many HIV patients used to do their own auto-insufflation using an often imprecise portable ozonator. In California, Carpendale et al (1993) were allowed to perform a study in AIDS patients with profuse diarrhoea due to opportunistic Cryptosporidium infection; as it was expected, they reported only a temporary improvement in some of the patients. The main field of application is represented by rhagases, anal and rectal abscesses with fistulae, proctitis, bacterial and ulcerative cholitis, Crohn’s disease and chronic B and C viral hepatitis. Even ischaemic diseases and dementias have been treated with RI, which was postulated to have a systemic effect. Indeed a surprisingly rapid systemic effect seems supported by recent studies in the rat (Leon et al., 1998; Barber et al., 1999; Peralta et al., 1999, 2000; Borrego et al., 2004; Gonzalez et al., 2004), in which it was shown that RI for two weeks induced adaptation to chronic oxidative stress. In spite of the fact that hundreds of thousands of treatments are performed every year, it was unclear whether and how these gases could affect some physiological, biochemical and immunological parameters. Although mainstream medicine, as usual, scorns this simple treatment, I feel it is important to address the following questions:

- 1) Are oxygen and ozone absorbed by the intestinal mucosa?
- 2) Does RI have only local effects or systemic ones as well?
- 3) Bearing in mind the toxic effects of ozone on the respiratory tract, we

must ascertain if ozone negatively affects the intestinal mucosa. Knoch et al., (1987) examined the PvO modifications after rectal 2 insufflation in the rabbit. They found increased oxygen content of 230, 121 and 127% in a mesocolonic vein, portal vein and liver parenchyma, respectively, 8-20 min after rectal insufflation of 150 ml of gas. The values returned to baseline after 50 min. This result is not new because we know 49 that several gases, such as carbon dioxide, methane, hydrogen, oxygen, nitrogen and hydrogen sulphide, either ingested or produced by the bacterial flora are partly absorbed or excreted or even exhaled with expired air. Obviously we are interested in the fate of ozone introduced in the gut lumen. In Chapter 4, it has been clarified that ozone, firstly dissolves in water but, unlike oxygen that freely diffuses into other compartments, reacts immediately with any biomolecule, particularly PUFA producing ROS and LOPs. Thus we can determine the fate of ozone by measuring LOPs in the intestinal-portal and peripheral circulation. While the respiratory mucosa is overlaid by a very thin and hardly protective film of fluids, the gut mucosa is abundantly covered by the glycocalyx and a thick coating of water containing mucoproteins and other secretion products with potent antioxidant capacity (Halliwell et al., 2000). Besides this gel-mucous layer, a variable faecal content is present and can quench the oxidant activity of ozone. It becomes clear that this unpredictable parameter represents the weak point of RI because we cannot ever be sure of the ozone dosage really available. However we felt worth while investigating in the rabbit whether ozone has, through the LOPs either a local, or/and a systemic activity. Results have been enlightening and have reported in extenso by Bocci et al., 2000 and Bocci, 2002. It suffices here to sum up the following data: 1) After rectal insufflation, we measured increased oxygen content both in the portal vein (20-35 min later) and in the jugular vein (35-40 min later). There were no significant variations of PvCO and pH. 2 2) Concomitantly, there was a constant increase of LOPs’ values up to 60 min after gas insufflation, when they started to decline. Values were markedly higher in the portal than in the jugular blood due to dilution