Truth, unlike a meal, can be hard to swallow

More animals are eaten at the average conference dinner than were used in experiments that resulted in drugs that saved millions of people's lives. John Vane urges us to put vivisection into perspective and place our rights before those of other species.

It is our ability to learn from the experiences and experiments of others that is the essence of scientific understanding and progress. Many new concepts, leading to powerful new medicines, have been developed through the use of animals in research.

In the early 1600s, William Harvey discovered the circulation of blood. It is difficult to quantify the vast amount of knowledge and understanding that has stemmed from this discovery. He experimented on many species, sometimes with great simplicity. For instance, he exposed the heart of a live snake and noted that forceps, when placed on the great vein, led to a pallid, empty heart, whereas when placed on the arterial side caused the heart to become engorged with blood. Imagine the excitement of noting this for the first time, together with the realisation of what it meant.

Since Harvey's discovery of the circulation of blood, generation after generation of biologists has created mountains of knowledge about how the body works. Think of the deficit, the deprivation, the dearth, the damage and suffering that would have ensued had this discovery not been made. Does it upset you that scientists use snakes for their experiments? If the answer is "No, after all, it's only a snake", just where do you draw the line?

For my part, I am very comfortable with distinguishing between man on the one hand and all other species on the other. It is our ability to accumulate past experience in the forms of writings, art, scientific papers and verbal communication that sharply and uniquely distinguishes us as humans from the rest of the animal kingdom. We must distinguish between humans and the beasts, birds and bugs of this planet.

We must be more concerned with human rights than with animal rights. Human victims of disease, of rapists, muggers, bombers and terrorists cry out for our attention, as do the starving millions of African children. Conversely, if I am buzzed by a mosquito, I take a swipe at it in the hope that I can prevent it from causing me unnecessary suffering. With the proviso that animal welfare is properly considered, I am comfortable in using other species as beasts of burden, for food, clothing or for animal experiments. I am also comfortable in destroying those species that threaten man and his domestic animals, such as disease-carrying vectors, vermin, parasites, bacteria and viruses.

Bioassay, the science of making quantitative biological comparisons, has its roots in ancient history when man began to use handy bits of his own body to make measurements. The foot, the hand, the palm and the digit are all self-explanatory. The cubit was the length of the arm from the elbow to the fingertips, whereas the fathom was the distance between the fingertips of the outstretched arms, interestingly approximating to height. The definition I like best is the furlong, which was the length of a furrow ploughed by a team of oxen between rests.

Using bioassay methods, I discovered in 1971 that aspirin and other anti-inflammatory drugs inhibited the enzyme cyclooxygenase (Cox), which makes the ubiquitous messengers, the prostaglandins. I proposed this as an explanation of both their therapeutic effects and their side-effects. We know now that there are two enzymes, Cox-1 and Cox-2, and that Cox-2 is the important one to inhibit for an anti-inflammatory effect. Safer anti-inflammatory drugs have now been developed that spare Cox-1, which makes the prostaglandins needed to protect the stomach lining.

We also discovered prostacyclin, made by the endothelial cells that line the blood vessels and help to keep them clean, preventing platelets from sticking to them to form clumps and thereafter thrombosis. We developed prostacyclin as a drug, and it has found a use in obstructive vascular disease, especially in primary pulmonary hypertension.

Another area of interest to my research group was peptides. In 1964, Sergio Ferreira came to my laboratory, carrying in his pocket an extract of the venom of the Brazilian snake Bothrops jararaca . We showed that the enzyme that converts angiotensin I to angiotensin II (ACE) was inhibited by this extract. By a tortuous pathway, well documented, these experiments led to the discovery of the first ACE inhibitor, captopril.

In 1988, Sir James Black, Gertrude Elion and George Hitchings received the Nobel prize in physiology or medicine for "their discoveries of important principles for drug treatment". The clutch of novel drugs they invented- betablockers, H 2 antagonists, antibacterials, antimalarials, gout-suppressants and immunosuppressants - have brought about a substantial improvement in the quality of life of tens of millions of people and saved millions of others from death. The cost in animals used for all this type of research is far lower than the cost of those eaten, collectively, by persons attending a conference dinner. The cost-to-benefit ratio in terms of suffering is easily calculable, verifiable and overwhelmingly acceptable to all those concerned with the improvement of the human condition.

What about the anti-vivisectionists? They have, with some success, allied themselves to environmental issues. It is unfortunate that their arguments are now presented to our children as "green", which they clearly are not. This inappropriate positioning is wrong and should be vigorously countered. There has been, and will be, an enormous world of discovery deriving from animal experiments. Should the anti-vivisectionists succeed in their ambitions to stop animal experiments now, our children will be denied the medicines and cures arising from today's discoveries, which they have the right to expect in the next ten-20 years. But we cannot just leave it there. My own perspective of the anti-vivisectionists is that they should be positioned, not with environmental issues, but with other zealots of extremist attitudes. The conventional elements, such as science, logic and civilised behaviour, have to counter sinister elements, such as the destructive cults, quackery, anti-vivisectionists and terrorism. Those who advocate only the use of alternative methods belong with those who peddle alternative medicines and alternative religions, proselytising as they do from the basis of belief, faith and mystique, rather than from the basis of proven and established facts. It is an unacceptable facet of modern-day society that scientists who have worked all their lives to enhance the quality of life, to prevent suffering and distress and to combat disease should have to be advised to kneel at the end of the day, not to pray, but to inspect the undersides of their cars for terrorist bombs.

Sir John Vane FRS was awarded the Nobel prize for medicine or physiology in 1982.

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