<p>Chicken fetuses exposed to chronic hypoxia suffer from growth retardation and</p><p>induces an overall sympathetic activity, including elevation of the concentration</p><p>of circulating catecholamines. Simultaneously, hypoxic fetuses display a</p><p>lowered β-adrenoreceptor (βAR) density in myocardial tissue. In vertebrates,</p><p>β1AR and β2AR are the most important signalling pathways for acute elevation</p><p>of cardiac performance. The aim of this study was to see how chronic hypoxia</p><p>affects the level of messenger RNA (mRNA) for the β1AR in the fetal chicken</p><p>heart at different developmental ages. The broiler chicken is a suitable model</p><p>organism for studying the progression of heart failure because the fast growth</p><p>rate requires a large increase in blood perfusion at the end of fetal development.</p><p>The β1AR sequence of the broiler chicken is 1587 bp and located on</p><p>chromosome 6. When running a PCR for quantification of the sequence,</p><p>primers for almost the whole sequence failed (1404 bp) and so did primers of</p><p>1193 bp; instead primers of 692 bp of the sequence were used and made</p><p>quantification possible. Similar results were obtained from both the heart and</p><p>liver of day 15 fetal chickens. The PCR product was cloned into a TOPO vector</p><p>and sent for sequencing, to enable the making of a probe for a northern blot</p><p>analysis of the mRNA in the fetal chicken hearts.</p>

Chicken fetuses exposed to chronic hypoxia suffer from growth retardation and induces an overall sympathetic activity, including elevation of the concentration of circulating catecholamines. Simultaneously, hypoxic fetuses display a lowered β-adrenoreceptor (βAR) density in myocardial tissue. In vertebrates, β1AR and β2AR are the most important signalling pathways for acute elevation of cardiac performance. The aim of this study was to see how chronic hypoxia affects the level of messenger RNA (mRNA) for the β1AR in the fetal chicken heart at different developmental ages. The broiler chicken is a suitable model organism for studying the progression of heart failure because the fast growth rate requires a large increase in blood perfusion at the end of fetal development. The β1AR sequence of the broiler chicken is 1587 bp and located on chromosome 6. When running a PCR for quantification of the sequence, primers for almost the whole sequence failed (1404 bp) and so did primers of 1193 bp; instead primers of 692 bp of the sequence were used and made quantification possible. Similar results were obtained from both the heart and liver of day 15 fetal chickens. The PCR product was cloned into a TOPO vector and sent for sequencing, to enable the making of a probe for a northern blot analysis of the mRNA in the fetal chicken hearts.