Insulin-like growth factor-I gene expression is increased in the right ventricular hypertrophy induced by chronic hypoxia in the rat.
Rats were maintained in chambers and breathed air (control, n = 8) or an atmosphere containing 10% oxygen (hypoxic, n = 10) for 35 days. On completion of the experiment the hypoxic animals weighed less than the controls (hypoxic, 290 +/- 11.7g; control, 339 +/- 19.2g; means +/- S.E.M., p < 0.05). No differences in the left ventricular weights were found between groups but the right ventricular weights were greater in the hypoxic rats (hypoxic, 0.39 +/- 0.02g; control, 0.27 +/- 0.08g; p < 0.01). The amount of mRNA for IGF-I in the ventricles was quantified by Northern blot analysis. There was no difference between groups in IGF-I mRNA levels in the left ventricles (hypoxic, 1.07 +/- 0.41 absorbance units (AU); control, 0.73 +/- 0.33 AU). In the right ventricles, IGF-I mRNA was greater in hypoxic than in control rats (hypoxic, 2.37 +/- 0.75 AU; control, 0.64 +/- 0.11 AU; p < 0.05). This study demonstrates that expression of IGF-I mRNA is increased in the hypertrophied right ventricle of hypoxic rats; IGF-I may play a central role in the initiation and maintenance of this process.
Russell-Jones
D L
DL
Department of Endocrinology & Chemical Pathology, UMDS, St Thomas' Hospital, London, UK.
Leach
R M
RM
Ward
J P
JP
Thomas
C R
CR
D000818:Animals; D002908:Chronic Disease; D015870:Gene Expression; D006352:Heart Ventricles / Q000378:metabolism; D017380:Hypertrophy, Right Ventricular / Q000209:etiology / Q000235:genetics* / Q000378:metabolism; D000860:Hypoxia / Q000150:complications / Q000235:genetics* / Q000378:metabolism; D007334:Insulin-Like Growth Factor I / Q000235:genetics*; D008297:Male; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar
D012333:RNA, Messenger; D007334:Insulin-Like Growth Factor I