cis-4-[3-(p-tert-butylphenyl)-2-methylpropyl]-2,6-dimethylmorpholine

Specific investigations: other studies

Administrative data

Endpoint:

biochemical or cellular interactions

Type of information:

experimental study

Adequacy of study:

other information

Study period:

1980

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1980

Report date:

1980

Materials and methods

Principles of method if other than guideline:

In-vitro study on acetylcholinesterase activity inhibition with plasma from rat and dog and pure AChE using structural analogues of the parent and a metabolite. I50 determinaton for most potent inhibitor.

GLP compliance:

no

Type of method:

in vitro

Endpoint addressed:

neurotoxicity

Test material

Test material information

Constituent 1

Specific details on test material used for the study:

Storage with silica gel at 4-10°C

Administration / exposure

Vehicle:

other: 50 mM phosphate buffer pH 7.2

Details on study design:

Results are a mean of ten measurements

The negative control was performed by adding water instead of the test substance.

The three test substances were each applied at a concentration of 4 mM.
Two test substances were structural analogues to a metabolite of the target substance.
One test substance was a structural analogue to the target substance.

The analogues were chosen to retain the structural groups considered relevant for AChE activity. The target substance itself could not be tested as such as it lacked sufficient solubility. There was no method to synthesize the metabolite.

Examinations

Examinations:

Cholinesterase activity was determined using a kit by Boehringer Mannheim, Germany which is based on the Elman method. Acetylthiocholine iodide is used as substrate and 5,5´-dithiobisnitrobenzoic acid (0.25 mmol/l) as indicator. The test is performed at 25°C.
The substrate concentrations applied were from 0.00001 to 0.01 mol/L.

Results and discussion

Details on results:

The analogue to the target substance did not inhibit rat and dog plasma cholinesterase activity and had a slight inhibitory effect on electrophorus electricus AChE activity.

Both metabolite analogues had a significant inhibitory effect on rat and dog (ca -65%) and on electrophorous electricus (ca - 82%) AChE activity.

The I50 concentrations were 3.5 mM for e.e. AChE and 0.425 mM for plasma AChE. The test substances are reversible competitive inhibitors of AChE.