Paracrine role of soluble guanylate cyclase and type III nitric oxide synthase in ovine fetal pulmonary circulation: A double labeling immunohistochemical study

Ching Tzao, Peter A. Nickerson, James A. Russell, Bernice K. Noble, Robin H. Steinhorn

Research output: Contribution to journalArticle

7 Citations (Scopus)


Endothelial nitric oxide synthase (eNOS) or NOS-III in the endothelium catalyzes production of nitric oxide (NO). Nitric oxide diffuses freely into vascular smooth muscle, where it activates soluble guanylate cyclase (sGC) to produce guanosine 3′,5′-cyclic monophosphate (cGMP) and causes vasorelaxation. The NO/cGMP pathway is an important signaling pathway in the control of perinatal pulmonary circulation. An exact colocalization of NOS-III in the pulmonary endothelium and sGC in the vascular smooth muscle was demonstrated using a double immunolabeling technique. The sGC immunoreactivity was higher in resistant pulmonary vessels and veins than in conduit arteries, whereas NOS-III immunoreactivity was higher in conduit arteries than in veins. These results demonstrated anatomically in situ a paracrine role of NOS-III and sGC in the regulation of fetal pulmonary circulation and suggested a heterogeneous distribution of NOS-III and sGC within fetal ovine pulmonary vasculature. Our results provided an anatomic basis that supported previous functional studies on perinatal control of pulmonary circulation.

Original languageEnglish
Pages (from-to)125-130
Number of pages6
JournalHistochemistry and Cell Biology
Issue number2
Publication statusPublished - Feb 1 2003
Externally publishedYes



  • Double immunolabeling
  • Fetus
  • Lung
  • NOS
  • sGC

ASJC Scopus subject areas

  • Cell Biology
  • Instrumentation

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