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Urban air particulates (suspended particles and settling dust), furthermore dust emitted by a Soderberg aluminum reduction plant and a coal burning power plant from an industrial town, Ajka (30,000 inhabitants) were analysed for PAH content (liquid chromatography) and mutagenicity (Salmonella microsome test). Air particulates from Papa--a town of similar size without considerable heavy industry--and corresponding plant emission from Inota, a third town in the study, served as controls. The dust content and the PAH concentration, as well as the mutagenic potency of the air in Ajka were higher than in Papa. Mutagenicity of the airborne particulates showed a clear seasonality with a winter maximum and a summer minimum in both towns. The mutagenic potency of air correlated well with the air BaP and total PAH content in Ajka, but not in Papa. The amounts of extractable organic material and mutagenic potency as calculated for unit quantity of airborne particulate matter was higher in the Papa samples. Similar differences between the two towns were observed in the case of fallen dust, too. On the basis of examination of emitted dust, it can be stated, that in the mutagenicity of urban air, the aluminum plant emission plays a considerably higher role than the power plant emission, which is the main component of air dust pollution in Ajka.

The effect of dopamine receptor stimulation by administration of the dopamine analogue bromocriptine on Met-enkephalin-LI was examined in rat hypothalamus, and neurointermediate and anterior lobes of pituitary. Bromocriptine treatment resulted in a dramatic decline of Met-enkephalin-LI in neurointermediate pituitary which was significant by 3 days of treatment. Maximal reduction of Met-enkephalin-LI ranged between 60-70% of pretreatment values and was maintained as long as bromocriptine was administered (4 weeks), with no evidence of desensitization or "escape." The effects of bromocriptine on neurointermediate lobe were of long duration and persisted for at least 4 days after discontinuation of treatment. No significant effects of bromocriptine were detected on Met-enkephalin-LI in hypothalamus or anterior pituitary. Whether these differences represent truly different regional regulation of Met-enkephalin-LI or whether the changes are more sensitively reflected in an area such as neurointermediate lobe that largely consists of nerve terminals, remains to be shown.