ISS Study Shows Hypergravity Counters Bone Loss in Mice

The International Space Station as it appears in 2018. Zarya is visible at the center of the complex, identifiable by its partially retracted solar arrays. (Credit: NASA)

Nature has a report about a Japanese study that showed 2G hypergravity causes increased bone and muscle growth in mice.

“We examined the influence of artificially produced 2G hypergravity on mice for bone and muscle mass with newly developed centrifuge device. We also analyzed the effects of microgravity (mostly 0G) and artificial produced 1G in ISS (international space station) on mouse bone mass,” according to the abstract.

“Experiment on the ground, the bone mass of humerus, femur and tibia was measured using micro-computed tomography (μCT), and the all bone mass was significantly increased in 2G compared with 1G control. In tibial bone, the mRNA expression of bone formation related genes such as Osx and Bmp2 was elevated,” the abstract added.

The abstract is below. Read the full story here.

Hypergravity and microgravity exhibited reversal effects on the bone and muscle mass in mice

Tsukasa Tominari, Ryota Ichimaru, Keita Taniguchi, Akane Yumoto, Masaki Shirakawa, Chiho Matsumoto, Kenta Watanabe, Michiko Hirata, Yoshifumi Itoh, Dai Shiba, Chisato Miyaura & Masaki Inada

Abstract

Spaceflight is known to induce severe systemic bone loss and muscle atrophy of astronauts due to the circumstances of microgravity. We examined the influence of artificially produced 2G hypergravity on mice for bone and muscle mass with newly developed centrifuge device. We also analyzed the effects of microgravity (mostly 0G) and artificial produced 1G in ISS (international space station) on mouse bone mass. Experiment on the ground, the bone mass of humerus, femur and tibia was measured using micro-computed tomography (μCT), and the all bone mass was significantly increased in 2G compared with 1G control. In tibial bone, the mRNA expression of bone formation related genes such as Osx and Bmp2 was elevated. The volume of triceps surae muscle was also increased in 2G compared with 1G control, and the mRNA expression of myogenic factors such as Myod and Myh1 was elevated by 2G. On the other hand, microgravity in ISS significantly induced the loss of bone mass on humerus and tibia, compared with artificial 1G induced by centrifugation. Here, we firstly report that bone and muscle mass are regulated by the gravity with loaded force in both of positive and negative on the ground and in the space.