Changes of phospholipase D activity of rat peritoneal mast cells in degranulation.

Aim: To study the changes of phospholipase D (PLD) activity of actively sensitized rat peritoneal mast cells (RPMC) in degranulation.

Methods: Degranulation of RPMC was determined by measurement of beta-hexosaminidase release. PLD activity assay was carried out by measurement of PLD product, choline, with chemiluminescent oxidation of luminol.

[Role of phospholipase D in priming of rat peripheral leukocytes by lipopolysaccharide and antigen].

Objective: To investigate whether or not lipopolysaccharide (LPS) and ovalbumin (OA) prime rat peripheral leukocytes, the effect of sensitization on priming and the role of phospholipase D in priming.

Methods: The peripheral leukocytes were separated and purified from sensitized or unsensitized rats. LPS or OA was used as a priming agent and formylmethionylphenylalanine (fMLP) as an activating agent.

[Cyclic nucleotides phosphodiesterase activity in a rat lung model of asthma].

OBJECTIVE: To assess the change of cGMP-PDE and cAMP-PDE activity in a rat lung model of asthma. METHODS: cGMP-PDE and cAMP-PDE activity were determined by HPLC. RESULTS: Both cAMP-PDE activity and cGMP-PDE activity in the lung tissue of antigen-challenged rats were higher than that from the normal rats (P <0.