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Toxicological information

Specific investigations: other studies

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Administrative data

Endpoint:
mechanistic studies
Type of information:
experimental study
Adequacy of study:
supporting study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: meets generally accepted scientific standards and is described in sufficient detail

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2006

Materials and methods

Test guideline
Qualifier:
no guideline followed
Principles of method if other than guideline:
Effects of AMP upon choline uptake by CHO cells were evaluated in actively growing cultures exposed to 3H-choline and a range of concentrations of AMP•HCl (0-32 mM; 0-4000 mg/L) for approximately
10 minutes.
GLP compliance:
no
Type of method:
in vitro
Endpoint addressed:
not applicable

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
AMP.HCL (approx 47% AMP)

Test animals

Species:
other: Chinese hamster ovary cells

Administration / exposure

Details on exposure:
Effects of AMP upon choline uptake by CHO cells were evaluated in actively growing cultures exposed to 3H-choline and a range of concentrations of AMP•HCl (0-32 mM; 0-4000 mg/L) for approximately 10 minutes
Analytical verification of doses or concentrations:
no
Duration of treatment / exposure:
10 minutes
Frequency of treatment:
once
Doses / concentrations
Remarks:
Doses / Concentrations:
0.8, 4, 8, 16, 24, and 32 mM (100, 500, 1000, 2000, 3000, and 4000 mg/L, respectively) in the first Trial and 0.8, 4, 8, 16, 32, 48, and 80 mM (100, 500, 1000, 2000, 4000, 6000, and 10000 mg/L, respectively) in the second trial
Basis:
nominal conc.
No. of animals per sex per dose:
not applicable

Results and discussion

Any other information on results incl. tables

A dose-response in cell viability versus concentration of AMP-HCl was observed in both toxicity trials. Survival relative to untreated controls ranged from 100+% to 61-68% over a concentration range of 0.04-32 mM. A 29% and 5.5% survival was noted at 48 and 80 mM, respectively, in trial II. The positive control consisting of 5% ethanol resulted in a survival of only 28-36% of untreated controls in both trials. No effects upon pH or osmolarity of the treated cultures were observed. Based upon these findings, a concentration range of 0.4 to 32 mM AMP-HCl was evaluated for effects upon 3H-choline uptake by CHO cells.

Uptake of 3H-Choline

There were no significant differences in protein content between treated and control cultures indicating no significant loss of cells in the 10-minute dosing period, including the high dose which resulted in cell numbers 61-68% of controls following 48 hours treatment. AMP-HCl was found to cause a dose-related decrease in 3H-choline uptake over the 40 to 80 fold concentration ranges examined; 0.8-32 mM in Choline Trial I and 0.4-32 mM in Choline Trial II. A statistically significant decrease in the uptake of 3H -choline was achieved at concentrations of 4 mM (65-81% of control) to 32 mM (30-36% of control) in both Trials. AMP-HCl appears to be a relative weak inhibitor of choline uptake in vitro with an approximate EC50 of 8.71-14.79 mM. It is approximately 10-17 fold less active than triethanolamine (EC50 ~0.89 mM), approximately 17-28 fold less active than diisopropanolamine (EC50 ~0.52 mM), and approximately 44-74 fold less active than diethanolamine (EC50 ~0.20 mM) in the same CHO cell based in vitro assay.

Applicant's summary and conclusion

Conclusions:
It was concluded that AMP-HCl has the potential to inhibit uptake of the essential nutrient choline in cultured CHO cells in the absence of significant toxicity. This activity, however, is relatively weak when compared to several other alcohol amines under similar assay conditions.