Does the olfactory system mediate water- and mineral-regulating mechanisms? Evidence of immunoreactive atrial natriuretic factor within olfactory mucosa.
The immunoreactivity of atrial natriuretic factor (ANF) was studied in the rat olfactory mucosa (OM). Endogenous immunoreactive ANF (IR-ANF) was purified from OM using Vycor glass beads for extraction and reverse-phase HPLC: two of three IR-ANF peaks, identified by retention time, were identical to both the circulating form of ANF (Ser99-Tyr126) and the ANF pro-hormone (Asn1-Tyr126). A radioreceptor assay, employing rat renal glomerular membranes, revealed that endogenous IR-ANF competed with radiolabelled ANF. IR-ANF was localized by immunocytochemistry in secretory cells of Bowman's gland and in some cells of the epithelial layer. The relatively low concentration of IR-ANF in the OM (2.5 ng/mg protein) suggests a local role of ANF in this tissue. This hypothesis is supported by the presence in OM of ANF-binding sites, characterized by a KD of 95 pM and a Bmax of 130 fmol/mg protein. We propose that ANF could be released from the OM and act throughout in a paracrine (if not autocrine) manner on some yet-unidentified targets containing ANF-binding sites.
Gutkowska
J
J
Laboratory of Biochemistry of Hypertension, Clinical Research Institute of Montreal, Quebec, Canada.
Marcinkiewicz
M
M
D000818:Animals; D009320:Atrial Natriuretic Factor / Q000032:analysis* / Q000276:immunology / Q000302:isolation & purification; D002851:Chromatography, High Pressure Liquid; D005260:Female; D007124:Immunoenzyme Techniques; D007150:Immunohistochemistry; D009831:Olfactory Mucosa / Q000032:analysis / Q000166:cytology / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D017461:Receptors, Atrial Natriuretic Factor; D011956:Receptors, Cell Surface / Q000378:metabolism; D014882:Water-Electrolyte Balance
D011956:Receptors, Cell Surface; D009320:Atrial Natriuretic Factor; D017461:Receptors, Atrial Natriuretic Factor