Two-way ANOVA with repeated measures or one-way ANOVA was used as appropriate, followed by Dunnett's or Bonferroni's test for post hoc analysis when multiple comparisons were made. All data are expressed as means �� SEM, and P < 0.05 was considered statistically significant. The SBP measured in the tail artery in the conscious state and the MAP measured in the carotid artery under general anaesthesia were both in much higher 2K1C rats than in Sham rats (Table 1). There was DNA Damage inhibitor
no significant difference in the SBP and MAP among any subgroups within the Sham rats or within the 2K1C rats. No significant difference was found in body weight or baseline HR between Sham and 2K1C rats. Microinjection of a catalase analogue, PEG-CAT, into the PVN decreased increased the baseline RSNA and MAP, whereas the catalase inhibitor, ATZ, these parameters. The effects of PEG-CAT and ATZ were significantly greater in 2K1C than in Sham rats (Fig. 2A). In 2K1C rats, PEG-CAT induced immediate, slow and long-lasting decreases in baseline RSNA and MAP, peaking at approximately 15 min and lasting at least 60 min, whereas ATZ DDR1
caused immediate, rapid and long-lasting increases in baseline RSNA and MAP, peaking within 5 min and lasting at least 60 min (Fig. 3). Neither PEG-CAT nor ATZ had any significant effect on HR. The representative recordings shown in Fig. 4A illustrate that epicardial application of BK increased RSNA and MAP in 2K1C rats and that the CSAR was abolished by the PVN microinjection of 0.2 i.u. of PEG-CAT. The CSAR was enhanced in 2K1C rats compared with Sham rats. The PVN microinjection of PEG-CAT inhibited the CSAR in both Sham and 2K1C rats. The high dose of PEG-CAT almost abolished the CSAR. Although the CSAR was enhanced in the 2K1C rats, microinjection of ATZ into the PVN further augmented the CSAR (Fig. 2B). Intravenous injection or AHA microinjection of the high dose of PEG-CAT had no significant effect on the RSNA, MAP and CSAR. No obvious effects were observed in rats whose microinjection sites were outside the bilateral PVN. Microinjection into the PVN of l-glutamate increased the RSNA and MAP (+17.5 �� 3.2% and +7.4 �� 1.3 mmHg, respectively). Pretreatment with PEG-CAT had no significant effect on the RSNA and MAP responses to l-glutamate (+16.1 �� 4.9% and +6.1 �� 1.7 mmHg, respectively). Angiotensin II microinjected into the PVN Temozolomide
increased RSNA and MAP in both Sham and 2K1C rats. The effects of Ang II were greater in 2K1C than in Sham rats. Pretreatment with PEG-CAT in the PVN inhibited the effects of Ang II on the RSNA and MAP in both 2K1C and Sham rats. The high dose of PEG-CAT almost abolished the effects of Ang II. However, ATZ microinjected into the PVN failed to enhance the effects of Ang II on the RSNA and MAP (Fig. 5A). The RSNA and MAP before the pretreatment with saline, PEG-CAT and ATZ and before the subsequent PVN microinjection of Ang II are summarized in Table 2.