and metabolism of [3H]arachidonic acid was examined in normal polymorphonuclear leukocytes and those obtained from patients with chronic granulomatous disease. The ionophore A23187 which stimulates oxidative metabolism in normal polymorphonuclear leukocytes was ineffective in increasing oxidative metabolism (chemiluminescence) in polymor...

Experiments were conducted to examine the in vitro effects of a phorbol ester and a calcium ionophore on bovine luteal oxytocin (OT) secretion and synthesis and progesterone secretion. Corpora lutea removed from beef heifers on d 8 of an estrous cycle were sliced and incubated for 2 h with .81 nM 12-O-tetradecanoylphorbol-13-acetate (TPA), 1.62 nM TPA or .3 microM calcium ionophore A23187. Both...

Toxoplasma gondii tachyzoites markedly alter the profile of eicosanoids released by human mononuclear phagocytes. Freshly isolated, 2-h adherent human monocytes release both cyclooxygenase (e.g., thromboxane [TX] B2, prostaglandin [PG] E2) and 5-lipoxygenase (e.g., leukotriene [LT] B4, LTC4) products of arachidonic acid metabolism after stimulation by the calcium ionophore A23187 or ingestion o...

The coagulant activity of tissue factor (TF) in the membranes of cultured cells is increased after physical disruption f the cells, and a similar increase can be elicited by treatment of cell cultures with calcium ionophore and calcium. We observed that the supernatants of cultures treated with calcium and ionophore CBI-A23187 contained more TF activity than those of control cultures. Phase con...

The coagulant activity of tissue factor (TF) in the membranes of cultured cells is increased after physical disruption f the cells, and a similar increase can be elicited by treatment of cell cultures with calcium ionophore and calcium. We observed that the supernatants of cultures treated with calcium and ionophore CBI-A23187 contained more TF activity than those of control cultures. Phase con...

The coagulant activity of tissue factor (TF) in the membranes of cultured cells is increased after physical disruption of the cells, and a similar increase can be elicited by treatment of cell cultures with calcium ionophore and calcium. We observed that the supernatants of cultures treated with calcium and ionophore 4-Br-A23187 contained more TF activity than those of control cultures. Phase c...

The effects of vasopressin, angiotensin II, and calcium ionophore A23187 were examined and compared on endogenous prostaglandin E2 (PGE2) production, in the absence of exogenous arachidonate, by glomeruli and cortical and medullary collecting tubules freshly prepared from rat kidney. Angiotensin II stimulated PGE2 production in the glomeruli but not in the collecting tubules. Vasopressin at con...