Life Lines by Dr. Dolittle

Sponsored by the American Physiological Society

Environment

Hypoxia gives alligators a big heart: Q&A with Dr. Dane Crossley, University of North Texas

We recently interviewed Dr. Dane Crossley, Professor of Physiology in the College of Biological Sciences at the University of North Texas about the research his laboratory presented at the recent APS Intersociety meeting, Comparative Physiology: From Organisms to Omics in an Uncertain World. The title of his presentation was, “A large heart: How does developmental hypoxia affect individual cardiomyocyte performance in the American alligator, Alligator mississippiensis.” Thank you for taking time […]

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Arizona physiologists gathered recently for their annual meeting

The Arizona Physiological Society, a chapter of the American Physiological Society, hosted their 15th annual scientific meeting this past weekend! Here are some highlights… The Keynote Address was presented by Dr. Harold D Schultz, Professor in the Department of Cellular and Integrative Physiology at the University of Nebraska. His talk focused on the physiology of heart failure and how the nervous system regulates blood pressure. This year’s Arizona Distinguished Physiologist […]

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Making heat to lose weight

There are many ways to stay warm on a cold day. We can seek shelter, turn up the thermostat, and huddle close together. Obvious physical adaptations to cold include fur, feathers, and clothing in the case of humans…and some pampered dogs. Blood vessels near the skin may also constrict to prevent heat loss and some animals develop a layer fat under the skin that acts like insulation. We may also […]

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Life at the top

Moving to high altitude requires a bit of an adjustment. One of the ways our bodies adjust to the low levels of oxygen is by making more red blood cells, which are responsible for transporting oxygen in the body. More red blood cells means that our blood can pick up more oxygen. If this process continues unchecked, however, it can lead to chronic mountain sickness, also known as Monge’s Disease. […]

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Domestic zebrafish are less plastic

Zebrafish have been used in medical research since at least the 1970’s as their anatomy, physiology, as well as genetics are similar to humans. Other advantages to studying zebrafish is that they are inexpensive to raise, and they reproduce well in captivity. The ability to adjust one’s physiology in response to varying environments is called plasticity. An organism may encounter any number of environmental fluctuations (light/dark, temperatures, predation risk, noise, […]

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Are declines in food availability to blame for the menu change?

Yesterday, we marveled over the recent sightings of two killer whales targeting sharks off the coast of South Africa. The recent uptick in shark hunting has scientists wondering how the loss of great white sharks will impact the ecosystem. But it also has some wondering why the orcas are targeting so many sharks when their diets typically consist of a variety of fish and marine mammals.   Clues may lie […]

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Killer whales scare off sharks

A pair of killer whales, nicknamed ‘Port and Starboard’, has been terrorizing great white sharks. In recent years as many as 8 sharks (possibly more) have succumbed to the pair. Many of the discovered sharks were missing their fatty liver and sometimes their heart. While orca hunting escapades are not particularly newsworthy, the antics of these orcas have attracted the attention of scientists as they are altering the ecosystem. Once […]

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Turning up the heat

There are several ways to stay warm on a cold day. If you are human, you can turn up the heat in your home, put on a sweater, snuggle, and even produce body heat through shivering as well as non-shivering metabolic pathways – although the ability to produce heat metabolically typically declines with aging. If you are a small mammal, turning up the heat or putting on a sweater are […]

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Nitrites and noses

If you have ever had a fish tank, you may be familiar with monitoring ammonia levels in the water. Ammonia levels can rise due to overcrowding, overfeeding, as well as fish waste. Nitrite levels in the water also require monitoring as nitrite can bind to hemoglobin, which prevents oxygen from binding. In effect, by preventing oxygen from binding, the fish can succumb to hypoxia. Hannah Hughes, a graduate student working […]

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More than milk

Prolactin is an important pituitary hormone in mammals that works with oxytocin to provide milk for offspring. It also plays a role in promoting bonding between new mothers and their offspring. But did you know that non-mammalian vertebrates have prolactin too? Considering non-mammalian organisms do not have mammary glands, it must serve a different purpose in these animals.   As it turns out, prolactin is very important in the ability […]

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