Tag Archives: cardiovascular

Beats & Breathing
Thomas Asama
Senior
Human physiology major
University of Iowa

My Research Project

Healthy amounts of oxygen are necessary for almost every tissue in the body. Refined mechanisms function to keep oxygen levels within healthy and functioning ranges. A key player in this oxygen regulation, known as the peripheral chemoreflex, acts to sense oxygen in the blood by way of the carotid bodies. Carotid bodies are small structures located next to the carotid arteries in the neck. When the carotid bodies sense that oxygen levels have fallen below normal values, the body responds by activating the sympathetic nervous system (SNS).

The SNS responds to many different bodily stressors and works to increase oxygen uptake to restore oxygen levels. Diseases, however, can disturb this carefully calibrated system. In obstructive sleep apnea (OSA), for example, the airway becomes blocked periodically during sleep, resulting in episodic cessations of breathing and consequential drops in oxygen levels. These frequent periods of low oxygen can cause two issues: first, increased stimulation of the carotid bodies also increased their sensitivity so that normally nonproblematic decreases in oxygen can trigger their activity; second, increased frequency of low oxygen periods and increased sensitivity of the carotid bodies result in an overactive SNS.

The SNS is one of the body’s general response pathways and works to increase oxygen levels while simultaneously increasing blood pressure. Overactivity of the SNS can lead to chronic high blood pressure which places individuals at risk of stroke, heart failure and many other health issues. By looking for possible ways to alleviate these issues, some animal research has suggested that the molecule nitric oxide (NO) has the ability to desensitize the carotid bodies. Additionally, significant literature has demonstrated that supplementing nitrate (NO3) serves as a way to increase NO availability in the body. Our study intends to assess if supplementation of nitrate in the form of beetroot juice has the ability to decrease the sensitivity and over-responsiveness to low oxygen levels in patients with OSA. Beetroot juice is a relatively cheap and readily available supplement and provides an easily accessible treatment for the general population. If a strong correlation is found, this study will open the field to further research projects pursuing beetroot juice supplementation as adjunct therapy to decrease high blood pressure in the OSA population.

Realities of Research

Research is the epitome of the ability to be dynamic; no complication or problem has one solution. A general image of research provides an image of a lab coat-clad scientist in a sterile silver lab with seemingly perfect and exact run experiments. However, while strongly ordered and rational, the research was often far more less sterile than I had originally planned. Because I was working with human research, a large part of my time in the lab was dependent on recruiting subjects. We had various study days throughout the summer working on collecting data for analysis. I quickly realized there wasn’t one way to view or process our results. I spent many hours spent organizing and reorganizing data in excel, trying to find the best way to compare the different data sets we had been collecting. As the summer went on, I found cleaner and clearer ways to assess and group the data we collected. Ultimately, a large portion of research functions as a product of experience. This summer’s fellowship provided significant time where I could devote myself specifically to this end.

Life as a Scientist

Some children say they want to be an astronaut or a ballerina, and then the nerdier contingent always goes for scientist. Yet, it is seldom true that we know what that kind of life entails. I was amazed by the endless room for growth. On a broader level, there was a vast range of autonomy working and planning as a scientist. What were the next steps? How did today’s data play into the future’s experiments? Each possibility demanded a pursuit of deeper knowledge and expertise in the field. I had the opportunity to attend several research presentations throughout the summer and was constantly amazed by the level at which the professors and researchers considered and analyzed the presentations.

While the opportunity to learn was constant, I was not a fan of the variability of pace in the lab. A big part of this is unique to human research, but the recruitment process meant that some weeks we had no studies and others we had seven or eight. This made it difficult to routinize my work, as each week was different from the last. Nonetheless, during my time in the lab, I had significant opportunities to discuss the content and implications of our research with others. Having this opportunity to discuss physiology solidified my understanding and clarified my misunderstandings of many topics. Likewise, working as a team, each member made up for and filled the needs of others on the team. In this way, together we strove for excellence and efficiency throughout the summer. 

References:

Beets, Border, Diet [Online]. Prexels. https://www.pexels.com/photo/beets-border-diet-food-533298/ [16 Jul. 2019].

Thomas Asama is in his final year of pursuing a bachelor of science in human physiology at the University of Iowa in Iowa City. His undergraduate research experience has been under the mentorship of Dr. Darren Casey, Human Integrative Cardiovascular Physiology Laboratory in the department of physical therapy and rehabilitation science at the University of Iowa. Thomas received funding for his summer research as an Undergraduate Summer Research Felllow (UGSRF) from the American Physiological Society. After completing his undergraduate studies, Thomas plans to attend graduate school for a doctorate in physical therapy, with hopes of pursuing a career in clinical physical therapy.

Blood Flow and Other Bodily Functions: An Investigation of Vascular Function and Endurance Sports
Andrea Rico
Junior, Health Sciences
University of Texas at El Paso
2019 STRIDE Fellow

My Research Project

My research project was focused on measuring the vascular function and rate of blood flow in arteries of the upper and lower body extremities using flow- mediated dilation (FMD) and plethysmography. We investigated the differences in vascular function on endurance sports that are upper-body predominant, lower- body predominant and mixed combination. FMD is an advanced test that uses ultrasound to measure dilation changes in the diameter of arteries, such as those in the forearm. This is a method to assess the endothelial vascular function in humans. Plethysmography measures changes in volume of blood in different extremities like the upper- or lower-body extremities. These changes are measured with blood pressure cuffs attached to a machine known as the plethysmograph. This test can dictate the amount of blood flowing through the limb and time where peak blood flow happens. It is highly effective when it is used to find changes caused by blood flow. An endurance sport is any sport that has prolonged periods of physical stress. Swimming, for example, combines both cardio and light strength exercises mostly in the upper body, which trains the body to use oxygen more efficiently. Cycling combines both cardio and light strength exercises mostly in the lower body, increasing leg strength and endurance. American football involves a lot of resistance training in both upper and lower extremities. Comparing vascular function and structure in these three sports can help to determine specific changes with training modalities.

Realities of Research

This is my first time working in a lab and my first real research project, so it was pretty scary at first. However, as time passed, I started learning something new every day, including new techniques and skills. I slowly began to understand more about my project and its importance. It has been very exciting to be able to work on this project and being able to see the results.

Life as a Scientist

Working in a lab and being able to work with individuals who share the same passion has truly being an extraordinary experience. One of the greatest things that I personally have witnessed is seeing how all lab members collaborate with one another and help each other out. It has truly been an unforgettable experience to get to know everyone and share endless memories with one another. I love being part of a lab!

Andrea Rico is a junior at the University of Texas at El Paso majoring in health sciences. She is a 2019 Short-Term Research Education Program to Increase Diversity in Health-Related Research (STRIDE) Fellow working in Dr. Gurovich’s lab. Andrea’s fellowship is funded by the American Physiological Society and through a grant from the National Heart, Lung and Blood Institute (Grant #1 R25 HL115473-01). After graduation, Andrea hopes to pursue a PhD in occupational therapy and work at a local hospital or practice.