From frog skin to human colon: rapid responses to steroid hormones

New research on steroid hormone action in the human colon and kidney could pave the way for novel therapeutic targets for the treatment of hypertension and diarrhoea.

Prof Brian Harvey at University College Cork has been studying how the hormones oestrogen and aldosterone produce rapid changes in the transport of salt and water through human intestines and kidneys. Human beings have two main organs that regulate the body’s salt and water balance (effectively blood pressure) – the kidney and the intestines. When the transport of salt and water is poorly regulated, such as in diarrhoea or kidney failure, the consequences can be fatal. Prof Harvey has identified novel receptors for hormones that control whole body fluid balance, although currently these receptors have only been found in female tissues. The hope is that steroids that lock into these receptors could be used to treat illnesses like high blood pressure and diarrhoea.

Prof Harvey has also been studying the effects of steroid hormones in frog skin because the animal uses it skin to absorb salt and water just like a human kidney, hence frog skin acts as a classical model for kidney studies. He will present the results of his study at the Society for Experimental Biology conference on Tuesday 9 April. His work has shown that oestrogen can exert a protective (anti-secretory) effect to reduce fluid loss following exposure to cholera toxin or heat-stable enterotoxin (food poisoning).