+ Site Statistics
+ Search Articles
+ Subscribe to Site Feeds
EurekaMag Most Shared ContentMost Shared
EurekaMag PDF Full Text ContentPDF Full Text
+ PDF Full Text
Request PDF Full TextRequest PDF Full Text
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter
Follow on LinkedInFollow on LinkedIn

+ Translate

Platelet uptake of octopamine and norepinephrine in hepatic encephalopathy

Platelet uptake of octopamine and norepinephrine in hepatic encephalopathy

Gastroenterology 73(3): 560-564

To explore platelets as a model of intracellular [neuronal] amine metabolism in liver disease, platelet uptake of octopamine (OA) was studied in controls and patients with hepatic encephalopathy (HE), and the influence of OA and plasma from patients with HE on platelet norepinephrine uptake was investigated. Normal platelets incubated at C actively accumulated OA. A high ratio of platelet OA concentration to plasma concentration (30:1) and inhibition of platelet OA uptake at reduced temperature suggested uptake by an active process. More than 90% of AO accumulated by platelets was recovered intact after 1 h. Thrombin released 40% of platelet OA, suggesting sequestration within amine storage granules. OA inhibited the uptake of [3H] norepinephrine (NE) by platelets, suggesting that these substances share the same transfer system. Platelets of patients with HE demonstrated decreased uptake of OA and NE. Inhibition of platelet OA uptake was proportional to the clinical stage of HE. Plasma from patients with HE inhibited NE uptake by normal platelets. Plasma OA and/or other amines are apparently taken up by platelets where they are protected from degradation. The reduced uptake of OA and NE by platelets from patients with HE could result from uptake blockade by intraplatelet amines and/or inhibition of platelet amine uptake by plasma amines. The demonstration of altered platelet OA and NE metabolism in patients with encephalopathy suggested that this model may be useful for the study of intracellular amines in liver disease.

(PDF emailed within 1 workday: $29.90)

Accession: 006135217

Download citation: RISBibTeXText

PMID: 330303

Related references

Hepatic encephalopathy EEG and octopamine. Journal of Clinical Psychiatry 41(5): 175-177, 1980

Hepatic encephalopathy electro encephalogram and octopamine. Journal of Clinical Psychiatry 41(5): 175-177, 1980

Phenyl ethanolamine and octopamine in hepatic encephalopathy. Mosnaim, A D And M E Wolf (Ed ) Modern Pharmacology-Toxicology, Vol 12 Noncatecholic Phenylethylamines, Part 2 Phenylethanolamine, Tyramines, And Octopamine Xv+365p Marcel Dekker, Inc : New York, N Y , Usa: Basel, Switzerland Illus P231-244, 1980

Octopamine and ammonia plasma levels in hepatic encephalopathy. Clinica Chimica Acta 75(1): 99-106, 1977

Octopamine plasma levels and hepatic encephalopathy: a re-appraisal of the problem. Clinica Chimica Acta; International Journal of Clinical Chemistry 67(3): 255-261, 1976

Influence of phenylethanolamine on octopamine plasma determination in hepatic encephalopathy. Clinica Chimica Acta 93(3): 371-376, 1979

Role of a false neurotransmitter, octopamine, in the pathogenesis of hepatic and renal encephalopathy. Scandinavian Journal of Gastroenterology 8(6): 465-472, 1973

The role of the false neuro transmitter octopamine in the pathogenesis of hepatic encephalopathy. Australian & New Zealand Journal of Medicine 3(1): 102-103, 1973

Octopamine and phenyl ethanolamine cerebral arterio venous difference in hepatic encephalopathy. Clinical Research 27(4): 662A, 1979

Simultaneous analysis of plasma phenethylamine, phenylethanolamine, tyramine and octopamine in patients with hepatic encephalopathy. Clinica Chimica Acta; International Journal of Clinical Chemistry 199(1): 91-97, 1991

Determinants of platelet norepinephrine content uptake and retention of norepinephrine in vitro. Clinical Research 32(4): 791A, 1984

Simultaneous radio enzymatic determination of phenethylamine phenyl ethanolamine tyramine and octopamine in plasma of patients with hepatic encephalopathy. Clinical Biochemistry 14(4): 187-190, 1981

A selective radioenzymatic assay for the determination of octopamine and phenylethanolamine in plasma and cerebrospinal fluid. Preliminary results in human and experimental hepatic encephalopathy. Italian Journal of Biochemistry 27(6): 450-465, 1978

Platelet uptake of noradrenaline norepinephrine in relation to amine induced platelet aggregation abstract. Proc Int Union Physiol Sci 7(24): 69, 1968