Background: The frog skin epithelium is used as a model to demonstrate the transport of various charged and non-charged solutes from the mucosal to serosal side through channels and transporters. The mucosal side, otherwise termed as the apical side or outer side, is the side which is exposed to the external environment (towards pond water). The serosal side, also known as the basolateral side, faces the internal environment of the organism.
Aims and Objectives: The objective of the present study is to determine the action of antidiuretic hormonal (ADH) on the movement of non-charged solutes such as urea and glycerol across the frog skin epithelium.
Materials and Methods: For this study, the ventral abdominal skin of frog, species Rana hexadactyla was mounted in an Ussings type chamber. Normal Ringers solutions containing urea (5 mM) and glycerol (90 mM) each were placed on the mucosal side, and ADH was added either on the mucosal side or the serosal side. After the addition of ADH, the colorimetric method was used to measure the transport of urea at the absorbance of 540nM and glycerol absorbance of 505 nM using a spectrophotometer; statistical analysis was done by Wilcoxon-Signed Ranks Test, all values were expressed as a mean ± standard error of means, n = 4.
Results: Addition of ADH (40 nM) on serosal side increased the urea transport from control 29.3 ± 5.1 μmol/dL to 52.3 ± 6.8 μmol/dl and increased glycerol transport from 34.8 ± 6.0 μmol/dL to 45.3 ± 6.6 μmol/dL, whereas addition of ADH on the mucosal side did not increase the glycerol transport, the control value was 14.6 ± 4.3 μmol/dL and with ADH that the value was 9.6 ± 2.9 μmol/dL.
Conclusion: The results concluded that the addition of ADH on serosal side enhanced the transport of urea and glycerol. Addition of ADH on the mucosal side did not show any effect on transport of glycerol.
Key words: Antidiuretic hormone, Aquaporin, Frog skin epithelium, Urea and Glycerol, Spectrophotometer
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