Papers by CARLOS LOPEZ MENDOZA
Life Sciences, 2008
Aims: Although 5-hydroxytryptamine (5-HT) contracts airway smooth muscle in many mammalian specie... more Aims: Although 5-hydroxytryptamine (5-HT) contracts airway smooth muscle in many mammalian species, in guinea pig and human airways 5-HT causes a contraction followed by relaxation. This study explored potential mechanisms involved in the relaxation induced by 5-HT. Main methods: Using organ baths, patch clamp, and intracellular Ca 2+ measurement techniques, the effect of 5-HT on guinea pig airway smooth muscle was studied. Key findings: A wide range of 5-HT concentrations caused a biphasic response of tracheal rings. Response to 32 μM 5-HT was notably reduced by either tropisetron or methiothepin, and almost abolished by their combination. Incubation with 10 nM ketanserin significantly prevented the relaxing phase. Likewise, incubation with 100 nM charybdotoxin or 320 nM iberiotoxin and at less extent with 10 μM ouabain caused a significant reduction of the relaxing phase induced by 5-HT. Propranolol, L-NAME and 5-HT 1A , 5-HT 1B /5-HT 1D and 5-HT 2B receptors antagonist did not modify this relaxation. Tracheas from sensitized animals displayed reduced relaxation as compared with controls. In tracheas precontracted with histamine, a concentration response curve to 5-HT (32, 100 and 320 μM) induced relaxation and this effect was abolished by charybdotoxin, iberiotoxin or ketanserin. In single myocytes, 5-HT in the presence of 3 mM 4-AP notably increased the K + currents (I K(Ca) ), and they were completely abolished by charybdotoxin, iberiotoxin or ketanserin. Significance: During the relaxation induced by 5-HT two major mechanisms seem to be involved: stimulation of the Na + /K + -ATPase pump, and increasing activity of the high-conductance Ca 2+ -activated K + channels, probably via 5-HT 2A receptors.
Measurement Science & Technology, 2003
Three-dimensional twin-pulsed digital holography is used to separate the x, y and z displacement ... more Three-dimensional twin-pulsed digital holography is used to separate the x, y and z displacement components in a rotating disc. The technique is able to distinguish the rotation and displacement movement along the xy plane from the out-of-plane z displacement. The results show that three-dimensional twin-pulsed digital holography may be used to derotate the object by combining information from three different illumination positions.
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Papers by CARLOS LOPEZ MENDOZA