Abstract
Epidermal growth factor (EGF) is synthesized in the kidneys and excreted in urine. Administration of exogenous EGF modulates the reabsorption of Na+ and the vasopressin stimulated reabsorption of water in the collecting tubules. In order to clarify whether this reflects a physiological role for urinary EGF we examined the effects of changes in the oral loads of water, Na+ and NH4+ as well as the effect of infusion of the vasopressin analogue, desmopressin (DDAVP) on the endogenous urinary EGF excretion in the rat. Water deprivation for 48 h reduced the urinary excretion of EGF by 25% and the urinary EGF/creatinine ratio by 8%. Also, urinary volume, Na+ excretion, and urinary pH were reduced by water deprivation. Infusion of DDAVP, low plasma vasopressin induced by polydipsia, and changes in the renal excretion of Na+ and H+ did not affect the urinary excretion of EGF. In conclusion: it seems unlikely that nephrogenous EGF excreted in the urine plays a physiological role in the regulation of the renal excretion of Na+ and H+ and in the vasopressin stimulated reabsorption of water in the rat. However, since water deprivation reduced the urinary excretion of EGF it remains possible that urinary EGF plays a role in the complex physiological response to dehydration.
| Original language | English |
|---|---|
| Journal | Regulatory Peptides |
| Volume | 44 |
| Issue number | 1 |
| Pages (from-to) | 17-24 |
| Number of pages | 8 |
| ISSN | 0167-0115 |
| Publication status | Published - 5 Mar 1993 |
Keywords
- Administration, Oral
- Ammonium Chloride
- Animals
- Deamino Arginine Vasopressin
- Epidermal Growth Factor
- Female
- Infusion Pumps
- Injections, Subcutaneous
- Rats
- Rats, Wistar
- Sodium
- Water
- Water Deprivation