Pathways and quantification of insoluble particles in the lung compartments of the rat.

The aim of this investigation was focused on mechanisms involved in toxicokinetics of particles and fibers within the rat lung. Biologically inert polystyrene particles or an asbestos--particle comixture were followed in their pathways of deposition and retention in the lung, particularly in the alveolar space and their accumulation in the lymph node tissue of exposed rats. One group of Wistar rats was intratracheally instilled with 0.

The role of intratracheal instillation and bronchoalveolar lavage in the investigation of mechanisms underlying lung disorders--an animal model.

When studying the course and etiopathological mechanisms underlying human lung disorders caused by external factors, it is extremely important to extend the investigations by using an experimental animal model. The advantage of such a model, in respect to well-known ethical limits involved in a human study. Is that one can precisely design the experiment, keep the relevant parameters under strict control and limtate the pathological conditions to be studied.

The rate of DNA synthesis in HeLa cells during combined long-term and acute exposures to lead.

Asynchronous populations of HeLa cells growing as monolayers were incubated in a nutritive medium supplemented with a low concentration of 10(-5) M lead chloride for several months. At various time intervals the [3H]thymidine uptake was measured in the DNA of the cells by a scintillation counting technique. During the first 2 weeks of incubation, the rate of DNA synthesis was slightly reduced.

[Lead and cadmium toxicity in established mammalian cell lines].

Lead and cadmium toxicity was evaluated in three mammalian cell lines (tumour : HeLa, transformed : XC and normal : NRK) by means of the modifications of the 3H-TdR incorporation rate in the nucleus of the treated cells. The three cell lines showed different degrees of sensitivity. Sensitivity depended on the line, metal, its concentration and duration of incubation.