Scientists in Shanghai, China have managed to impregnate male rats in a controversial new experiment. The animal testing raised concerns about ethics and animal cruelty.
In the study, researchers sewed castrated male and female rats together by their knees, elbows, and skin. By doing this, the animals were able to share blood.
The study included 46 conjoined pairs of rats.
The male rats’ levels of testosterone had ‘significantly declined’ by six weeks, Nature wrote. Meanwhile, their levels of oestrogen and progesterone were similar to that of the female rats.
The researchers transplanted a uterus into the male rats eight weeks after surgery. Eight weeks after that, they transplanted embryos, too.
The scientists delivered the pups by caesarean section. Of the 280 embryos implanted in the male rats, 3.68 percent survived to adulthood – 10 pups in total.
‘No social value’
Qiu Renzong is a bioethicist at the Chinese Academy of Social Science in Beijing. According to China Daily, Renzong was the first to introduce bioethics to China more than 40 years ago.
“The experiment has no social value and just wasted the money taken from taxpayers,” he told Nature.
The study authors wrote that their research could have ‘a profound impact on reproductive biology’.
But contrastingly, study co-author Rongjia Zhang said the research was conducted ‘for our personal interests and curiosity’.
“Please stop associating the rat model with humans. They are completely different,” he said.
“Male pregnancy in humans is not feasible at this stage,” Zhang wrote on PubPeer. “If our result is correct, this is almost a death sentence for human male pregnancy.”
PETA Senior Science Policy Advisor Emily McIvor called the experiment ‘disgusting’.
“Animals should not be produced in labs, experimented on, or treated as throwaway things; they deserve to be respected and left alone,” she said to Mail Online.