| rat developmental |
Developmental |
The procedure for natrium fluoride (NaF, SIGMA Aldrich, Italy) administration was fully described in the paper from Bera et al. [“Starting from day 1 of gestation and daily through postnatal day 9, experimental female rats were administered, by intragastric gavage, a solution of sodium fluoride (NaF, Novartis S.p.a., Origgio, VA, Italy) dissolved in deionized water. Drinking water was deionized water throughout the study. Preliminary experiments were performed with the following experimental groups: 1) undisturbed animals (no gavage at all); 2) 1 ml/kg of deionized water by gavage; 3) solution containing NaF 2.5 mg/kg/ml dissolved in deionized water by gavage; 4) solution containing NaF 5.0 mg/kg/ml dissolved in deionized water by gavage. Once comparisons between first and second group gave no statistical differences in all tests performed during the preliminary part of this research, which considered doses up to 20 mg/kg/ml, the treatment schedule was set up without the control group which was scheduled without any manipulation (gavage). Doses over 10 mg/kg were not considered due to the detection of some structural anomaly found in the offspring. Consequently, the doses of NaF employed in the present study were 2.5 and 5.0 mg/kg which respectively correspond to the upper level and twofold greater than the concentration level of the fluoride recommended dose (1,2 mg/ litre in drinking water).”]; Animal experimentation was performed in accordance with the EU directive 86/609 EEC, with the guidelines released by the Italian Ministry of Health (D.L. 116/92 and D.L. 111/94-B), with the UK Animals Act 1986 and associated guidelines and with the “Guide for the Care and Use of Laboratory Animals”, as adopted and promulgated by the National Institutes of Health (USA). According to the above guidelines, all efforts were made to minimize the number of animals and their suffering. Primiparous Wistar female rats (Harlan SRC, Milan, Italy), weighing 200-260 g were used. Animals were allowed free access to food and water, housed at constant room temperature (20-22 deg C) and exposed to a light cycle of 12 h day (08:00-20:00 h) for 2 weeks before the experiment. Pairs of females were placed with a single male rat in the late afternoon. Each female rat was inspected for vaginal smears on the following morning at 09:00 h. The day on which sperm were present was designated as day 0 of gestation. On the day following parturition (PND 1), 10 litters for each experimental group were reduced to a standard size of four male and four female pups per litter, when possible. All pups were tested on PND10 for UV and on PND 90 for ASR and PPI evaluations. |