Ed Dzialowski | Department of Biological Sciences

Ed Dzialowski

Ed DzialowskiAs an undergraduate, Dr. Ed Dzialowski began studying bird eggs. Now as an Associate Professor of Biology at UNT, he continues to study birds but he examines their developing cardiovascular and respiratory systems.

He has remained interested in studying birds because he wants to examine how environmental insults, or stressors, influence the development of their cardiovascular and respiratory systems. Even more, he's interested in studying how environment influences of development may have practical applications for humans.

For the cardiovascular system, Dr. Dzialowski has focused on the ductus arteriosus, a blood vessel that is found in the fetus. He's interested what causes the blood vessel to constrict and how certain conditions influence its closure.

His research could help provide insight on patent ductus arteriosus, which is when the blood vessel known as the ductus arteriosus doesn't close in an infant after birth. Patent ductus arteriosus can cause abnormal blood flow between two blood vessels - the aorta and pulmonary artery - that carry blood from the heart.

As a fetus develops in the womb, Dr. Dzialowski says, it only uses the placenta to exchange gases such as oxygen with the mother. It's not using the lungs.

In birds and mammals, blood leaves the pulmonary artery and then travels through the ductus arteriosus, which connects the pulmonary artery with the aorta. As a result, blood bypasses the lungs, and flows to the anterior portion of the body and into the placenta where it becomes oxygenated and then it comes back to the animal.

Dr. Dzialowski said humans have similar pathways in the cardiovascular system of birds. Both birds and mammals have have a ductus arteriosus.

"As soon as you're born, you want that blood vessel to close because now you're breathing through your lungs," he said. "You want fetal blood which would go from the pulmonary artery through the ductus and into the aorta, to now go through the pulmonary arteries and to the lungs."

Dr. Dzialowski said the ductus is a special type of blood vessel because it constricts when oxygen levels increase.

"There are only a few blood vessels that respond in such a manner," he said. "So the basic science is interesting - what is it that allows this blood vessel to do this whereas others don't do it.?"

Furthermore, he said humans who are born premature have a greater chance of having patent ductus arteriosus because the blood vessel isn't mature and therefore, it's not ready to close.

"So the question is how do you help close it?" he said. "But on top of this, if you're unfortunate and born premature in Denver rather than Dallas, then you have an even greater incidence of having a ductus that won't close. So the question is what is not fully mature at this point that doesn't allow the ductus to close?"

The National Science Foundation and American Heart Association have funded this aspect of his research.

Another area of his research focuses on the respiratory systems of birds and provides insight about the development of metabolism in humans.

Dr. Dzialowski said animals develop along a spectrum in terms of the way they control their body temperature. Birds and mammals are known as endotherms, which means they can physiologically regulate their own body temperatures.

Humans are endotherms because they have the ability to maintain a high constant body temperature by generating internal heat, he said.

For example, when it's cold outside, a person's metabolism will increase because they are generating more heat. However, during the summer when a person goes outside, they will sweat which enables them to regulate their body temperature. Both processes cost energy.

However, birds don't always start out as endotherms, he said. When they are in the embryo, they are ectotherms, meaning they rely on the environment to regulate body temperatures. However, shortly after the bird hatches, it becomes an endotherm.

Dr. Dzialowski said he's interested in what is changing and developing in the birds that allow them to go from ectotherms to endotherms. He's interested in changes occurring in the cellular processes, morphological features and physiological features.

Dr. Dzialowski said the applications of this particular research could provide insight into the development of metabolism and endothermy.

"How does metabolism develop?" he said. "What are the steps required for the development of metabolism? And you never know what basic science leads to. There are metabolic diseases that if we know how these things develop early on, then we may look at metabolic diseases."

He said the research is also important because it could lead to insight on the evolution of endotherms.

"The question, just scientifically is how, when, and why did endothermy evolve?" he said. "If we have a better understanding of its development that will allow us to make better predictions about its evolution."

Dr. Dzialowski said graduate students can benefit from the positive interactions between the labs in the Developmental Integrative Biology cluster.

"You're not joining just a lab," he said. "You're joining a larger family because everyone interacts with each other in terms of the graduate students and faculty."

He continued: "When you choose a graduate program, in a large sense, it should be for the people there. We've got a great growing group of folks here."

Dr. Dzialowski is a member of the Society of Integrative and Comparative Biology, American Physiological Society, Poultry Science Association and the Society for Experimental Biology and Medicine