1992 Fiscal Year Final Research Report Summary
Anesthetic effects on the physicochemical parameters and the functions of phase boundary of lipid membrane and macro-molecule
| Project/Area Number |
03304039
|
|---|
| Research Category |
Grant-in-Aid for Co-operative Research (A)
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
麻酔学
|
|---|
| Research Institution | KAGAWA MEDICAL SCHOOL |
|---|
Principal Investigator |
OGLI Kenji Kagawa Medical School Dept. of Anesthesiology & Emergency Medicine,Professor, 医学部, 教授 (40079934)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
YOKONO Satoshi Kagawa Medical School,Central Operating theater,Associate Professor, 医学部附属病院, 助教授 (70106425)
TANIGUCHI Yoshihiro Ritsumeikan Univ. Dept. of Science & Engineering, Professor, 理工学部, 教授 (70066702)
SHIBATA Akira The Univ. of Tokushima, Dept. of Pharmaceutical Science,Assosiate Professor, 薬学部, 助教授 (40035556)
TERADA Hiroshi The Univ. of Tokushima Dept. of Pharmaceutical Science,Professor, 薬学部, 教授 (00035544)
KANESHINA Shoji The Univ. of Tokushima Dept. of Engineering,Professor, 工学部, 教授 (80035617)
|
|---|
| Project Period (FY) |
1991 – 1992
|
| Keywords | Anesthetics / Mechanism / Membrane / Macro-Molecules / Interface |
|---|
| Research Abstract |
Anesthetics are not located in membrane core,but in interfacial region. On increasing the concentration, anesthetic molecules penetrate into the inside of membrane. By the application of Taft's polarity parameters to the spectral changes of probes incorporated in lipid membrane,it is revealed that anesthetics increase the H-bond acceptability and decrease the polarity at the interface. This effect can be explained by the release of hydrated water molecules from the membrane interface. Physicochemical properties concerning adsorption were also analyzed using charcoal. Alcohol and pressure synergistically induce the interdigitation in the lipid bilayer. This action of alcohol is not pressure reversible.
Partitioninng into the membrane and cutoff phenomena: The thermal phase transition of lipid membrane consists of pre-transition from gel II to gel I and main-transition from gel I to liquid phase. Anesthetics are known to depress the phase transition temperatures. This effect is more significant with respect to the pre-transition. Under the condition that anesthetic potency is proportional to its oil solubility,the partition coefficients of anesthetics to liquid phase;K(L) are larger than those to gel I phase;K(G). When the number of carbon atoms of anesthetics increases, K(G) becomes larger than K(L). This may be the reason to cause cutoff phenomena of anesthesia.
Effects on protein: Various informations about the effect of anesthetics upon the alpha-herix-beta-sheet transition of poly-L-lysine,and the activation of alpha-chymotrypsin were revealed.
Conclusion: Many reports dealt with the site specific action of anesthetics were published in these days. However,from our considerations, most of these data can be treated as the results of non-specific actions of anesthetics to the macro-molecules. More communications between researchers and more cooperative research projects are desired.
|
