Precise regulation of neurotransmitter release is essential for the normal function of neural networks, but the mechanisms involved are largely unclear. Using superfused synaptosomes, we have studied the readily releasable pool of synaptic vesicles, measured as the amount of release triggered by hypertonic sucrose. We show that activation of presynaptic metabotropic glutamate receptors by dihyd...

The heparin-releasable proteins are a group of proteins that are targeted to the endothelial surface by attachment to glycosaminoglycans and may have functions specific to the endothelium-blood interface. In this study, heparin-affinity chromatography of human postheparin plasma was used as a method to identify and study novel heparin-releasable proteins. Six proteins seen on sodium dodecyl sul...

abstract background: the cosmetic result of the surgical scar has long been considered by surgeons as an important factor for patient satisfaction. on the other hand, there has been an old teaching that perfect closure of contaminated wounds increases the rate of infection. we decided to look into this matter and see if this is a fact or a myth. methods: in this prospective randomized study con...

Treatment of isolated myofibrils with an ATP-containing relaxing solution results in the dissociation of a preformed quantity of myofilaments called 'easily releasable myofilaments'. Van der Westhuyzen, Matsumoto & Etlinger [(1981) J. Biol. Chem. 256, 11791-11797] presented experimental evidence that these myofilaments represent intermediate products in the turnover of myofibrillar proteins. To...

Vascular endothelial-bound lipoprotein lipase (LPL), also known as heparin-releasable LPL, catalyzes the breakdown of the triglyceride component of lipoproteins and is rate-limiting for free fatty acid transport to tissues. We previously demonstrated that heparin-releasable LPL activity increases in diabetic Wistar rat hearts, whereas with the development of hypertension in spontaneously hypert...

Recovery from synaptic depression is believed to depend mainly on replenishment of the releasable pool of vesicles. We observed that during recovery from depression in a calyx-type synapse, part of the releasable pool was replenished rapidly. Half recovery occurred within 1 s, even in the absence of residual calcium. Vesicles that had recently entered the releasable pool had a 7- to 8-fold lowe...

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Vesicular catecholamine release has been measured amperometrically from undifferentiated rat PC12 cells using carbon fiber microelectrodes. During superfusion with high K(+) saline, vesicular release was detected from approximately 50% of 200 cells investigated. On repeated stimulation the releasable pool of vesicles is rapidly depleted, while vesicle contents remains constant. Vesicular catech...

Modulation of the size of the readily releasable vesicle pool has recently come under scrutiny as a candidate for the regulation of synaptic strength. Using electrophysiological and optical measurement techniques, we show that phorbol esters increase the size of the readily releasable pool at glutamatergic hippocampal synapses in culture through a protein kinase C (PKC)-dependent mechanism. Pho...

OBJECTIVE Tissue factor pathway inhibitor (TFPI) is an endothelial-associated inhibitor of blood coagulation. Because the mechanism for attachment of TFPI to endothelium is not clear, we investigated its association with human placenta. METHODS AND RESULTS Western blots demonstrate that treatment with phosphatidylinositol-specific phospholipase C (PIPLC) removes more placental TFPI than eithe...