90-Day Inhalation Study with Cigarettes containing G7-25 The only invasive techniques to be used by first anesthetizing with 70% CO: 2 in air and in the experiment (other than necropsy: see then exsanguination prior to cessation of below) are-related to tattooing and blood heartbeat. Only personnel approved by the sampling. Tail-tattooing will be performed laboratory veterinarian will be allowed to under light anesthesia with 70% carbon perform this procedure. dioxide (CO2) in air, by certified operators. Hazardous Materials Blood samples are required from There is no evidence to suggest that the animals at the end of their daily inhalation test compound is in any way hazardous and exposures, to verify the blood concentrations consequently there are no special requirements of carboxyhemoglobin (COHb). The latter are for animal care personnel. Disposal of soiled required to ensure that animals do not die from bedding and animal carcasses need only follow hypoxia (Ayres et al., 1989). The blood routine procedures. samples obtained are also used to assess dosimetry, by providing plasma concentrations EXPOSURE REGIMEN of nicotine and cotinine. Cigarettes The procedure involves light anesthesia The test and reference cigarettes will be with 70% CO 2 in air, followed by blood uniquely identified, and will be stored under sampling from the retro-orbital sinus. Only conditions recommended by the G7-25 skilled personnel approved by the laboratory research team. veterinarian will be allowed to perform this Smoke Dilutions technique. There are no known side-effects of Smoke dilutions will be confirmed by this procedure. assays made in the breathing zones of the Survival Surgery inhalation chamber before any animals are No surgical interventions are planned exposed to smoke. In particular, the carbon during the in-life phase of the experiment, and monoxide (CO) concentrations will be so no survival surgery is scheduled. compared with the known toxicity for this Any animals that die during the smoke component (Ayres et al., 1989). experiment will not be replaced, nor will any The dilution air will be passed through a attempts be made to treat any moribund Del-Monox compressed air purification system animals (see "Viability checks" and (Deltech Engineering, New Castle, DE) and "Euthanasia", below). humidified before being presented to the Pain/distress animals. The exposure atmospheres will have An integral part of the study is the an RH of 40-60%, with a temperature of restraint of the animals in nose-only exposure 20-24°C. tubes and in whole-body plethysmographs (see The approximate WTPM exposures to below). This restraint is inevitably stressful to be used in the study, expressed as milligrams the animals. Previous work has shown that per liter of air presented, are as follows : low this stress is minimal, and that animals exposure, 0.16, medium exposure, 0.32, and continue to gain weight throughout a 90-day high exposure, 0.64. These latter exposures study similar to that described here (Coggins have been shown to be tolerated in earlier et al., 1989 a, b). The restraint tubes have a experiments (Coggins et al., 1989 a, b). number of features which minimize stress, Exposure Duration. such as ventilation holes and channels for the Each exposure group will be exposed to removal of urine and feces (Baumgartner & smoke for 60 minutes, once per day, 5 days per Coggins, 1980). The tail of the animal is not week, for 14 consecutive weeks. The total restrained, which is thought to reduce elevated number of exposures will be 65 for each of the temperatures in the tubes. groups. The low, medium and high exposures Animals are only placed in will be "stagger-started" by one day. A plethysmograph tubes (where ventilation, portion of the surviving animals at the end of drainage channels and unrestrained tails are the 90-day inhalation study will be kept for an not possible: see Coggins et al., 1981) for 1-2 additional 14 weeks without treatment. These exposures during the study. animals will be used to evaluate the Euthanasia reversibility of any changes observed after 90 Animals will be weighed and then killed days. DRAFT: DO NOT QUOTE. Page 3 Source: https://www.industrydocuments.ucsf.edu/docs/ffbb0103