ULTRACYTOCHEMICAL LOCALIZATION OF PARTICULATE GUANYLATE-CYCLASE IN RAT ADRENAL-GLAND EXPOSED TO STIMULATION BY PORCINE BRAIN NATRIURETIC PEPTIDE

We studied the cytochemical localization of particulate guanylate cycl ase (GC) in rat adrenal gland after stimulation with porcine brain nat riuretic peptide (pBNP) by electron microscopy. In the adrenal cortex, GC activity, as demonstrated by the presence of reaction product, was prevalently localized to the zona glomerulosa and zona fasciculata, w hile the zona reticularis showed little GC reaction product. In the ad renal medulla, GC reaction product was present only in adrenalin-conta ining cells. All GC positivity was associated with intracellular membr anes. No GC reaction product was detected in specimens incubated in me dia devoid of pBNP. In parallel samples incubated in the presence of r at atrial natriuretic factor (rANF), the distribution of rANF-stimulat ed GC activity was similar to that of pBNP-stimulated GC activity.