scholarly journals The effect of auxins (IAA and 4-Cl-IAA) on the redox activity and medium pH of Zea mays L. root segments

2006 ◽  
Vol 11 (3) ◽  
Author(s):  
Halina Lekacz ◽  
Waldemar Karcz
Keyword(s):  
Acetic Acid ◽  
Dose Response ◽  
Zea Mays L ◽  
Response Surfaces ◽  
Redox Activity ◽  
Response Curves ◽  
Medium Ph ◽  
Ph Changes ◽  
Root Segments ◽  
Indole 3 Acetic Acid

AbstractIndole-3-acetic acid (IAA) and 4-chloroindole-3-acetic acid (4-Cl-IAA) were tested at different concentrations and times for their capacity to change the redox activity and medium pH of maize root segments. The dose-response surfaces (dose-response curves as a function of time) plotted for redox activity and changes in medium pH (expressed as ΔpH) had a similar shape for both auxins, but differed significantly at the optimal concentrations. With 4-Cl-IAA, the maximal values of redox activity and medium pH changes were observed at 10−10 M, which was a 100-fold lower concentration than with IAA. Correlations were observed between redox activity and medium pH changes at the optimal concentrations of both IAA and 4-Cl-IAA. The results are discussed herein, taking into account both the concentration of the auxins and the effects produced by them.

scholarly journals THE ADDITIVITY ANTINOCICEPTIVE INTERACTIONS BETWEEN DICLOFENAC AND THE DERRIS SCANDENS EXTRACT DRUG IN MICE.

2018 ◽  
Vol 11 (1) ◽  
pp. 314
Author(s):  
Tadsanee Punjanon
Keyword(s):  
Acetic Acid ◽  
Side Effects ◽  
Combination Therapy ◽  
Dose Response ◽  
Pain Treatment ◽  
Fixed Ratio ◽  
Drug Dose ◽  
Response Curves ◽  
Interaction Index ◽  
Abdominal Constriction

 Objective: Combination therapy is a valid approach in pain treatment, in which a reduction of doses could reduce side effects and still achieve optimal analgesia. The objective was to determine the effects of coadministered diclofenac and the Derris scandens extract drug.Methods: Acetic acid-induced abdominal constriction test in mice was used to determine the type of interaction between components. The effective dose that produced 50% antinociception (ED50) was calculated from the log dose-response curves of fixed ratio combinations of diclofenac with the D. scandens extract drug. The ED50 was compared to the theoretical additive ED50 calculated from the ED50 of diclofenac and of the D. scandens extract drug alone.Results: Diclofenac and the D. scandens extract drug dose‐dependently and significantly reduced the abdominal writhing. The combination was the additive effect, the experimental ED50 being smaller than the theoretically calculated ED50. Interaction index of the combination was 0.89.Conclusion: The present study demonstrates the additivity antinociceptive interactions between diclofenac and the D. scandens extract drug and may be used as a combination analgesic in the treatment of pain conditions.

Differential temperature dependence of taste nerve responses to various taste stimuli in dogs and rats

1991 ◽  
Vol 261 (6) ◽  
pp. R1402-R1408 ◽  
Author(s):  
M. Nakamura ◽  
K. Kurihara
Keyword(s):  
Acetic Acid ◽  
Temperature Dependence ◽  
Temperature Change ◽  
Dose Response ◽  
Monosodium Glutamate ◽  
Taste Receptor ◽  
Chorda Tympani ◽  
Chorda Tympani Nerve ◽  
Response Curves ◽  
Tonic Response

The temperature dependence of the canine and rat chorda tympani nerve responses to various taste stimuli was examined. The temperature dependence greatly varied with species of stimuli. In the dog, the tonic responses to fructose, sucrose, acetic acid, and guanosine 5'-monophosphate (GMP) and the response induced by the synergism between monosodium glutamate (MSG) and GMP showed peaks at approximately 30 degrees C, whereas those to NaCl, NH4Cl, and MSG showed peaks between 10 and 20 degrees C. In the rat, the tonic response to NH4Cl increased with an increase in temperature up to 45 degrees C, whereas the responses to other stimuli examined showed peaks at approximately 30 degrees C. The responses to glycine, sucrose, and quinine showed sharp temperature dependence, and the responses to acids (HCl and acetic acid) and salts (NaCl and KCl) showed relatively flat dependence. The effects of the temperature change on dose-response curves for fructose, NH4Cl, and GMP were examined using dogs. The temperature change did not practically affect the thresholds for these stimuli and affected the magnitude of the responses to higher concentrations of stimuli. The origins of the temperature dependence were discussed in terms of taste receptor mechanisms.

Metabolism of [14C]indole-3-acetic acid by the cortical and stelar tissues of Zea mays L. roots

Planta ◽  
1985 ◽  
Vol 164 (1) ◽  
pp. 105-108 ◽  
Author(s):  
H. M. Nonhebel ◽  
J. R. Hillman ◽  
A. Crozier ◽  
M. B. Wilkins
Keyword(s):  
Zea Mays ◽  
Acetic Acid ◽  
Zea Mays L ◽  
Indole 3 Acetic Acid

Organolead Toxicity in Plants: Triethyl Lead (Et3Pb+) Acts as a Powerful Transmembrane Cl-/OH- Exchanger Dissipating H+ -Gradients at Nano-Molar Levels

1987 ◽  
Vol 42 (9-10) ◽  
pp. 1116-1120 ◽  
Author(s):  
A. Hager ◽  
I. Moser ◽  
W. Berthold
Keyword(s):  
Cell Wall ◽  
Acetic Acid ◽  
Avena Sativa ◽  
Zea Mays L ◽  
Tetraethyl Lead ◽  
Intact Cells ◽  
Triethyl Lead ◽  
Plant Membranes ◽  
Energy Dependent ◽  
Indole 3 Acetic Acid

Triethyl lead (Et3Pb+), a highly toxic oxidation product of the anti-knock agent tetraethyl lead (Et4Pb) was shown to act as anion (Cl-/OH-) antiporter in plant membranes, dissipating energy- dependent ion gradients, membrane potentials, and consequently turgor. This mechanism was demonstrated with tonoplast-type vesicles isolated from coleoptiles of Zea mays L. The ATP- driven H+ accumulation within those vesicles was abolished already at nano-molar levels of Et3Pb+, but only in the presence of Cl-. In intact cells the turgor dependent indole-3-acetic acid induced elongation growth of coleoptile segments of Avena sativa L. was inhibited by Et3Pb+ at micro-molar levels and after a lag of 15-20 min. This lag might be due to a slow penetration of the agent through the waxy cuticle and the cell wall.

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