Life Lines by Dr. Dolittle

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Tag Archive for ‘American Physiological Society’

Causes and consequences of stiff arteries

In a new review article published in Physiology, researchers speculate that arterial stiffness in middle-aged adults may actually be the body’s way of trying to compensate for widening of the blood vessel walls as we age. But that benefit turns into a risk with aging as it increases the flow of blood into organs like the brain, kidney, and heart and damages the small blood vessels in those organs. Interestingly, […]

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Heat may activate muscle growth and prevent atrophy

Skeletal muscle is not only important for our ability to move, it also plays a major role in metabolism. Under normal conditions, the routine processes of muscle growth (hypertrophy) and breakdown (atrophy) are in balance. While many of us are aware that exercise and healthy diets promote muscle growth, diseases and sedentary lifestyles can promote muscle atrophy. Studies examining the effects of heat on muscle – from environmental heat, direct […]

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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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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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Geriatric bees

Jacob Pithan, a graduate student in the laboratory of Dr. Kendra Greenlee (North Dakota State University), presented their research examining how aging affects exercise performance as well as oxidative health at last month’s Experimental Biology conference in Philadelphia. The oxidative stress theory of aging postulates that aging results from an overproduction of free radicals along with a decrease in antioxidants that can scavenge them. The problem with free radicals is […]

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Grappling with gravidity

In humans, pregnancy can be an uncomfortable time as the growing fetus makes it more difficult to breathe. It can also become more difficult for the expectant mother to get around. It may be surprising to find out that grasshoppers may develop similar issues when they are ‘expecting’. In fact, a gravid grasshopper can carry an egg mass that makes up as much as 40% of their weight! Could you […]

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EB 2022: Seals, seals, and more seals

Several posters at EB 2022 in Philadelphia this month were focused on understanding the remarkable physiology of diving seals. Although we may think of the image below when we picture seals, they really are quite the athletes in water. Kaitlin Allen (a graduate student working in the laboratory of Dr. José Pablo Vázquez-Medina at the University of California Berkeley) presented her research on Northern elephant seals and how these animals […]

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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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