Peripheral 5-HT _1A and 5-HT ₇ Serotonergic Receptors Modulate Parasympathetic Neurotransmission in Long-Term Diabetic Rats

Figure 1

Change in heart rate response (ΔHR) evoked by electrical stimulation of the peripheral end of the right vagus in atenolol (1 mg/kg), pretreated (a) normoglycaemic and (b) four-week diabetic pithed rats before (control; 𝑛=5) and after i.v. administration of a bolus of 1 mL/kg saline solution or 10, 50, 100, 200 μg/kg of 5-hydroxytryptamine (5-HT) to normoglycaemic rats (𝑛=5) or 10, 50, 100, 200 μg/kg of 5-HT to four-week diabetic rats (𝑛=5). *𝑃<.05 compared with saline (control).

(a)

(b)