Lipase, triacylglycerol

Developmental toxicity / teratogenicity

Administrative data

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: The study was performed before formal guidelines but according to best practice at that time, and according to GLP .

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1986

Report date:

1986

Materials and methods

Test guideline

Qualifier:

no guideline available

Principles of method if other than guideline:

The study was perfermed before any formal guidelines but according to best practice at that time.

GLP compliance:

yes (incl. QA statement)

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Active enzyme protein of Lipase, triacylglycerol (EC no. 232-619-9, CAS no. 9001-62-1, EC name: Lipase, triacylglycerol, Enzyme Class No.: 3.1.1.3)

Cas Number:

9001-62-1

Molecular formula:

Not applicable, see remarks

IUPAC Name:

Active enzyme protein of Lipase, triacylglycerol (EC no. 232-619-9, CAS no. 9001-62-1, EC name: Lipase, triacylglycerol, Enzyme Class No.: 3.1.1.3)

Constituent 2

Reference substance name:

Protein as a constituent of enzyme deriving from the fermentation or extraction process

Molecular formula:

Not available

IUPAC Name:

Protein as a constituent of enzyme deriving from the fermentation or extraction process

Constituent 3

Reference substance name:

Inorganic salts as a constituent of enzyme deriving from the fermentation or extraction process

Molecular formula:

Not available. See remarks.

IUPAC Name:

Inorganic salts as a constituent of enzyme deriving from the fermentation or extraction process

Constituent 4

Reference substance name:

Carbohydrates constituent of enzyme deriving from the fermentation or extraction process

Molecular formula:

Not available. See remarks.

IUPAC Name:

Carbohydrates constituent of enzyme deriving from the fermentation or extraction process

Constituent 5

Reference substance name:

Lipids as a constituent of enzyme deriving from the fermentation or extraction process

Molecular formula:

Not available. See remarks.

IUPAC Name:

Lipids as a constituent of enzyme deriving from the fermentation or extraction process

Test material form:

solid: particulate/powder

Remarks:

powder

Details on test material:

- Lot/batch No.: PPW 1798
- Expiration date of the lot/batch: December 1996

Test animals

Species:

rat

Strain:

Sprague-Dawley

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River (UK) Limited, Manston, Kent, UK.
- Age at study initiation: 8-9 weeks
- Weight at study initiation: 162-219 g
- Housing: 2 per cage.
- Diet (e.g. ad libitum): Rat and Mouse Breeder Diet No. 3 SQC Expanded (ground) ad libitum
- Water : domestic water ad libitum
- Acclimation period: 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20°C ± 2°C
- Humidity (%): 55% ± 10%
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:

oral: feed

Vehicle:

other: Diet without test substance

Details on exposure:

DIET PREPARATION
- Rate of preparation of diet: Fresh diet batches were prepared weekly during the study, each dose level being prepared independently.
- Mixing appropriate amounts of lipase with the rat diet to following dose levels, 0, 2, 5 and 10 % in the diet.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Samples were removed from each mixed batch of diet and despatched to the Sponsor for analysis of enzyme activity in lipase units/g.

Details on mating procedure:

108 female rats arrived timed-mated on day 1 of gestation at the research lab.

Duration of treatment / exposure:

12 days (day 6 - day 17 of gestation).

Frequency of treatment:

The diet contained a constant concentration of test material and was available ad libitum.

Duration of test:

The animals had access to treated diet from day 6 - day 17 of gestation (day 0 = day of verification of copulatory plug in situ).

No. of animals per sex per dose:

27 mated females

Control animals:

yes, plain diet

Examinations

Maternal examinations:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: During each day

BODY WEIGHT: Yes, at day 1, 6, 9, 13, 17 and 20 of gestation

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study):
- Food consumption for each cage determined daily
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: No

Ovaries and uterine content:

On day 20, the animals were killed by nitrogen asphyxiation. The reproductive tract was dissected out, weighed and then examined.

Fetal examinations:

- External examinations: Yes all per litter
- Soft tissue examinations: Yes, 1/3 of the foetuses by free-hand sectioning (Wilson), while the other 2/3 were fixed for gross visceral abnormalities.
- Skeletal examinations: Yes, 2/3 of the foetuses
- Head examinations: Yes, 2/3 of the foetuses
Number of implants were recorded, if they were alive or dead (late vs early)

Statistics:

Body weight and foetal weight data were subjected to analysis of variance, using the Normal linear model for a one-way classification. Treatments were then compared using Dunnett’s t test.

Results and discussion

Results: maternal animals

Maternal developmental toxicity

Details on maternal toxic effects:

Maternal toxic effects: Yes

Details on maternal toxic effects: Slight reductions in maternal body weight gain and food consumption occurred at the 10% lipase dose level only

Results (fetuses)

Details on embryotoxic / teratogenic effects:

Embryotoxic / teratogenic effects: Yes

Details on embryotoxic / teratogenic effects: At 5% and 10% lipase in the diet, there was a very slight reduction in foetal weight, together with some other evidence of slight immaturity amongst parameters of skeletal ossification state and in growth of the viscera of a small number of fetuses.

Effect levels (fetuses)

Key result

Dose descriptor:

NOAEL

Effect level:

other: >= 2% lipase by weight in the diet

Based on:

test mat.

Basis for effect level:

other: teratogenicity

Applicant's summary and conclusion

Conclusions:

Maternal effect of treatment in this study were slight reductions in weight gain and food consumption at 10% lipase in the diet.

At 5% and 10% lipase in the diet, there was a very slight reduction in foetal weight, together with some other evidence of slight immaturity amongst parameters of skeletal ossification state and in growth of the viscera of a small number of fetuses.

It was concluded that, under the conditions of this study, dose levels of 5% and 10% lipase by weight in the diet caused slight growth retardation of fetuses, while slight maternal toxicity was confined to the 10% lipase dose level.

No significant effect was considered to have occurred at a dose level of 2% lipase by weight in the diet. No teratogenic potential of lipase was demonstrated at any dose level up to 10% lipase by weight in the diet.

Executive summary:

Lipase, batch PPW 1798 was used for teratogenicity testing in rats.

 

Mated Sprague-Dawley rats were randomized into 3 treatment groups and one control group, each group containing 27 animals. These animals were exposed continuously to test diets from Day 6 to Day 17 of gestation, where Day 0 was the day of verification of mating by detection of a copulatory plug in situ. Dose levels applied were as follows:

 

	% lipase by Weight in the Diet
Control Low dose Intermediate dose High dose	0 2 5 10

 

It was concluded that, under the conditions of this study, dose levels of 5% and 10% lipase in the diet caused slight growth retardation of fetuses, while slight reductions in maternal body weight gain and food consumption occurred at the 10% lipase dose level only.

No significant effect was considered to have occurred at the 2% lipase level.

No teratogenic potential of lipase was demonstrated at any of the dose levels used.