0000000000466434
AUTHOR
S. D’angelo
Relationship between lanthanide contents in aquatic turtles and environmental exposures
International audience; Trace elements released in the environment during agricultural practices can be incorporated and accumulated in biological fluids and tissues of living organisms. The assessment of these exposures were carried out investigating lanthanide distributions in blood and exoskeleton samples collected from Emys trinacris turtle specimens coming from sites with anthropogenic discharge in western and south Sicily, along migration paths of many bird species from Africa to Europe. The data show a significant (Rxy = 0.72; Rxy > 0.67; α = 0.025) linear relationship between the size of turtle specimens and the lanthanide contents in blood lower than 0.4 μg L−1 whereas this relatio…
Tonic inhibitory action by nitric oxide on spontaneous mechanical activity in rat proximal colon: involvement of cyclic GMP and apamin-sensitive K+ channels
The cellular mechanisms by which endogenous nitric oxide (NO) modulates spontaneous motility were investigated in rat isolated proximal colon. The mechanical activity was detected as changes in intraluminal pressure. Apamin (1–100 nM) produced a concentration-dependent increase in the amplitude of the spontaneous pressure waves. The maximal contractile effect was of the same degree as that produced by Nω-nitro-L-arginine methyl ester (L-NAME) (100 μM) and the joint application of apamin plus L-NAME had no additive effects. Apamin (0.1 μM) reduced the inhibitory effects (i.e. reduction in the amplitude of the pressure waves) induced by sodium nitroprusside (SNP) (1 nM–10 μM) or 8-Br-cyclic G…
Modulation by nitric oxide of spontaneous mechanical activity in rat proximal colon.
Summary 1 In order to examine the role of nitric oxide (NO) in the tonic neural inhibition in rat proximal colon, the effects of Nω-nitro- l-arginine methyl ester (L-NAME) were studied on the spontaneous contractions of circular muscle (monitored as intraluminal pressure changes) and of longitudinal muscle (detected as isometric tension changes). 2 L-NAME (3 × 10−−6–3 × 10−−4 m) caused a concentration-dependent increase in the amplitude of circular contractions, without affecting those of longitudinal muscle. This effect was prevented by l-arginine (1–5 × 10−−3 m), but not d-arginine. 3 In the presence of tetrodotoxin (10−−6 m), which per se induced increase of the pressure waves, L-NAME (1…