|
|
A study of the temperature sensitivity of the human TRPA1 channel
Barvíková, Kristýna ; Šulc, Miroslav (advisor) ; Černá, Věra (referee)
Transient receptor potential (TRP) ion channels play important physiological roles in the detection of environmental stimuli that occur primarily at the peripheral terminals of specialized sensory neurons. The recently resolved cryo-electron microscopy structures and molecular biological techniques have provided new tools that enable to study these channels in relation to their function, and thus to understand more deeply their pharmacology and physiology. The aim of this bachelor thesis is to give an overview of the current status of research on the ankyrin TRP channel subtype 1 (TRPA1), a channel activated by diverse irritant chemical stimuli but also by temperature changes. The experimental part is focused on the elucidation of the role of the sensor domain in thermal sensitivity of the TRPA1 channel. Using whole-cell patch-clamp electrophysiological technique, the presented results demonstrate that the sensor is an important determinant of voltage-dependent gating. Mutation of the conserved tyrosine in the center of the sensor resulted in channels with clearly different activation kinetics and increased chemical responses upon increasing the temperature from 25 řC to 35 řC. Key words: TRP ion channel, ankyrin receptor, nociception, structure-function, carvacrol
|
|
|
Determination of selected terpenoids by HPLC with electrochemical detection
Mužíková, Jana ; Dejmková, Hana (advisor) ; Schwarzová, Karolina (referee)
This thesis deals with the determination of carvacrol, thymol, and eugenol by HPLC with electrochemical detection. Carbon paste electrode and boron doped diamond film electrode were used as the working electrodes. For the comparison, UV spectrophotometric detection at 275 nm was used besides the electrochemical detection. The separation was performed on LiChroCART 125-4, RP-18e (5 µm) column. Optimum separation conditions were found: mobile phase consisting of acetonitrile and acetate buffer in ratio 50:50, the optimum buffer pH was pH 5. The optimum potential of working electrode during electrochemical detection was +0,8 V and +1,2 V for carbon paste electrode and boron doped diamond film electrode, respectively. For both electrodes, repeatability of the measurement was examined; the surface of both electrodes had to be renewed between the measurements. Under the obtained optimum conditions, calibration dependences were measured. The studied substances were determined in real samples, in Thymus vulgaris L. and Achillea millefolium L. and in thyme-containing tea and syrup.
|
|
|
Determination of carvacrol using HPLC with electrochemical detection
Mužíková, Jana ; Dejmková, Hana (advisor) ; Schwarzová, Karolina (referee)
This thesis deals with determination of a mixture of carvacrol with thymol and eugenol by HPLC with electrochemical detection. Carbon paste electrode was used as the working electrode. The separation was performed on Kromasil-C18, 250x4,6 mm column. For the comparison, UV spectrophotometric detection at 275 nm was used besides electrochemical detection. Optimal separation conditions were found: mobile phase consisting of acetonitrile and phosphate buffer in ratio 60:40, the optimal buffer pH was pH 4. As the optimum potential of working electrode during electrochemical detection, potential +1.1 V was found. Under the obtained optimal conditions, calibration dependences were measured. Limit of quantification for carvacrol was found to be 9,6·10-7 mol dm-3 using UV spectrophotometric detection and 4,0·10-8 mol dm-3 using electrochemical detection.
|
|
|
A study of the temperature sensitivity of the human TRPA1 channel
Barvíková, Kristýna ; Šulc, Miroslav (advisor) ; Černá, Věra (referee)
Transient receptor potential (TRP) ion channels play important physiological roles in the detection of environmental stimuli that occur primarily at the peripheral terminals of specialized sensory neurons. The recently resolved cryo-electron microscopy structures and molecular biological techniques have provided new tools that enable to study these channels in relation to their function, and thus to understand more deeply their pharmacology and physiology. The aim of this bachelor thesis is to give an overview of the current status of research on the ankyrin TRP channel subtype 1 (TRPA1), a channel activated by diverse irritant chemical stimuli but also by temperature changes. The experimental part is focused on the elucidation of the role of the sensor domain in thermal sensitivity of the TRPA1 channel. Using whole-cell patch-clamp electrophysiological technique, the presented results demonstrate that the sensor is an important determinant of voltage-dependent gating. Mutation of the conserved tyrosine in the center of the sensor resulted in channels with clearly different activation kinetics and increased chemical responses upon increasing the temperature from 25 řC to 35 řC. Key words: TRP ion channel, ankyrin receptor, nociception, structure-function, carvacrol
|
|
|
Determination of selected terpenoids by HPLC with electrochemical detection
Mužíková, Jana ; Dejmková, Hana (advisor) ; Schwarzová, Karolina (referee)
This thesis deals with the determination of carvacrol, thymol, and eugenol by HPLC with electrochemical detection. Carbon paste electrode and boron doped diamond film electrode were used as the working electrodes. For the comparison, UV spectrophotometric detection at 275 nm was used besides the electrochemical detection. The separation was performed on LiChroCART 125-4, RP-18e (5 µm) column. Optimum separation conditions were found: mobile phase consisting of acetonitrile and acetate buffer in ratio 50:50, the optimum buffer pH was pH 5. The optimum potential of working electrode during electrochemical detection was +0,8 V and +1,2 V for carbon paste electrode and boron doped diamond film electrode, respectively. For both electrodes, repeatability of the measurement was examined; the surface of both electrodes had to be renewed between the measurements. Under the obtained optimum conditions, calibration dependences were measured. The studied substances were determined in real samples, in Thymus vulgaris L. and Achillea millefolium L. and in thyme-containing tea and syrup.
|
|
|
Determination of carvacrol using HPLC with electrochemical detection
Mužíková, Jana ; Schwarzová, Karolina (referee) ; Dejmková, Hana (advisor)
This thesis deals with determination of a mixture of carvacrol with thymol and eugenol by HPLC with electrochemical detection. Carbon paste electrode was used as the working electrode. The separation was performed on Kromasil-C18, 250x4,6 mm column. For the comparison, UV spectrophotometric detection at 275 nm was used besides electrochemical detection. Optimal separation conditions were found: mobile phase consisting of acetonitrile and phosphate buffer in ratio 60:40, the optimal buffer pH was pH 4. As the optimum potential of working electrode during electrochemical detection, potential +1.1 V was found. Under the obtained optimal conditions, calibration dependences were measured. Limit of quantification for carvacrol was found to be 9,6·10-7 mol dm-3 using UV spectrophotometric detection and 4,0·10-8 mol dm-3 using electrochemical detection.
|
guest ::
