Skip to main content
Environmental Sciences Europe

Table 1 Mass balances of applied dose and kinetic parameters of caffeine and testosterone permeation across the skin of Xenopus laevis

From: Adaption of a dermal in vitro method to investigate the uptake of chemicals across amphibian skin

Test compound

Caffeine

Testosterone

Exposure time

4 h

8 h

Skin

Fresh

Frozen

Fresh

Frozen

Dorsal (5)

Ventral (4)

Dorsal (5)

Ventral (5)

Dorsal (3)

Ventral (3)

Dorsal (3)

Ventral (3)

Non-absorbed dose [%]

5.7 ± 1.8

3.4 ± 0.3

1.4 ± 0.8

1.0 ± 0.9

12.9 ± 5.3

9.6 ± 1.8

21.5 ± 4.1

17.0 ± 10.1

Skin content [%]

20.6 ± 4.0 (2)

6.2 (1)

4.1 ± 1.2 (2)

–

16.5 ± 1.9

9.2 ± 5.0

9.5 ± 1.4

7.5 ± 3.5

Absorbed dose [%]

71.4 ± 2.2

87.5 ± 1.2

88.4 ± 5.0

90.3 ± 5.6

69.0 ± 3.3

84.8 ± 5.7

66.5 ± 6.3

75.2 ± 15.0

Recovery [%]

95.8 ± 2.0 (2)

97.9 (1)

98.1 ± 1.9 (2)

–

98.3 ± 3.6

103.6 ± 4.8

97.5 ± 2.6

99.8 ± 1.9

maxAR [µg/(cm2 × h)]

12.1 ± 1.2

19.0 ± 2.7

25.5 ± 7.2

26.8 ± 5.7

5.3 ± 0.5

12.0 ± 5.6

7.4 ± 1.3

11.4 ± 5.5

maxKp [×10−3 cm/h]

3.0 ± 0.3

4.7 ± 0.5

6.2 ± 1.5

6.7 ± 1.4

1.3 ± 0.1

3.0 ± 1.4

1.9 ± 0.3

2.9 ± 1.4

  1. Mean values as percent of applied dose ± standard deviation based on n skin samples (n = 3–5, noted in brackets behind indication of skin site), stemming from two animals each [except for testosterone data of freshly excised skin due to separation of testosterone results into 4- and 8-h exposure studies; see (Additional file 1) for 4-h testosterone data and detailed information on the individual skin samples]
  2. non-absorbed dose first and second skin washings and extraction of donor chamber, skin content amount recovered from the washed, digested skin, absorbed dose in receptor medium at exposure end and extraction of receptor chamber; recovery represents the sum of non-absorbed dose, skin content, and absorbed dose, maxAR maximum absorption rate, maxKp maximum permeability coefficient, calculated as described in “Methods” section
Back to article page