HTR1A and Bradycardia: In long-term diabetic rats, we noted that the increases observed in the vagally induced bradycardia after administration of low doses of 5-HT and 5-CT (selective 5-HT1/7 receptor agonist) were mimicked, at all stimulation frequencies, by the selective 5-HT1A receptor agonist 8-OH-DPAT [45].