Travel grants to go - Edward (Ned) Snelling

31 May 2019 - By: Edward Snelling

Travel grants to go - Edward (Ned) Snelling

Edward Snelling and Dr Tilaye Wube
Edward Snelling and Dr Tilaye Wube. Photo: Anteneh Tesfaye

Ned travelled on a research trip to Dr Tilaye Wube’s lab at Addis Ababa University in Ethiopia to carry out collaborative research entitled “Scaling of the morphology of the developing heart”.

“The functional performance of the heart increases greatly across fetal and postnatal development, both in terms of absolute output and generated pressure. The morphology of the heart therefore must also change across development, but it is difficult to tease apart changes in cardiac morphology that are related to body mass and changes that occur independently of body mass. Our approach was to use a scaling analysis (allometry) to describe the change in heart mass, left and right ventricular masses, and ventricular mass ratio, each as a function of body mass, across fetal and postnatal development in sheep” explains Ned.

“Previous work on the scaling of heart size across development in marsupial kangaroos revealed a biphasic relationship between heart mass and body mass, with heart mass increasing faster than body mass (positive allometry) across in-pouch life, before a switch in the pace of cardiac growth at pouch exit, with heart mass increasing slower than body mass (negative allometry) across post-pouch life. We expected to find a similar biphasic scaling pattern of cardiac growth in our placental sheep. Instead, the breakpoint that we observed was due to a rapid and substantial increase in the mass of the heart at birth, which occurred independent of any increase in body mass. When we examined the dataclosely, we saw that the left ventricular mass more than doubles within the first few days of postnatal life, which we think is a response to an increase in left ventricular wall stress at birth, brought about primarily by an increase in volume loading, and secondarily by an increase in pressure loading at birth.

The collaboration with Dr Wube – one of only a few animal eco-physiologists in east Africa – was a great highlight of the research trip. It provided an academic connection between South Africa and Ethiopia which will certainly continue through more collaborative research projects between our laboratories. Of course, another major highlight was the Ethiopian cuisine, which included beef tibs, injera and the famous St George beer!”

The work will be published in the July 2019 issue of the Journal of Anatomy.

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