Demonstration and evaluation of apparent cytoplasmic and vesicular serotonin compartments in human platelets

Costa, Jonathan L.; Murphy, Dennis L.; Kafka, Marian S.

doi:10.1016/0006-2952(77)90327-6

Cited by 50 publications

(31 citation statements)

References 13 publications

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“…Human platelets from normal volunteers were collected in citrate/disodium edetate (EDTA), and platelet-rich-plasma (PRP) was prepared by differential centrifugation at 4°C as described previously (Costa et al, 1977a). All platelet counts were performed with an Electrozone Celloscope (Particle Data, Inc., Elmhurst, Ill.).…”

Section: Methodsmentioning

confidence: 99%

“…Calculation of the amounts of radioactively-labelled material in the vesicular compartment was made as described previously, using formaldehyde fixation and thrombin (Costa et al, 1977a). Briefly, PRP was incubated with 2 x 10-7 M ['4C]-5-HT for 30 min at 37°C.…”

Section: Methodsmentioning

confidence: 99%

“…Recently-developed techniques, using formaldehyde fixation (Costa & Murphy, 1975) in conjunction with thrombin (Costa, Murphy & Kafka, 1977a), permit evaluation of the accumulation of radioactively-labelled substances into a platelet thrombinreleasable compartment, believed to represent the vesicular storage site. Using these methods, we have compared the distribution in intact platelets of 5-HT and other amines of biological interest in platelet cytoplasm and storage vesicles.…”

Section: Introductionmentioning

confidence: 99%

“…Briefly, PRP was incubated with 2 x 10-7 M ['4C]-5-HT for 30 min at 37°C. Platelets were cooled to 0°C, spun into a pellet, and resuspended to a final concentration of 1-2 x 108/ml in a Tris-citrate buffer (Costa et al, 1977a). Under these conditions, the [14C]-5-HT can be used to follow the behaviour of the endogenous 5-HT…”

mentioning

confidence: 99%

“…tyramine on the movement of new 5-HT into vesicles. However, we could not employ the same protocol as used above, since relatively large pools of cytoplasmic 5-HT will migrate completely into vesicles following resuspension in an amine-free medium (Costa et al, 1977a;Costa, Silber & Murphy, 1977b …”

mentioning

confidence: 99%

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Evaluation of the Uptake of Various Amines Into Storage Vesicles of Intact Human Platelets

Costa

Murphy

Reveille³

1977

British J Pharmacology

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The uptake of various 3H‐labelled amines into a thrombin‐releasable compartment of human platelets, thought to represent the platelet vesicular storage pool, has been evaluated. Measurable amounts of 5‐hydroxytryptamine (5‐HT), dopamine, tyramine, octopamine, and tryptamine accumulate in this pool, and also in a non‐thrombin‐releasable (cytoplasmic) pool during a 30 min incubation period with 10−5 M extracellular amine concentrations. No differences in the accumulation of vesicular or cytoplasmic 5‐HT, dopamine, and tyramine are found in platelets treated with deprenyl to inhibit platelet monoamine oxidase as compared to controls. Extracellular tyramine or dopamine in concentrations as high as 10−5 M does not alter the initial rate of 5‐HT uptake across the platelet plasma membrane. Similarly, sizable cytoplasmic pools of either amine do not alter the initial rate at which small amounts of 5‐HT enter platelet cytoplasm or storage vesicles. 5‐HT thus appears to be the preferred substrate for uptake into platelets and for movement from cytoplasm to vesicles.

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Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

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Evaluation of the Uptake of Various Amines Into Storage Vesicles of Intact Human Platelets

Costa

Murphy

Reveille³

1977

British J Pharmacology

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A role for anion transport in the regulation of release from chromaffin granules and exocytosis from cells

et al. 1977

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Release of epinephrine from isolated adrenergic secretory veiscles from the adrenal medulla (chromaffin granules) was found t o be inhibited by a number of anion transport blocking agents, including SITS, probenecid, pyridoxal phosphate, and Na-isethionate. High concentrations of permeant anion, such as chloride, are required for granule release and the drugs were found t o be competitive inhibitors with respect to chloride. The anion transport blockers were also found t o suppress exocytosis of serotonin from human platelets and parathyroid hormone from dissociated bovine parathyroid cells. By contrast, they had no effect o n ACTH-activated corticosterone secretion from dissociated rat adrenocortical cells, a process which occurs by diffusion rather than exocytosis. The important anion in the medium for human platelets was hydroxyl ion, rather than chloride, and the most effective drug on platelets was suramin. Isethionate was inactive. In the case of PTH secretion, both chloride and hydroxyl ions were important anions and were both competitively inhibited by anion blocking drugs including Na-isethionate. We conclude from these studies that the chemistry of exocytosis appears t o be quite similar t o the chemistry of release from isolated secretory vesicles. We suggest that when vesicles are fused t o plasma membranes prior t o exocytosis they are exposed t o higher chloride and hydroxyl ion concentrations of the medium, and that inward anion flux into the vesicle promotes release, possibly by local osmotic lysis. Blockade of exocytosis by anion transport blocking drugs would occur by inhibition of inward anion flux into the fused vesicle, by analogy with previous results from studies on isolated chromaffin granules.Key words: anion transport, chromaffin granules, exocytosis, platelets, parathyroid hormone Many neurotransmitters, hormones, and enzymes are stored in intracellular secretory vesicles and, in response t o appropriate stimuli, are released into the extracellular compartment by exocytosis (1). The process seems well defined ultrastructurally but the chemical and energetic basis for exocytosis remains obscure.

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Biochemical Studies on Autism

Yuwiler

Geller

Ritvo

1985

Pathological Neurochemistry

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Demonstration and evaluation of apparent cytoplasmic and vesicular serotonin compartments in human platelets

Cited by 50 publications

References 13 publications

Evaluation of the Uptake of Various Amines Into Storage Vesicles of Intact Human Platelets

Evaluation of the Uptake of Various Amines Into Storage Vesicles of Intact Human Platelets

A role for anion transport in the regulation of release from chromaffin granules and exocytosis from cells

Biochemical Studies on Autism

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