Life Lines by Dr. Dolittle

Hibernation and Hypoxia

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Can carbon monoxide be a good thing at high altitude?

Although carbon monoxide inhalation is dangerous because it can cause blood poisoning, research suggests that production of carbon monoxide in the body may actually protect cells during exposure to hypoxic environments as well as during ischemic-reperfusion injuries. Carbon monoxide is produced in the body by the enzyme heme oxygenase. This enzyme is responsible for converting heme into biliverdin and generates carbon monoxide in the process. Interestingly, carbon monoxide levels are […]

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Understanding hypoxia tolerance

Hypoxia associated with ischemic stroke, heart attacks, and solid tumors causes significant pathologies in humans. However, some populations of humans that have lived at high altitudes for generations have adaptations that provide some measures of hypoxia tolerance that may lend insight into treatments for pathological hypoxia in disease states.    Researchers seeking to understand hypoxia tolerance compared the genome of Andean and Ethiopian highlander populations with the genome of Drosophila […]

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Sleep prolongs lifespan

If only all mammals could hibernate. Studies have shown that some species of hibernating animals live longer and age more slowly than animals that do not hibernate. In fact, a recent study has shown that hibernation slows biological aging in yellow-bellied marmots. During hibernation, an animal’s metabolism slows to conserve energy. In the case of the yellow-bellied marmots, metabolism drops to only 1% of non-hibernating levels. The researchers observed that […]

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Now we know how life underground reduces metabolism

…at least for mole-rats. African mole-rats live in dark underground dwellings where oxygen and food are scarce, and humidity and temperatures are high. These animals have low metabolic rates and body temperatures uniquely adapted to their life underground. Metabolism is controlled in part by thyroid hormones. To understand the role of thyroid hormone in mole-rats, researchers examined the thyroid gland and hormones in naked mole-rats (Heterocephalus glaber) as well as […]

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Hummingbirds can choose how deep to sleep

Could you imagine drinking a can of soda every minute just to support your high metabolism? Amazingly, that is the equivalent to how much sugar a hummingbird needs to support their rapid wingbeats during flight. In fact, hummingbird flight muscles are the fastest on record, allowing the birds to flap their wings at a rate of up to 200 beats per second! That explains why they are always at my […]

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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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It’s getting cold outside…what’s a squirrel to do?

As the weather cools down, animals must find ways to stay warm. This is especially important for small animals as they lose body heat faster than larger animals. One way to stay warm is by increasing your metabolism to create body heat, although this process requires a lot of energy. That can be a problem in areas where food may be scarce in the winter. Although some animals, like the […]

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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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Chronic stress during pregnancy increases risk of stillbirth and preterm delivery

At the end of pregnancy, levels of the hormone oxytocin increase to stimulate parturition, or childbirth. The stress hormone cortisol is also important for normal fetal development and, like oxytocin, cortisol increases at the end of pregnancy. This may help explain why chronic stress during pregnancy increases the risk of complications such as stillbirth.   A new study published in the American Journal of Physiology – Regulatory, Integrative and Comparative […]

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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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