Life Lines by Dr. Dolittle

Sponsored by the American Physiological Society

Diet and Exercise

Hypoxia improves exercise duration

Speaking of hypoxia, a new study published in Physiological Reports examined how training for 2 weeks under 18% hypoxia impacts muscles of Thoroughbred horses. Unlike humans, these horses do not increase production of red blood cells to enhance oxygen transport throughout the body under hypoxic conditions. This difference led researchers to speculate that the horses had other ways of adapting to exercise.   In the new study, horses were trained […]

Continue Reading →

Physiology of diving animals: how do they deal with hypoxia?

Dr. Jose Pablo Vazquez-Medina (pictured at right), a comparative physiologist at the University of California – Berkeley, was scheduled to present several ongoing studies from his lab at the Experimental Biology conference last month. Dr. Vazquez-Medina is a member of the Comparative and Evolutionary Physiology section of the American Physiological Society. Although the conference was cancelled due to Covid-19, Dr. Vazquez-Medina has agreed to share his research with us.   […]

Continue Reading →

Seagulls pick up on human cues to find food

Have you ever experienced seagulls seemingly begging for food from you? It is not your imagination. A new study finds that seagulls really do prefer foods that have been handled by humans. The study conducted Madeleine Goumas (University of Exeter, UK) examined whether seagulls picked up on cues from humans or were simply looking for food. While standing about 8 meters away from herring gulls, the team placed two plastic-wrapped […]

Continue Reading →

Developing Pacific molluscs produce their own carbohydrates

Animals that develop within an egg, must rely on the egg yolk for nutrition for healthy development. While we have known that proteins and fats in the egg are important for development, the role of carbohydrates in the development of molluscs is a bit vague. A new study published in the American Journal of Physiology – Regulatory, Integrative and Comparative Physiology examined the role of carbohydrates in the development of Pacific […]

Continue Reading →

Why pigs and people absorb more sugar from their diet than fish

Researchers at the University of Saskatchewan in Canada compared how pigs and fish absorb glucose (i.e. sugar) from the diet. They did this by measuring how well glucose moves across the intestinal wall. Their findings appear in the American Journal of Physiology – Regulatory, Integrative and Comparative Physiology.  Transport of dietary glucose from the gut to the blood is facilitated by glucose transporters that pick up glucose and move it […]

Continue Reading →

First ever recording of heart rate in free swimming blue whales

While we are on the topic of whales, I found additional research published in the Proceedings of the National Academy of Sciences USA on these animals and how their hearts function that I find fascinating. Talk about extreme physiology! Researchers from Stanford University were able to attach surface electrodes to blue whales using suction cups. This allowed them to measure – for the first time – how heart rate changes during […]

Continue Reading →

Researchers explore how the largest animals get enough to eat

Ever wonder how baleen whales (Mysticeta) get enough to eat? The mechanism is described for rorqual whales (Balaenopteridae) in a review article published this past October in Physiology. Researchers have found that rorqual whales (ex: blue whales and fin whales), in particular, have an interesting strategy for foraging. The process includes 5 steps that take place in rapid succession (about 20-90 sec total): quick forward lunges toward prey; opening their […]

Continue Reading →

Low-calorie sweeteners – harmful or hype?

Researchers at Columbia University wanted to examine whether low-calorie sweeteners disrupt glucose tolerance as there are conflicting reports in both human and animal studies. Their results examining the link between low-calorie sweeteners and glucose regulation in mice are published in the upcoming issue of the American Journal of Physiology – Regulatory, Integrative and Comparative Physiology. In their first experiment, the research team found no differences in glucose tolerance or body […]

Continue Reading →

Importance of feeding chicks shortly after hatching

While egg yolks are rich in lipids, chicks consume mainly carbohydrates after hatching. This ability to switch between using nutrients provided by the mother in the egg and those the chick must acquire from the environment is important for the normal growth and metabolism of the birds after hatching. Delayed access to foods after hatching can therefore have long term effects on the animals. Transport of animals from hatcheries to […]

Continue Reading →

Researchers explore why fetuses that experienced intrauterine growth restriction have smaller muscles

We have talked several times about the long-lasting issues related to growth restriction of a fetus during pregnancy: Intrauterine growth restriction increases risk of cardiovascular disease as adults Intrauterine growth restriction increases risk of insulin resistance as adults It can also result in offspring that have smaller muscles. New research published in the American Journal of Physiology – Regulatory, Integrative and Comparative Physiology suggests this may be due to adaptations to […]

Continue Reading →