Localisation by immunofluorescence of thyrotropin-releasing hormone in the cutaneous glands of the frog, Rana ridibunda.

Using the technique of indirect immunofluorescence, thyrotropin-releasing hormone (TRH) has been localised in certain cells of the cutaneous glands of the frog, $\text{Rana ridibunda}$. No specific fluorescence was found in other cells in the dermis, nor were any positive cells found in the epidermis. Previous studies have shown by radioimmunoassay that large amounts of TRH are present in frog skin, particularly in the dorsal region. Since dorsal frog skin contains many more glands than its ventral counterpart, this non-homogeneous distribution of TRH can be explained by its presence in a population of cells found in one type of cutaneous gland.