Distribution of apelin-synthesizing neurons in the adult rat brain
Section snippets
Animals
Adult male Wistar Kyoto rats weighing 250–300 g were obtained from Iffa Credo (L’Arbresle, France) and kept under artificial light (12 h light/12 h dark cycle) with a normal standard diet (Usine alimentation Rationnelle, Epinay-sur-Orge, France) and water given ad libitum. All of the steps of the experimental procedures were conducted in agreement with the guiding principles for the care and use of experimental animals approved by the Society for Neuroscience.
Chemical synthesis of apelin peptides and production of antiserum against apelin 17
K17F (Lys1
Results
Under the conditions used here for immunohistochemistry, we assumed that the primary antiserum directed to apelin labels specifically neurons that contain the K17F fragment of the preproapelin precursor since we previously reported that the antibody has a high affinity for K17F, no signal was detected in sections after incubation with the preimmune serum or without the primary antibody and that preabsorption of the apelin antiserum with K17F completely blocked the apelin-like immunoreactivity
Discussion
Using a specific polyclonal antiserum directed to the apelin fragment K17F for immunohistochemistry, we established for the first time a detailed distribution of apelinergic neurons in the adult rat brain. The detection of apelin-containing neuronal perikarya and/or fibers was enhanced in this study by several technical improvements including the use of i.c.v. colchicine pretreatment, free-floating sections, DAB revelation and the subsequent light microscopic analysis. The high affinity of the
Acknowledgements
The authors thank J. Helfferich (Laboratory of Neuromorphology, Budapest, Hungary) for skillful technical assistance. This work was supported by grants from the ‘Institut National de la Santé et de la Recherche Médicale (INSERM)’ (APEX No. 4X011E to C.L.-C.) and from a French–Hungarian cooperation (Balaton) managed by the OMFB and CIES (Balaton No. 00831YE to C.L.-C. and M.P.). A.R. received a fellowship from Société Française d’Hypertension Arterielle (2000–2001).
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