title: Angiotensin II binding sites in the rat pancreas and their modulation after sodium loading and depletion.
abstract: Specific 125I angiotensin II binding sites were identified in the rat pancreas by radioreceptor assay, autoradiography and immunohistochemistry. Scatchard analysis of the binding in normal rats yielded a Kd of 0.51 +/- 0.23 nM with a Bmax of 15 +/- 3.5 fmol/mg protein (means +/- SD, n = 6). Changed plasma sodium concentration resulted in modifications in the binding affinity and capacity. Sodium loading depressed both Kd (0.36 +/- 0.1 nM) and Bmax (6.4 +/- 0.1 fmol/mg protein), while sodium depletion elevated both Kd (2.03 +/- 0.3 nM) and Bmax (45 +/- 3.5 fmol/mg protein) (means +/- SD, n = 6). Autoradiography using 125I Ang II and immunohistochemistry of the binding sites saturated with unlabeled Ang II and incubated with Ab-Ile5 Ang II, revealed localization of the binding sites on the islet cell membranes and in the exocrine pancreas.
authors.affiliation: Istituto di Anatomia Comparata, Università di Genova, Italy.
authors.forename: B U
authors.initials: BU
authors.lastname: Ghiani
authors.forename: M A
authors.initials: MA
authors.lastname: Masini
mesh_terms: D000804:Angiotensin II / Q000378:metabolism*; D000818:Animals; D001345:Autoradiography; D004232:Diuretics / Q000494:pharmacology; D004326:Drinking; D004573:Electrolytes / Q000097:blood / Q000652:urine; D007150:Immunohistochemistry; D007457:Iodine Radioisotopes; D008297:Male; D009994:Osmolar Concentration; D010179:Pancreas / Q000187:drug effects / Q000378:metabolism*; D011869:Radioligand Assay; D051381:Rats; D017207:Rats, Sprague-Dawley; D011945:Receptors, Angiotensin / Q000187:drug effects / Q000378:metabolism*; D012083:Renin / Q000097:blood; D012964:Sodium / Q000494:pharmacology / Q000502:physiology*
chemical_list: D004232:Diuretics; D004573:Electrolytes; D007457:Iodine Radioisotopes; D011945:Receptors, Angiotensin; D000804:Angiotensin II; D012964:Sodium; D012083:Renin