How studying shrews and bats can help us develop treatments for diastolic heart disease
“The story just seemed too perfect. It was just too ideal to go from the smallest mammals with the highest heart rates on the planet, to potential therapeutic applications to humans”, says Dr. Kevin Campbell, professor at the department of biological sciences at the University of Manitoba. Campbell has done research on the comparative physiology and evolution of mammals ranging from the smallest shrews to the largest whales over the past two decades and has published his recent findings in the multidisciplinary journal Science.
In this study, cardiac troponin is the star of the show, a protein that is highly conserved in all terrestrial vertebrates. It’s what keeps the heart beating continuously through binding and releasing calcium ions. Troponin makes sure that when our heart contracts faster, it also relaxes faster, allowing the heart more time to fill between beats. It’s interesting to know the smaller the animal, the higher their need for oxygen and therefore the faster their heart beats. But how does this look for the extremely small animals? How do the tiniest of mammals like shrews maintain a heart rate of over 1,000 beats per minute at rest?
“For shrews, as they got really tiny, smaller and smaller, their heart rates had to continually go higher”, Campbell tells us, “And at some point, there was really not enough time for them, even at rest, for their hearts to fill properly”. With Campbell’s expertise, he started looking into genomes of high heart rate shrews, bats, and moles, noticing differences in how their troponin protein evolved to solve this problem. Campbell tells us that this recent finding can have the potential to be applied to humans for the treatment of diastolic heart disease.
To learn more about Campbell’s research and his work, please visit the video on the Faculty of Science’s YouTube channel.