ABSTRACT
The present study was carried out to investigate the effect of colour pigments used for painting the decorative articles like idols, on the freshwater bivalve, Lamellidens marginalis. The effects of sub-chronic exposure were studied by the changes in the biochemical constituents like total protein, glycogen and lactic acid, in different tissues like muscle, mantle, gills, foot, hepatopancreas and gonads for 10 and 20 days period. The glycogen contents in the muscle, mantle and gonads were significantly decreased with increase in concentration of colour pigments. It decreased from 26.77 mg gm-1 in control to 19.17 mg gm-1 at 900 ppm after 20 days of exposure; whereas protein contents in the tissues studied decreased significantly from 22.5 mg gm-1 in control to 15.5 mg gm-1 at 900 ppm after 10 days of exposure. The increase in lactic acid content in all the tissues except gills and gonads may be due to acute hypoxia.
ABSTRACT
On the buffalo ureter, histamine did not elicit any direct effect. However, it caused concentration-dependent relaxation of the tissues precontracted by carbachol, phenylephrine, norepinephrine, KCI or BaCl2 and also inhibited the contractile effect of carbachol. Metiamide selectively antagonised the relaxation and inhibition of contractile response but mepyramine did not show this effect. Isoprenaline, dobutamine, salbutamol, verapamil and papaverine neither produced any direct effect nor relaxed the carbachol-contracted tissues; norepinephrine and epinephrine had contractile effects. Hence, the histamine-induced relaxation was mediated through the activation of H2 receptors and not through adrenergic mechanisms or blockade of Ca(2+)-channels or inhibition of cyclic nucleotide phosphodiesterase.