Paula MacKinnon is surrounded by scepticism. Her elderly parents oppose her and many of her friends insist she is being foolish. Yet she is unrepentant. “I just don’t see it as a big deal,” she says, shrugging her narrow shoulders. “Y’know, welcome to my kidney. I want to donate it.”

Sitting in the kitchen of her modest home in a Glasgow cul-de-sac, she appears perfectly conventional. But her decision to donate a kidney to a total stranger makes her a first in Scotland.

It began when her 68-year-old mother, Katherine, suffered kidney failure last year. MacKinnon put herself forward as a potential donor, only to find that their blood groups were not compatible. Instead of stopping there, however, she decided to donate one of her kidneys to whoever might need it.

It is called altruistic donation and it was made possible by the introduction of the Human Tissue Act in September 2006. Previously, living donors were only allowed to give their organs to those who were genetically or emotionally related, such as family or spouses. Now, under the control of the Human Tissue Authority, donors can provide organs to people they do not know. As far as MacKinnon is aware, only 11 people in the UK have donated kidneys in this way, none of them from Scotland.

“There’s this huge thing about organ donation, that it still seems unusual,” she says. “If it becomes more acceptable in society, what I’m doing won’t be so shocking. There’s still a terrible shortage of organs. That’s what got me riled. In some ways, it’s a simple thing to do, to donate an organ, but it can make a huge difference to people’s lives.”

She is puzzled that her mother, who still needs a kidney transplant, is opposed. Her father, Kenneth, a minister, has also tried to talk her out of her plans. “Determined” is the word MacKinnon reaches for when she considers her own response, but she understands their anxiety.

“It’s because my parents care. I’m their daughter and I’m going through an operation I don’t have to go through,” she says. “I think, ultimately they think what I’m doing is good, but like any parent they’re concerned. They’ve given up , because it’s something I really want to do.”

Sitting quietly in the living room next door, listening to music, is Paula’s husband, Colin. Perhaps more than anybody else, he knows how the grain of his wife’s character runs. “He’s supportive,” says MacKinnon. “You can ask him.”

He understands, because it is not the first selfless act that she has undertaken. Both are BBC journalists and when he worked on a programme about orphaned children in Ukraine two years ago, his wife was moved to take 12 months’ unpaid leave and self-fund a three-month trip to the country to help.

So when asked what her motivation is for undergoing invasive surgery that requires a general anaesthetic, the insertion of a urinary catheter and a drip, and is followed by at least three or four days in hospital, her reasoning is succinct.

“It’s completely simple. It’s just something that I can do to help somebody else,” she says. “I’d got into the mindset of doing it for my mother. When I realised I couldn’t do it for her, I started to think I could do it for somebody else. So I researched it. They call it altruistic, but I am quite selfish. I wouldn’t do it if there was any harm to myself. The risks involved seem minimal compared to what I can give to somebody.”

She is 35, healthy and fit — a perfect candidate. She knows this because the assessment procedure for potential donors is painstakingly thorough. So much so that she has become frustrated. It is 10 months since she made her decision and she has been subjected to a battery of physical and psychological examinations, but still she must wait.

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