Pigs are occasionally used in toxicity and pharmacology studies in European countries but rarely in Japan. On the other hand, in pharmacology studies, pigs have been used in skin irritation and absorption tests as one of the alternate animals. However, in recent years, the production of min-pigs maintained under the quality management has been established in Japan and these animals are used actively in each field. The accumulation of the basic data for mini-pigs increases steadily and pigs are used while confirming whether the projects can be correctly conducted only in pigs each time.
Pigs (including training pis) weighing about 10 mg - about 100 kg can be obtained as experimental animals. The body weights of these animals are within the range of human body weights and the conditions capable of coping properly with various variations such as thickness of the blood vessels, size of the visceral organs, load on the joints can be satisfied in pigs. Therefore, pigs are useful animals in preclinical studies. Pigs are remodeling animals showing the bone metabolic turnover similar to that in humans. Since the implantation of bones into the long bones is actively conducted, soft bones such as meniscus and intervertebral disc are actively used in these animals and the sizes of these bones are appropriate for performing the surgical treatment, the use of pigs is more recommendable than that of rabbits, dogs and monkeys and pigs have advantages in evaluating the test substance clearly over the other animals.
In the field of dentistry the use of pigs are also gradually started but since there are still difficulties in obtaining appropriate thickness of the skull and extracting the teeth, the preparation of animal models and the evaluation of the test substance are now in the process of trial and error.
As for the visceral organs, pigs are actively used in the field of transplantation and especially in the circulatory system, kidneys and vascular system. In the extrapolation to humans, many organs of pigs are similar to those of humans in eating habits and anatomical features and are similar to those of humans in the size of organs. Therefore pigs are highly useful in preclinical studies.
On this occasion, we would like to investigate the usability and usefulness of pigs further through the introduction of part of cartilage regeneration test, bone implantation test and validation test for prevention of visceral adhesions which are performed in our Tsukuba Research Center.