ABSTRACT
Peptides corresponding to sequences derived from predicted extra- and intracellular loops of the rat bradykinin receptor were analyzed for interspecies homology as well as for matches within the present dataset of protein sequences to provide a theoretical basis for the specific recognition of the native cognate protein by antibodies raised against these antigens. Apllication of polyclonal antibodies raised against the selected peptides allowed the immunocytochemical localization of the native receptor protein in cells of rat and human origin. The detection of the molecule was achieved by different immunohisto- and immunocytochemical methods in combination with light, fluorescence, confocal optical laser and electron microscopy. These results were compared to localization studies by autoradiography. Distribution and subcellular localization were determined in human neutrophils, human epithelial carcinoma cells (A431) and in rat kidney tissue
Subject(s)
Rats , Humans , Animals , Kinins/physiology , Neutrophils/metabolism , Receptors, Bradykinin/metabolism , Amino Acid Sequence , Autoradiography , Binding Sites, Antibody , Cells, Cultured , Culture Techniques , Species Specificity , Fluorescent Antibody Technique , Immunoenzyme Techniques , Kidney/metabolism , Sequence Homology , Tumor Cells, CulturedABSTRACT
In the kidney, renal atrial natriuretic peptide (ANP) is considered to play an important role wter and salt homeostasis. Immunoreactive ANP in the brain of lower invertebrates, such as the rat, has been shown to be localizaed in the hypothalamus and septum. Several studies have investigated the possibility of a regulatory system in the brain similar to that of the kidney. Since neuronal function is acutely sensitive to disturbances of the intracranial water and salt balance we have attempted to immunolocalize ANP-containing cells in the normal human hypothalamus, using a polyclonal antiserum specific to ANP. Also, we have observed tissue kallikrein (TK), using a polylonal antiserum specific to TK, in the same areas as ANP. A regulatory role for TK on prolactin has been suggested as the rationale for the co-localization of these two hormones in human prolactinomas. Therefore, it could be suggested that TK plays a similar role in the processing of precursor ANP in the brain. It is contemplated to examine the status of these peptides in patients with cerebral oeodema