The significance of variations in immunoreactive and clottable fibrinogen in health and following thrombosis

Wolf, Peter; Farrell, Gillian; Walton, K. W.

doi:10.1136/jcp.25.1.36

Cited by 14 publications

(4 citation statements)

References 8 publications

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“…Transferrin was determined by the immunonephelometric assay (Buffone, Lewis, Losefsohn & Hicks, 1978). Fibrinogen was determined by the colourimetric method as described by Wolf, Farrell & Walton (1972). NPY was measured by radioimmunoassay (Brown, Allen & Fisher, 1989;Maisel et al, 1989).…”

Section: Assaysmentioning

confidence: 99%

Sympatho‐adrenal secretion in humans: factors governing catecholamine and storage vesicle peptide co‐release *

Takiyyuddin

Brown

Dinh

et al. 1994

Journal of Autonomic Pharmacology

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1. In postganglionic sympathetic neurones and adrenal chromaffin cells, catecholamines are co-stored in vesicles with soluble peptides, including chromogranin A (CgA) and neuropeptide Y (NPY), which are subject to exocytotic co-release with catecholamines. 2. Plasma catecholamine, CgA and NPY responses to stimulators and inhibitors of sympatho-adrenal catecholamine storage and release were measured in humans. Short-term, high-intensity dynamic exercise, prolonged low-intensity dynamic exercise, and assumption of the upright posture, in decreasing order of potency, predominantly stimulated noradrenaline (NA) release from sympathetic nerve endings. Only high-intensity exercise elevated CgA and NPY, which did not peak until 2 min after exercise cessation. Stimulated NA correlated with plasma CgA 2 min after exercise, and with NPY 5 min after exercise. 3. Insulin-evoked hypoglycaemia and caffeine ingestion, in decreasing order of potency, predominantly stimulated adrenaline (AD) release from the adrenal medulla. During insulin hypoglycaemia AD and CgA rose, but NPY was unchanged. Neither NPY nor CgA were altered by caffeine. The rise in CgA after intense adrenal medullary stimulation was greater than its rise after intense sympathetic neuronal stimulation (1.4-versus 1.2-fold, respectively). 4. Infusion of tyramine, which disrupts sympathetic neuronal vesicular NA storage, elevated systolic blood pressure and NA, while NPY and CgA were unchanged. After reserpine, another disruptor of neuronal NA storage, NA transiently rose and then fell; NPY and CgA were unaltered. After the non-exocytotic adrenal medullary secretory stimulus glucagon. AD rose while NA, CgA and NPY did not change. After amantadine, an inhibitor of protein endocytosis, both CgA and fibrinogen rose, while NA and NPY remained unaltered. Neither CgA, NPY, nor catecholamines were altered by the catecholamine uptake and catabolism inhibitors desipramine, cortisol, and pargyline. 5. Human sympathetic nerve contained a far higher ratio of NPY to catecholamines than human adrenal medulla, while adrenal medulla contained far more CgA than sympathetic nerve. 6. It is concluded that peptides are differentially co-stored with catecholamines, with greater abundance of CgA in the adrenal medulla and NPY in sympathetic nerve. Activation of catecholamine release from either the adrenal medulla or sympathetic nerves, therefore, results in quite different changes in plasma concentrations of the catecholamine storage vesicle peptides CgA and NPY. Only profound, intense stimulation of chromaffin cells or sympathetic axons measurably perturbs plasma CgA or NPY concentration; lesser degrees of stimulation perturb plasma catecholamines only. Neither CgA nor NPY are released during non-exocytotic catecholamine secretion.

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Section: Assaysmentioning

confidence: 99%

Sympatho‐adrenal secretion in humans: factors governing catecholamine and storage vesicle peptide co‐release *

Takiyyuddin

Brown

Dinh

et al. 1994

Journal of Autonomic Pharmacology

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“…During the menstrual phase, immunoreactive fibrinogen is higher than fibrinogen assayed by the thrombin clotting technique because of the increased concentration of circulating fibrinogen fragments generated by the breakdown of the endometrium. 22 In our study concentrations of immunoreactive fibrinogen were actually lower than thrombin clottable fibrinogen in both the patient and control groups which makes it unlikely that there were increased amounts of circulating fibrin fragments in our group of patients or controls.…”

Section: Discussionmentioning

confidence: 47%

Comparison of an immunochemical assay for plasma fibrinogen and a turbidimetric thrombin clotting technique to discriminate hyperlipidaemic patients from healthy controls.

et al. 1990

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Plasma samples from patients attending a lipid clinic (n = 14) and healthy control subjects (n = 21) were assayed for fibrinogen using an immunochemical method (radial immunodiffusion) and a turbidimetric assay based on the thrombin clotting technique. The patients had significantly higher plasma fibrinogen concentrations than controls by both methods, but there was significant overlap between the two groups when fibrinogen was assayed by the thrombin clotting technique; there was almost complete separation of the two groups using the immunochemical assay. This difference in overlap could not be attributed to the presence or absence of fibrinogen degradation products. These findings may have important implications for the choice of method for determining plasma fibrinogen when assays are used for the assessment of cardiovascular risk. It is recommended that plasma fibrinogen should be assayed by both an immunochemical and a thrombin clotting method.

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“…This suggests that in these conditions an increased production of fibrinogen, which is normally functional, oc curs. 260 Prisco et al Discrepancies between results obtained by radial immunodiffusion and the thrombin clotting technique have been reported follow ing surgery or extensive intravascular throm bosis [10] and in patients treated with strepto kinase [11] possibly due to the interference of fibrinogen degradation products. In the present study, fibrin degradation products were measured as D-dimer in pregnant wom en and were found mildly higher than normal range values of our laboratory, as similarly observed by Nolan et al [12].…”

Section: Discussionmentioning

confidence: 99%

Clottable to Immunological Fibrinogen Ratio in Plasma from Control Subjects and Hyperfibrinogenemic Patients

Prisco

Zarone²,

Liotta³

et al. 1995

Pathophysiol Haemos Thromb

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The measurement of fibrinogen (Fg) plasma levels is one of the more frequently performed tests in clinical practice, usually by clotting assay. However, for the diagnosis of dysfibrinogenemia the use of an immunological assay is necessary to compare total and clottable protein. Little information is available on the range of the ratio clottable (C) Fg/immunological (I) Fg levels in normal population. This study aimed at evaluating the CFg/IFg ratio in 70 control subjects (age range 17-74 years – group A), in 57 acute patients (age range 17-79 years – group B) and in 14 pregnant women (age range 27-41 years, pregnancy weeks 30-40 – group C), as a physiologic model of hyperfibrinogenemia. CFg was assayed on citrated plasma by the Clauss clotting method and IFg was assayed by radial immunodiffusion technique. In the three groups, CFg/IFg ratios were not significantly different (respectively group A 0.98 ± 0.17, group B 1.02 ± 0.18 and group C 1.01 ± 0.11), whereas both CFg (310 ± 45 mg/dl) and IFg (326 ± 70mg/dl) levels were lower (p < 0.001) in control subjects than in patients (CFg 556 ± 92 mg/dl; IFg 561 ± 121 mg/dl) and in pregnant women (CFg 530 ± 65 mg/dl; IFg 530 ± 77 mg/dl). The analysis of the relationship between CFg and IFg in the three groups (group A: y = 11.53 + 1.01x, r = 0.64, p < 0.001; group B: y = 68.72 + 0.88x, r = 0.67, p < 0.001; group C: y = 71.59 + 0.87x, r = 0.73, p < 0.01) indicates that a good correlation exists (p < 0.001) for values of fibrinogenemia ranging from 180 to over 700 mg/dl. A reference range of CFg/IFg (mean ± 2 SD in group A) was 0.64-1.32. These data could be of practical importance for a rapid screening of dysfibrinogenemias.

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The significance of variations in immunoreactive and clottable fibrinogen in health and following thrombosis

Cited by 14 publications

References 8 publications

Sympatho‐adrenal secretion in humans: factors governing catecholamine and storage vesicle peptide co‐release *

Sympatho‐adrenal secretion in humans: factors governing catecholamine and storage vesicle peptide co‐release *

Comparison of an immunochemical assay for plasma fibrinogen and a turbidimetric thrombin clotting technique to discriminate hyperlipidaemic patients from healthy controls.

Clottable to Immunological Fibrinogen Ratio in Plasma from Control Subjects and Hyperfibrinogenemic Patients

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