Chinese doctors, working in a laboratory in Northeast China, have succeeded in nurturing an in vitro embryonic human heart the size of a grain of rice for 35 days.
The tiny human heart was still beating as of 9 am yesterday, at a rate of 20 beats per second, according to doctors with the procreation center laboratory of the Women and Infants' Hospital in Shenyang, capital of Liaoning Province.
The case is a first in the world, doctors said.
Qu Wenyu, president of the hospital, says the heart is growing well and taking on the shape and structure of an adult heart. "The ventricle and atrium of the miniature heart are beating synchronously," said Qu.
The ventricle of the tiny heart initially beat at between 18 and 22 times, and the atrium, 60 to 80 times per second, explained Qu, adding that he and his colleagues are still mystified by the early slower heartbeat.
"Compared to a normally developed embryonic human heart, this heart is much smaller in size and lacks the perfect structure and functions of a normal embryonic human heart," said Wang Tong, who is in charge of the research.
The heart was removed from a 52-day old aborted foetus. On June 5, Wang removed it from the embryo and placed it into a culture dish in the procreation laboratory.
When he returned the next morning, June 6, he was thrilled to find the tiny heart beating strongly, and he observed, through a microscope, that the cells of the heart were breaking up.
"This showed that the heart was growing," Wang said excitedly.
Prior to the culturing - maintaining cells in conditions suitable for growth - of this human heart, research of this type in China had only been conducted on peacocks, fish and mice, according to scientific documents provided by the Liaoning Provincial Science and Technology Information Research Institute.
Significantly, to date there is no record of the survival of in vitro embryonic human hearts anywhere in the world, according to the research institute.
Wang said that his laboratory has been conducting research on protogonocytes in the genital ridge, hoping to obtain stem cells to enable cloning of human body organs and parts such as lungs, livers, eyes, hands and stomachs.
(China Daily July 11, 2003)
