| First Author | Reiss K | Year | 1996 |
| Journal | Proc Natl Acad Sci U S A | Volume | 93 |
| Issue | 16 | Pages | 8630-5 |
| PubMed ID | 8710922 | Mgi Jnum | J:35215 |
| Mgi Id | MGI:82668 | Doi | 10.1073/pnas.93.16.8630 |
| Citation | Reiss K, et al. (1996) Overexpression of insulin-like growth factor-1 in the heart is coupled with myocyte proliferation in transgenic mice. Proc Natl Acad Sci U S A 93(16):8630-5 |
| abstractText | Transgenic mice were generated in which the cDNA for the human insulin-like growth factor 1B (IGF-1B) was placed under the control of a rat alpha-myosin heavy chain promoter. In mice heterozygous for the transgene, IGF-1B mRNA was not detectable in the fetal heart at the end of gestation, was present in modest levels at 1 day after birth, and increased progressively with postnatal maturation, reaching a peak at 75 days. Myocytes isolated from transgenic mice secreted 1.15 +/- 0.25 ng of IGF-1 per 10(6) cells per 24 hr versus 0.27 +/- 0.10 ng in myocytes from homozygous wild-type littermates. The plasma level of IGF-1 increased 84% in transgenic mice. Heart weight was comparable in wild-type littermates and transgenic mice up to 45 days of age, but a 42%, 45%, 62%, and 51% increase was found at 75, 135, 210, and 300 days, respectively, after birth. At 45, 75, and 210 days, the number of myocytes in the heart was 21%, 31%, and 55% higher, respectively, in transgenic animals. In contrast, myocyte cell volume was comparable in transgenic and control mice at all ages. In conclusion, overexpression of IGF-1 in myocytes leads to cardiomegaly mediated by an increased number of cells in the heart. |
