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Furthermore, pharmacological studies suggest expression of
purinergic receptors P2X
3
and P2Y
2
in Ho-OSNs. Purinergic
signaling suppressed odor-evoked responses. Alleviation of P2X
3
suppression by P2X
3
antagonist RO3 increased H-evoked responses
to 200% of its original level. However, RO3 did not change
Ho-evoked responses. In summary, our study showed ligand-
dependent functional selectivity and modulation of olfactory
receptor activity. For the first time, we have provided evidence of
complex signaling and modulation mechanisms in olfactory
transduction through conformational changes of an olfactory
receptor, which has important implications to understand the
mechanism of G-protein coupled receptor activation.
#P42
POSTER SESSION I:
MULTIMODAL RECEPTION;
CHEMOSENSATION & DISEASE;
TASTE PERIPHERY; OLFACTION PERIPHERY
drOlfCc1 is an Amino Acid Receptor with the Highest
Responsiveness to Isoleucine
Chunbo Zhang
1
, Yiqun Yu
1
, Chen Tian
1
, Hiroaki Matsunami
2
1
Illinois Institute of Technology Chicago, IL, USA,
2
Duke University Medical Center Durham, NC, USA
The repertoire of olfactory receptor genes comprises five different
families, the rhodopsin-like odorant receptors (ORs), vomeronasal
receptors (V1Rs and V2Rs), trace amine-associated receptors
(TAARs) and formyl peptide receptors (FPRs). Zebrafish olfactory
receptor drOlfCc1 is an ortholog of the mammalian V2R2 gene that
is broadly expressed in the olfactory epithelium. It belongs to the
“C family” of G-protein coupled receptors (GPCRs). The full
coding sequence of drOlfCc1 was cloned into the pCI based
expression vector. A Rho tag encoding the first twenty of
N-terminal amino acids of rhodopsin was attached in frame ahead
of the drOlfCc1sequence. The expression vector was transfected
into the Hana3A cell line, a modified HEK293 cell line that stably
expresses Gα
olf
and receptor transporting proteins. Expression of
drOlfCc1 in Hana3A was confirmed by immunolabeling of the
Rho tag to visualize the olfactory receptor protein.
Immunocytochemistry revealed that the olfactory receptor was
integrated into the surface membrane of cells. Deorphanization of
drOlfCc1 was conducted in Hana3A cells by coupling the receptor
activity with transients of cAMP-dependent firefly luciferase
reporters. Luciferase assay in Hana3A cells showed that
drOlfCc1 was sensitive to several amino acids with the highest
responsiveness to Isoleucine, followed by methionine, leucine,
alanine, phenylalanine, histidine, and tryptophan when tested at
200 µM. Other twelve amino acids tested were nonstimulatory.
In conclusion, drOlfCc1 is an amino acid receptor mainly sensitive
to a few neutral amino acids. Its receptive profile is narrower
than a well characterized zebrafish olfactory receptor drOlfCa1.
Acknowledgements: Supported by NIH/NIDCD grant DC011650.
#P43
POSTER SESSION II:
TRIGEMINAL SYSTEM; TASTE CNS;
NEUROIMAGING; OLFACTION CNS
Assessment of intranasal trigeminal chemosensitivity in
patients with olfactory dysfunction
Yongxiang Wei
1
, Ling Yang
2
, Yuanyuan Ren
1
, Yichen Guo
1
,
Kunyan Li
1
1
Department of Otolaryngology Head & Neck Surgery, Beijing
Chaoyang Hospital, Capital Medical University Beijing, China,
2
Center Laboratory, Beijing Tongren Hospital, Capital Medical
University Beijing, China
Objective
To investigation intranasal trigeminal sense changes in
patients with postviral olfactory dysfunction (PVOD) and post
traumatic olfactory dysfunction (PTOD).
Methods:
A total of 90
participants (30 healthy subjects, 30 patients with PVOD and 30
patients with PTOD) aged 20 to 70 years. Their chemical sensory
functions were examined using T&T olfactometer, trigeminal
event-related potentials (tERPs).
Results:
Patients with olfactory
dysfunction showed higher thresholds than healthy subjects.
Compared to controls, N1/P2 latencies of tERPs increased and
amplitudes decreased in patient with olfactory dysfunction. Patients
with PTOD exhibited worse olfactory function and decreased
trigeminal sensitivity than patients with PVOD.
Conclusions:
Olfactory and intranasal trigeminal systems are closely connected.
With regard to intranasal trigeminal ERP, patients with olfactory
dysfunction showed longer latency and lower amplitude, which
indicated decreased trigeminal sensitivity. Different etiology and
olfactory status also affect trigeminal sensitivity differently.
Keywords:
Olfactory dysfunction, T&T olfactometer, trigeminal
event-related potentials Acknowledgements: China Natural
Scientific Foundation under project No. 30973284, Capital Medical
Development Foundation under project No. 2007-1034.
#P44
POSTER SESSION II:
TRIGEMINAL SYSTEM; TASTE CNS;
NEUROIMAGING; OLFACTION CNS
Understanding the time course and quality of oral sensations
from over-the-counter analgesics
Samantha M Bennett
1,2
, John E Hayes
1,2
1
Pennsylvania State Univeristy/Department of Food Science
University Park, PA, USA,
2
Sensory Evaluation Center University
Park, PA, USA
The acceptability and palatability of children’s medications is an
ongoing problem for parents and medical professionals. rejection
of unpalatable medications hurts compliance with medical regimes
and can lead to harm of the child. unfortunately, many biologically
or pharmaceutically active compounds taste bitter and/or irritate the
mouth or throat. the irritation and bitterness of ibuprofen has been
studied previously, but it is not clear how the sensory properties of
other commonly used over-the-counter (otc) pain medications
compare. this is particularly important when considering
appropriate palatability improvement strategies, as techniques to
reduce bitterness and irritation may not be the same across
pharmaceutical agents whose sensations arise from physiologically
distinct systems. here, using a panel of minimally trained
participants (n=20), we show that the time course and qualitative
aspects of acetaminophen, naproxen, and ibuprofen differ, despite
the structural similarity of naproxen and ibuprofen. naproxen and
ibuprofen were rated as mostly irritating, with some bitterness,
where acetaminophen was mostly bitter with some irritation. none
of the compounds were rated as being significantly sour. this
42 | AChemS Abstracts 2012
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