Overview
- Ireland, S.J. and Tyers, M.B. (1987) Br. J. Pharmacol. 90, 229.
Alomone Labs 1-Phenylbiguanide hydrochloride activates 5-HT3A receptors expressed in HEK 293T cells.Currents were elicited by 10 or 100 µM 1-Phenylbiguanide hydrochloride (#P-190), as indicated. The currents that were elicited by this agonist were comparable in amplitude to the cells response to 10 µM 5-HT (not shown here).
Phenylbiguanide (PBG) acts as an agonist of 5-HT3 receptors, with an EC50 value two fold greater than that of 5-HT and was found to imitate the effects of 5-HT on mammalian peripheral neurons. PBG causes dopamine release and has been used in many studies as a selective agonist to arouse reflex bradycardia and hypotension through activation of cardiac and pulmonary vagal afferents1,3.
For over 40 years, PBG has been used as a selective agonist to identify cardiac and pulmonary vagal C fibers and the associated reflex bradycardia and depressor responses. It is capable to stimulate cardiac chemosensitive receptors with vagal afferent pathways and the sensory nerves in different regions of the body3.
In one study conducted in rats, it was found that phenylbiguanide depolarizes the rat vagus nerve and mimics the effects of 5-HT on the vagus nerve. In addition, it was shown that phenylbiguanide causes reflex falls in heart rate and blood pressure in the cat and induces pain following application to the bases of blisters in human subjects1.
It has been documented that right atrial bolus injection of phenylbiguanide can stimulate bronchopulmonary C-fibers that play an important role in modulating the respiratory rhythm to produce apnea2.
