Life Lines by Dr. Dolittle

Sponsored by the American Physiological Society

Comparative Physiology

Infertility is not an issue for naked mole rats

Naked mole-rats have attracted the attention of scientists once again. Not only do they live very long lives (30+ years), while typically avoiding cancer, females remain fertile their whole life. Unlocking their secrets to avoiding menopause may lead to new ways to treat infertility. New research has identified their tricks for lifelong fertility. It turns out that female naked mole-rats have 1.5 million egg cells (oocytes) when they are born, […]

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The biological importance of carbonic anhydrase enzyme

Carbonic anhydrase is an important enzyme that regulates the acid-base balance of an organism. In fact, carbonic anhydrase (CA) is so important to homeostasis, it is found in all living organisms studied to date – from microorganisms (like bacteria) to mammals. As the name implies, this enzyme is responsible for catalyzing the hydration of carbon dioxide, which is a reversible process (see figure above). In other words, it speeds up […]

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On the road to developing artificial odorant sensors for noses

Almost all animals have some ability to detect smells their environment and there are countless odorant molecules and combinations of molecules in the environment that our systems are challenged with identifying. The sense of smell is important in many biological processes such as finding food, mates, and detecting threats. Scents may also conjure up memories and affect our emotions. About 5% of the population either has no (anosmia) or very […]

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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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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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Under pressure: One way our bodies regulate blood pressure

Did you know that blood vessels come fully equipped with the ability to help regulate blood pressure? This is possible because of smooth muscle cells that wrap around blood vessels (see image above). Because they wrap around the inner layers of the blood vessel, when these cells contract, the lumen od the blood vessel becomes narrow and increases blood pressure. When they relax, the blood vessels widen thereby lowering blood […]

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Humans do it, cats do it, dogs do it…why can’t rodents or rabbits do it?

Did you know that rodents and rabbits are not able to vomit? This was certainly news to me. So, I had to find out more… First, let’s talk about the difference between retching and vomiting. During retching (or dry heaves), the diaphragm and abdominal muscles contract, which helps increase pressure within the stomach (and prepare the contents for expulsion). Vomiting also involves contractions of the diaphragm, abdominal as well as […]

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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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EB 2022: Modeling human diseases and healthy aging

I sat through a very interesting session at this year’s Experimental Biology conference called, “The Power of Comparative Models for Accelerating Translational Healthspan Research: Underutilized Lab Animals, Companion Pets, Old World Monkeys, and Pumas.” While the title seems to capture the general idea of the symposium, I thought I would share a bit more information about the presenters and their exciting research. Dr. Karyn Hamilton from Colorado State University presented […]

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