Transcription levels of endothelin-1 and endothelin receptors are associated with age and leaflet location in porcine mitral valves.
The aim of the study was to investigate the expression levels of endothelin-1 (ET-1) and ET(A) and ET(B) receptors (ET(A)-R and ET(B)-R) in porcine mitral valves and associate the transcription levels to age, leaflet location and deposition of mucopolysaccharides (MPS). Tissue samples from the chordal and inter-chordal insertion area of the anterior mitral valve leaflet from 11 sows (> or = 2 years of age) and 10 slaughter pigs (approximately 6 months old) were obtained and the relative gene expression levels of ET-1, ET(A)-R and ET(B)-R measured by semi-quantitative real-time PCR. A separate tissue sample was taken for histopathological grading of MPS deposition. The transcription levels of ET-1 (P < 0.0001) and ET(A)-R (P < 0.0004) were significantly higher in leaflets from the sows compared with slaughter pigs. The gene expression of ET(B)-R was not associated to age (P = 0.38), but increased in chordal insertion areas compared with inter-chordal areas (P = 0.01). The expression of ET-1 and ET(A)-R mRNA did not differ significantly between the two leaflet locations. The valve leaflets from sows had a significantly increased degree of MPS deposition compared with slaughter pigs upon histological examination (P = 0.04). In conclusion, an age-related valvular degeneration is observed in porcine mitral valve leaflets and ET-1 is suggested to be involved through action of both ET(A) and ET(B) receptors.
Pedersen
L G
LG
Department of Basic Animal and Veterinary Sciences, The Royal Vetinary and Agricultural University, Copenhagen, Denmark.
Offenberg
H
H
Moesgaard
S G
SG
Thomsen
P D
PD
Pedersen
H D
HD
Olsen
L H
LH
D000367:Age Factors; D000818:Animals; D019332:Endothelin-1 / Q000235:genetics / Q000378:metabolism*; D005260:Female; D008297:Male; D008943:Mitral Valve / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D044022:Receptor, Endothelin A / Q000235:genetics / Q000378:metabolism*; D044023:Receptor, Endothelin B / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods / Q000662:veterinary; D013552:Swine
D019332:Endothelin-1; D012333:RNA, Messenger; D044022:Receptor, Endothelin A; D044023:Receptor, Endothelin B