Paracrine role of soluble guanylate cyclase and type III nitric oxide synthase in ovine fetal pulmonary circulation: a double labeling immunohistochemical study.
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.
Tzao
Ching
C
Division of Thoracic Surgery, Tri-Service General Hospital, 325, Section 2, Cheng Gong Road, Nei Hu, Taipei, Taiwan, ROC. tzaoc@ms32.hinet.net
Nickerson
Peter A
PA
Russell
James A
JA
Noble
Bernice K
BK
Steinhorn
Robin H
RH
D000818:Animals; D001158:Arteries / Q000737:chemistry / Q000201:enzymology; D002417:Cattle; D004730:Endothelium, Vascular / Q000737:chemistry / Q000201:enzymology; D005260:Female; D006162:Guanylate Cyclase / Q000032:analysis / Q000378:metabolism*; D006801:Humans; D015151:Immunoblotting; D007150:Immunohistochemistry; D008168:Lung / Q000098:blood supply* / Q000196:embryology; D009131:Muscle, Smooth, Vascular / Q000737:chemistry / Q000201:enzymology; D019001:Nitric Oxide Synthase / Q000032:analysis / Q000378:metabolism*; D052250:Nitric Oxide Synthase Type III; D038081:Organogenesis; D019899:Paracrine Communication / Q000502:physiology*; D012756:Sheep / Q000502:physiology*
C496314:NOS3 protein, human; D019001:Nitric Oxide Synthase; D052250:Nitric Oxide Synthase Type III; D006162:Guanylate Cyclase