Quantitation by radioimmunoassay of PAF in human saliva

Abstract

Approximately 75% of the PAF present in saliva is recovered on extraction of whole saliva (0.8 vol) with chloroform/methanol/water (2:2:1, v/v/v). PAF levels, determined by our recently developed radioimmunoassay, in saliva extracts ranged from 0.5-21 ng/mL with 59% between 2-6 ng/mL. These figures, for apparently healthy subjects, are higher than previously reported levels obtained by platelet assays. The validity of our radioimmunoassay results was checked by isolating and quantitating the PAF fraction from whole saliva. In addition, when we examined our saliva samples by platelet aggregation, low levels of PAF, comparable with the values found in the literature, were detected. Investigations revealed the presence of a substance(s) which inhibited PAF-induced platelet aggregation but which did not affect the radioimmunoassay.

Inhibitor(s) of Platelet-Activating Factor (PAF) in Human Saliva

“…The development of a specific and sensitive radioimmunoassay (RIA) for PAF (9) allows PAF to be accurately and routinely measured in various biological samples. Using the RIA, we quantitated PAF levels in numerous samples of mixed human saliva and found the levels to range from 0.5 to 21 ng/mL (10). These levels were higher than the previously reported data determined by bioassay {11,12) and higher than our results based on platelet aggregation measurements (10).…”

“…Using the RIA, we quantitated PAF levels in numerous samples of mixed human saliva and found the levels to range from 0.5 to 21 ng/mL (10). These levels were higher than the previously reported data determined by bioassay {11,12) and higher than our results based on platelet aggregation measurements (10).…”

“…In our previous study (10), PAF levels in whole saliva extracts were quantitated by RIA, and results indicated that there was sufficient PAF present in saliva to aggregate platelets. However, when measured by platelet aggregation, little PAF activity was found.…”

A specific, sensitive and high‐capacity immunoassay for PAF

“…As with saliva (6) and serum, it is anticipated that extraction of tissues and fluids with chloroform/methanol/water (9) will be a necessary step in preparing samples for examination by RIA. ed by the aggregation assay are much lower (6,10). Apart from the fact that losses are often likely to be greater during the sample preparation for platelet aggregation methods, interfering substances are clearly a problem with platelet-based assays (11)(12)(13)(14).…”

Διερεύνηση Της Ύπαρξης Του Παράγοντα Ενεργοποίησης Αιμοπεταλίων (PAF) Ή Άλλων Μεσολαβητών Σε Κυανοφύκη Σπηλαίων

“…Στην συνέχεια βρέθηκε ότι τα κύτταρα των περισσοτέρων ιστών έχουν την ικανότητα να συνθέτουν PAF σε φυσιολογικές αλλά και παθολογικές καταστάσεις µετά από διέγερση. Φυσική συνέπεια της δυνατότητας των κυττάρων να εκκρίνουν τον PAF που συνθέτουν, ήταν η ανίχνευσή του σε πολλά βιολογικά υγρά όπως στο πλάσµα (Cooney, S.J. et al 1991), ούρα (Sobhani, I. et al 1992), σάλιο (Billah, M.M.…”