Platelet accumulation

During whipping these crystalline lipid platelets accumulate at the air-water interface of the air bubbles and also form bridges between them22,23. 

Oyekan AO, Botting JH (1986) A minimally invasive technique for the study of intravascular platelet aggregation in anesthetized rats. J Pharmacol Meth 15 271-277 Smith D, Sanjar S, Herd C, Morley J (1989) In vivo method for the assessment of platelet accumulation. J Pharmacol Meth 21 45-59... 

Moreover, Dionisotti and coworkers evaluated in vivo rabbit platelet accumulation in response to ADP, given either before or after drug infusion. NECA, and, to higher extent, HENECA clearly decreased platelet accumulation in the rabbit. This antiaggregatory activity is of short duration, and does not appear to be due to hemodynamic changes, but rather is a result of selective drug action on platelet adenosine receptors [25]. In the same experiment the selective Ai adenosine agonist CCPA resulted inactive. 

Our experimental model continuously evaluates net platelet accumulation, not necessarily thrombus growth and dissolution. These platelet kinetics are very unusual (see Figure 2) ... 

Figure 3. Platelet accumulation on the first 1 cm of fibrinogen-coated glass tubes versus time with and without thrombin prestimulation. (Reproduced with permission from Ref. 11. Copyright 1986 Pergamon Journals, Inc.)...

A capillary perfusion system has been developed for in vitro quantitation of protein adsorption and platelet accumulation on artificial surfaces under controlled... 

In platelet perfusion experiments, platelet accumulation on reactive adhesive surfaces such as collagen coated glass shows a steady decrease with distance from the capillary inlet, as previously observed in similar flow systems (20,21). This axial dependence does not, in our system, appear to follow a simple mathematical law as a function of distance from the capillary entrance (22). Platelet deposition is thus calculated as the mean deposition over the entire length ( < 10 cm) of a single capillary and in comparative studies capillaries cf equal length and internal diameter are considered. 

Table IV. Platelet Accumulation from Heparin Anticoagulated Whole Blood on Glass Capillary Surfaces Precoated v/ith Purified Human Albumin, Hnman Fibrinogen or Bovine Collagen. Quantitaticr of Platelet Deposition by Badioimmuroassay with Iodine Labeled Monoclonal Antibody 6C9 against Human Platelet Glycoprotein Complex Ilb-IIIa...

In summary, the capillary perfusion system represents a simple in vitrc technique for the quantitation of protein adsorption and platelet accumulation on artificial surfaces under well defined hydrodynamic conditions (0-4.,000 s ). Radioisotopic methods enable simultaneous study of platelet deposition and adsorption of one or more plasma proteins. Experiments may be performed using washed platelet suspensions or anticoagulated whole blood, platelet deposition being measured in the latter case by surface phase radioimmunoassay with a... 

Wilentz, J.R., Sanborn, T.A. Haudenschild, C.C., Valeri, R., Ryan, T.J. and Fanon, D.P. (1987). Platelet accumulation in experimental angioplasty time course and relation to vascular injury. Circulation, 75, 636-642... 

The sequence of events in homeostasis of larger vessels develops as follows platelets accumulate at the site of injury (forming a temporary clot), the vascular musculature (in arteries and large veins) constricts, and the platelet undergoes viscous metamorphosis. The mechanisms of aggregation and viscous metamorphosis of platelets will now be briefly reviewed. 

Randall, M. J., Wilding, R. I. R., 1983 Acute arterial thrombosis in rabbits reduced platelet accumulation after treatment with thromboxane synthetase inhibitor dizoxyben hydrochloride (UK-37,428-00). Br. J. Clin. Pharmacol. 15, 495-555. 

Bednar M, Smith B, Pinto A, MuUane KM (1985) Neutrophil depletion suppresses In-labeled platelet accumulation in infarcted myocardium. J Cardiovasc Pharmacol 7 906- 912... 

---