Commonly, astronauts stay in space for a more extended period of time, and NASA is planning longer missions to the Moon and Mars. Researchers say that we need to understand better the effects that microgravity has on the heart.
Studies have shown that spaceflight can reduce heart rate and the lower arterial pressure, and can also increase cardiac output. However, new research shows how microgravity – zero gravity – has an impact on the human heart when it comes to the cellular level.
Scientists have been able to check the health of astronauts while they were in space, which was a great way to understand the molecular cell changes. This comes from Joseph C. Wu, from Stanford University’s School of Medicine. He is the author of the study.
The health of humans can be sustained for about a year in space, says NASA. When trying to answer this, researchers from Stanford University have taken a look at the cardiac function and at the gene expression in the human heart cells from three people. The cells did not come from biopsies, but they were made by reprogramming a sample of blood into the human stem cells. Then, the heart cells were cultured abroad the International Space Station for around 5 weeks. This is the first study of this kind.
Scientists found that the exposure to microgravity changed the expression of 2.635 genes, which was a temporary change in the RNA, that is made from DNA. Most of them returned to the normal patterns of gene expression in about 10 days after coming back to Earth. RNA is a temporary and handwritten copy of the DNA. So the gene expression was temporarily changed by the environment – microgravity. The changes were subtle, but they were still significant.