Life Lines by Dr. Dolittle

Tag Archive for ‘hypoxia’

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Lactate directly increases breathing

Hypoxic environments increase ventilation in animals. This helps to bring in more oxygen when environmental levels may be limited. With limited oxygen availability, the body turns to anaerobic metabolism, resulting in the production of lactate ions. These ions are known to indirectly stimulate breathing by lowering blood pH and were more recently discovered to directly stimulate the carotid body to increase breathing. For this reason, lactate ions are thought to […]

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Hypoxia and anoxia and reoxygenation, Oh my!

There are many examples of animals that can naturally tolerate hypoxic and anoxic conditions without exhibiting pathologies associated with reoxygenation. Here are a few examples from this year’s conference: Dr. Anthony Signore (University of Nebraska) spoke about how some hypoxia tolerant animals can use carbon monoxide, you know that gas we think of as poisonous, to improve oxygen binding to hemoglobin in hypoxic conditions. Well known for their ability to […]

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How Animals Deal with Stress

  Victor Zhang (Graduate Student working with Dr. Loren Buck at Northern Arizona University) gave an interesting talk on his research to measure stress and activity patterns in free living arctic ground squirrels. They found overall that females were less stressed than males although stress levels and activity varied during lactation. I think some human mothers can agree with those observations. Oliver Wearing (Graduate student working with Dr. Graham Scott […]

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Study examines link between sleep apnea and cancer

A recent review published in the American Journal of Physiology – Regulatory, Integrative and Comparative Physiology explored the link between sleep apnea and cancer (4). More and more people are living with sleep apnea. In fact, current estimates indicate that up to 24% of men as well as up to 5% of women have obstructive sleep apnea (4). Individuals with sleep apnea experience repeated cycles of low oxygen (hypoxia) and reoxygenation throughout […]

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Chocolate: Bad for Fido, good for us?

Many animals, especially dogs and cats, cannot tolerate theobromine which is an alkaloid from the cacao plant. Studies of humans, however, have found many beneficial health effects of theobromine, caffeine as well as flavonoids found in cocoa (Martinez-Pinilla et al., 2015). A new study published in Journal of Applied Physiology examined whether cocoa extract can improve heart health in individuals exercising in hypoxic conditions. Hypoxia (i.e. low atmospheric oxygen) reduces the […]

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Seals have anti-inflammatory blood

Dr. Allyson Hindle from Massachusetts General Hospital in Boston, presented some interesting research on seals at the Experimental Biology conference this week in San Diego. Seals are known for being rather plump, which for humans often leads to inflammation and cardiovascular disease. In addition, seals undergo repeated bouts of hypoxia and reoxygenation during their dives, which is also known to promote inflammation and cardiovascular disease in humans. Her research team […]

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Experimental Biology 2017 – Day 5

Here are the highlights from the final day of the meeting: Carbon monoxide (CO) is not all that bad: Michael Tift, graduate student at Scripps Institute of Oceanography, described how the body naturally produces CO when red blood cells are broken down and CO can actually be protective against inflammation at low doses. His research was focused on measuring whether species that have more hemoglobin (from living in hypoxic environments) also have […]

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Experimental Biology – Day 4

The August Krogh Distinguished lecture was awarded to Dr. Warren Burggren, who gave a fantastic lecture on epigenetics, or modifications to gene expression. He discussed how epigenetic changes to our genes are reversible. So when a stimulus like hypoxia changes our genes, these epigenetic changes to the genes go away rather quickly when the hypoxic insult is gone, which contrasts genetic mutations that arise from modifications to the genetic code leading […]

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Experimental Biology – Day 2

Yesterday was a great day for comparative physiology! Highlights from the seminars on comparative physiology: Melissa Reiterer, graduate student from Florida Atlantic University, presented her research on how freshwater turtles (Trachemys scripta) survive for long periods of time without oxygen and do not develop oxidative stress after oxygen is restored. The turtles are able to do this by creating their own antioxidants as well as eliminating oxidative stress. In contrast, mammals including humans, develop […]

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How to grow a bigger heart…

…in alligators at least. Researchers from the University of Manchester, University of North Texas – Denton, and the Rockefeller Wildlife Refuge – Grand Chenier, Louisiana teamed up to explore the effects of exposure to low oxygen on embryonic American alligators (Alligator mississippiensis). Alligator eggs are often laid in nests where oxygen concentrations can reportedly vary between 11-20% (21% is normal atmospheric levels). This is really important as issues related to embryonic development could continue to affect animals throughout their adult lives […]

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