The intracellular pH of the human platelet.

Zieve, Philip D.; Solomon, Harvey M.

doi:10.1172/jci105431

Cited by 33 publications

(12 citation statements)

References 9 publications

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“…The highest concentration ratio for the distribution of intact adrenaline between platelets and the plasma in which they were suspended was about 12. When the pH of the medium is 7-4, the intracellular oH of human platelets is about 7 1 (Zieve & Solomon, 1966); therefore, the concentration ratio for adrenaline is higher than can be accounted for by a Donnan distribution. On the other hand, the ratio is much lower than the very high ratios for 5-hydroxytryptamine which are due to its accumulation in the organelles.…”

Section: Discussionmentioning

confidence: 96%

Uptake, metabolism and release of [³H]‐adrenaline by human platelets

Born

Smith

1970

British J Pharmacology

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Summary1. Measurements were made of the uptake, metabolism and release of [3H]-adrenaline by human platelets in citrated plasma or in an artificial medium. 2. Radioactive adrenaline was not taken up at 0-2°C. At 370 C there was a slow uptake which continued for at least 5 hours.3. About half of the radioactivity in the platelets was intact adrenaline. The other half was an acidic metabolite from which adrenaline was released by acid hydrolysis. 4. The immediate uptake of adrenaline was proportional to its concentration in the plasma up to at least 1 x 1O-5M. Uptake measured after 1 h also increased linearly with concentration up to about 1 x 10-4M but less with higher concentrations. The highest concentration ratio was about 12. 5. The concentration of metabolite in the platelets increased with the concentration of added adrenaline only up to about 2 x 10-m. 6. The immediate uptake of adrenaline was partially inhibited by phentolamine and dihydroergotamine. Measurement of uptake both immediately and after 1 h showed that the inhibition produced was not increased beyond about 50% by these drugs or by (±)-propranolol, chlorpromazine or amitriptyline up to 1 x 10 'M. 7. Formation of the metabolite was inhibited by pyrogallol, 8-hydroxyquinoline, or tropolone. This inhibition was associated with a corresponding increase in the adrenaline accumulated intact. Formation of the metabolite was not inhibited by monoamine oxidase inhibitors. 8. Reserpine caused a small decrease in the uptake of adrenaline radioactivity in 1 h and a great increase in the proportion recovered as metabolite. 9. Thrombin caused the release from platelets of intact adrenaline but not of the metabolite. 10. Platelets of albino patients with spontaneous haemorrhages accumulated adrenaline radioactivity at the normal rate but this radioactivity was wholly accounted for by metabolite and not released by thrombin. 11. After taking up adrenaline, platelets resuspended in artificial medium at 370 C slowly released both adrenaline and its metabolite. At the same time, the intracellular adrenaline was slowly metabolized.

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Section: Discussionmentioning

confidence: 96%

Uptake, metabolism and release of [³H]‐adrenaline by human platelets

Born

Smith

1970

British J Pharmacology

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“…1 and 2). Work in vitro with Ehrlich ascites cells (Poole et al, 1964) and human platelets (Zieve and Solomon, 1966) has shown that the relationship between pHi and pHe may not remain constant over the range pH 6-0-8-0. Indeed, with glycolysing Ehrlich ascites cells in bicarbonate buffer, the pHi may be rising at a time when the pHe is falling (Poole et al, 1964).…”

Section: Discussionmentioning

confidence: 99%

The sensitivity of a malignant cell line to hyperthermia (42°C) at low intracellular pH

Dickson¹,

Oswald²

1976

Br J Cancer

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Summary.-The postulate that low intracellular pH acts as a preconditioner for the destructive effects of hyperthermia (42°C) was examined, using a heat-sensitive line of malignant cells derived from rat mammary gland (SDB). Intracellular pH (pHi) was measured indirectly, from the distribution of the weak, non-metabolizable organic acid 5,5-dimethyl-2,4-oxazolidinedione (DMO) between intra-and extracellular water. Respiration, aerobic and anaerobic glycolysis of the cells were studied at normal pHi (pH 7.0-7.4) or at low pHi (pH 6.2-6.6) and at 38°C or 42°C over 6 h in Warburg manometers; the ability of the cells to replicate in culture was examined after 3 h or 6 h incubation in the flasks.The relationship between pHi and extracellular pH (pHe) depended upon the buffer system used and the exact pH in question; no assumption regarding pHi based only on pHe measurement could be made. At 38°C and low pHi, the Pasteur effect became negative due to a relatively greater inhibition of anaerobic than aerobic glycolysis. Respiration was unaffected and cell replicative ability unimpaired. At 42°C and normal pHi, respiration was totally inhibited after 4 h and the Pasteur effect was decreased, in this case due to a compensatory increase in aerobic glycolysis without alteration in anaerobic CO2 production. Low pHi in the presence of hyperthermia enabled cell respiration to continue at a reduced level with no further change in glycolysis. There was delayed cell replication after 3 h at 42°C and inability to multiply following 6 h hyperthermia: low pHi did not influence these results.It is concluded that with these cancer cells, pHi values maintained in the region of 1.0 pH unit below normal for 6 h had no deleterious effect on the cells. No sensitizing effect of the low pHi for the destructive effect of hyperthermia on the cells was observed.

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“…The chloride equilibrium potential is not well-known. Determinations using 36C1 and coulometry vary from ~ 80 to 30 mM [Zieve et al, 1967;Grinstein et al, 1982b;Felber and Brand, 1982;Negendank, 1984]. Thus Eq could be as positive as -10 mV or as negative as -37 mV in the isotonically bathed, quiescent lymphocyte.…”

Section: Dynamic Forces Governing Rv Dmentioning

confidence: 99%

Cell Volume Regulation in Lymphocytes

Deutsch¹,

Lee²

1988

Kidney Blood Press Res

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This article reviews what is known about the volume regulatory responses of lymphocytes. We present a discussion of recent data and hypotheses pertaining to the underlying mechanisms in regulatory volume increase (RVI) and regulatory volume decrease (RVD). New results from our laboratory are included to demonstrate that RVD is modulated by both temperature and pH, and that RVD occurs in proliferating as well as quiescent lymphocytes. This information is considered in the context of a model that includes the dynamics of membrane potential, K⁺ conductance, Cl^- conductance, a proposed stretch-activated conductance, gating mechanisms, and equilibrium potentials, as RVD progresses. The physiological relevance of volume homeostasis in lymphocyte function, in particular, and in cell growth and proliferation, in general, is discussed.

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The intracellular pH of the human platelet.

Cited by 33 publications

References 9 publications

Uptake, metabolism and release of [³H]‐adrenaline by human platelets

Uptake, metabolism and release of [³H]‐adrenaline by human platelets

The sensitivity of a malignant cell line to hyperthermia (42°C) at low intracellular pH

Cell Volume Regulation in Lymphocytes

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The intracellular pH of the human platelet.

Cited by 33 publications

References 9 publications

Uptake, metabolism and release of [3H]‐adrenaline by human platelets

Uptake, metabolism and release of [3H]‐adrenaline by human platelets

The sensitivity of a malignant cell line to hyperthermia (42°C) at low intracellular pH

Cell Volume Regulation in Lymphocytes

Contact Info

Product

Resources

About

Uptake, metabolism and release of [³H]‐adrenaline by human platelets

Uptake, metabolism and release of [³H]‐adrenaline by human platelets