Expression of parvalbumin (PV) and transient receptor potential
vanilloid (TRPV1) receptors in the lumbar dorsal root ganglion
neurons (DRG) was evaluated in control animals and in rats after
acute carageenan-induced knee joint inflammation. PV is a
calcium binding protein that acts as a calcium buffer, affects
intracellular calcium homeostasis and may thus influence signal
transduction and synaptic transmission. TRPV1 receptors are
viewed as molecular integrators of nociceptive stimuli and
modulate spinal cord synaptic transmission beside their function
in the peripheral nerve endings. In naive rats, 13 % of the L4
DRG neurons had PV immunopositivity (PV+) and 36 %
expressed TRPV1 receptors (TRPV1+). The soma of the PV+
neurons was of medium to large size, while the TRPV1 receptors
were expressed in small diameter neurons. The co-localization of
the PV and TRPV1 immunoreactivity was minimal (0.2 %). There
was no significant change in the PV+ (11 %), TRPV1+ (42 %)
and PV+TRPV1+ (0.25 %) expression, or shift in the neuronal
size distribution 28 h after the unilateral peripheral inflammation,
both when compared to controls and when ipsilateral to
contralateral sides were evaluated. Thus under the given
experimental conditions, no change in somatic TRPV1 receptors
and PV expression in L4 DRG neurons was found.
Suppression of P2X3 receptor‐mediated currents by the activation of α
2A
‐adrenergic receptors in rat dorsal root ganglion neurons
