Fig. 14.

(A) Presence of the leptin receptor on the luminal membrane of the rat duodenal wall. Immunohistochemical detection was carried out using an anti leptin receptor antibody followed by a secondary antibody tagged with fluorescein isothiocyanate (FITC). The staining in the form of a thin fluorescent line is present at the apical membrane in contact with the lumen (L) of the duodenum. A much fainter and larger positive signal is also present on the basal side of the epithelial cells. (B) The presence of the leptin receptor at the apical membrane of the duodenal enterocytes has been demonstrated by electron microscopy. Applying the anti-leptin receptor antibody together with the protein A-gold on duodenal tissue sections, led to a labeling by gold particles at the level of the enterocytes apical membrane microvilli (mv) thus confirming the presence of the receptor on the luminal membrane. Scale bars=50 µm (A), 0.5 µm (B).