title: Postnatal changes in inhibitory effect of C-type natriuretic peptide on secretion of ANP.
abstract: To define developmental changes in atrial natriuretic peptide (ANP) secretion and in the cross talk between C-type natriuretic peptide (CNP) and ANP, we performed experiments in isolated perfused nonbeating cardiac atria isolated from rabbits between 1 and 8 wk of age. Changes in atrial pressure resulted in increases in atrial volume that rose with age and reached the peak value at 4 wk. A rise in volume change increased ANP secretion with concomitant translocation of extracellular fluid (ECF) into the atrial lumen, which increased with age and reached the peak value at 4 wk. The positive relationship between stretch-induced ANP secretion and ECF translocation shifted upward and leftward with age. CNP suppressed stretch-induced ANP secretion in the 8-wk-old group but not in the 2- and 4-wk-old groups without differences in ECF translocation and atrial volume. Therefore, the ANP secretion in terms of ECF translocation was markedly suppressed by CNP in the 8-wk-old group but not in the 2- and 4-wk-old groups. The production of cGMP by CNP in atrial tissue membranes was markedly attenuated in young rabbits. However, 8-bromo-cGMP suppressed stretch-induced ANP secretion in 2- and 8-wk-old groups. Natriuretic peptide receptor-B mRNA was similar in both groups. Therefore, we conclude that the inhibitory effect of CNP on atrial ANP secretion is developmentally regulated, being absent during normal cardiac development in young animals and intact in adult animals.
authors: Department of Physiology, Medical School, Institute for Medical Sciences, Jeonbug National University, Jeonju 561-180, Korea. shkim@moak.chonbuk.ac.kr
authors: Suhn Hee
authors: SH
authors: Kim
authors: Jeong Hee
authors: JH
authors: Han
authors: Chunhua
authors: C
authors: Cao
authors: Sung Zoo
authors: SZ
authors: Kim
authors: Kyung Woo
authors: KW
authors: Cho
mesh_terms: D000375:Aging / Q000502:physiology*; D000818:Animals; D009320:Atrial Natriuretic Factor / Q000037:antagonists & inhibitors / Q000378:metabolism*; D001692:Biological Transport / Q000187:drug effects / Q000502:physiology; D006152:Cyclic GMP / Q000031:analogs & derivatives* / Q000096:biosynthesis / Q000494:pharmacology; D005110:Extracellular Space / Q000502:physiology; D006162:Guanylate Cyclase / Q000378:metabolism; D006325:Heart Atria / Q000187:drug effects / Q000378:metabolism; D066298:In Vitro Techniques; D020098:Natriuretic Peptide, C-Type / Q000494:pharmacology / Q000502:physiology*; D009929:Organ Size / Q000502:physiology; D010477:Perfusion; D012333:RNA, Messenger / Q000096:biosynthesis; D011817:Rabbits; D017461:Receptors, Atrial Natriuretic Factor / Q000235:genetics / Q000378:metabolism; D013314:Stress, Mechanical; D000099242:Atrial Natriuretic Factor Receptor B
chemical_list: D009320:Atrial Natriuretic Factor; D006152:Cyclic GMP; D006162:Guanylate Cyclase; D020098:Natriuretic Peptide, C-Type; D012333:RNA, Messenger; D017461:Receptors, Atrial Natriuretic Factor; D000099242:Atrial Natriuretic Factor Receptor B; C016276:8-bromocyclic GMP