TY  - JOUR
A1  - Röser, Claudia
A1  - Jordan, Nadine
A1  - Balfanz, Sabine
A1  - Baumann, Arnd
A1  - Walz, Bernd
A1  - Baumann, Otto
A1  - Blenau, Wolfgang
T1  - Molecular and pharmacological characterization of serotonin 5-HT2 alpha and 5-HT7 receptors in the salivary glands of the blowfly calliphora vicina
JF  - PLoS one
N2  - Secretion in blowfly (Calliphora vicina) salivary glands is stimulated by the biogenic amine serotonin (5-hydroxytryptamine, 5-HT), which activates both inositol 1,4,5-trisphosphate (InsP(3))/Ca2+ and cyclic adenosine 3',5'-monophosphate (cAMP) signalling pathways in the secretory cells. In order to characterize the signal-inducing 5-HT receptors, we cloned two cDNAs (Cv5-ht2 alpha, Cv5-ht7) that share high similarity with mammalian 5-HT2 and 5-HT7 receptor genes, respectively. RT-PCR demonstrated that both receptors are expressed in the salivary glands and brain. Stimulation of Cv5-ht2 alpha-transfected mammalian cells with 5-HT elevates cytosolic [Ca2+] in a dose-dependent manner (EC50 = 24 nM). In Cv5-ht7-transfected cells, 5-HT produces a dose-dependent increase in [cAMP](i) (EC50 = 4 nM). We studied the pharmacological profile for both receptors. Substances that appear to act as specific ligands of either Cv5-HT2 alpha or Cv5-HT7 in the heterologous expression system were also tested in intact blowfly salivary gland preparations. We observed that 5-methoxytryptamine (100 nM) activates only the Cv(5)-HT2 alpha receptor, 5-carboxamidotryptamine (300 nM) activates only the Cv5-HT7 receptor, and clozapine (1 mu M) antagonizes the effects of 5-HT via Cv5-HT7 in blowfly salivary glands, providing means for the selective activation of each of the two 5-HT receptor subtypes. This study represents the first comprehensive molecular and pharmacological characterization of two 5-HT receptors in the blowfly and permits the analysis of the physiological role of these receptors, even when co-expressed in cells, and of the modes of interaction between the Ca2+- and cAMP-signalling cascades. Citation: Roser C, Jordan N, Balfanz S, Baumann A, Walz B, et al. (2012) Molecular and Pharmacological Characterization of Serotonin 5-HT2a and 5-HT7 Receptors in the Salivary Glands of the Blowfly Calliphora vicina.
Y1  - 2012
U6  - https://doi.org/10.1371/journal.pone.0049459
SN  - 1932-6203
VL  - 7
IS  - 11
PB  - PLoS
CY  - San Fransisco
ER  - 
TY  - JOUR
A1  - Blankenburg, Stefanie
A1  - Balfanz, Sabine
A1  - Hayashi, Y.
A1  - Shigenobu, S.
A1  - Miura, T.
A1  - Baumann, Otto
A1  - Baumann, Arnd
A1  - Blenau, Wolfgang
T1  - Cockroach GABA(B) receptor subtypes: Molecular characterization, pharmacological properties and tissue distribution
JF  - Neuropharmacology
N2  - gamma-aminobutyric acid (GABA) is the predominant inhibitory neurotransmitter in the central nervous system (CNS). Its effects are mediated by either ionotropic GABA(A) receptors or metabotropic GABA(B) receptors. GABA(B) receptors regulate, via Gi/o, G-proteins, ion channels, and adenylyl cyclases. In humans, GABA(B) receptor subtypes are involved in the etiology of neurologic and psychiatric disorders. In arthropods, however, these members of the G-protein-coupled receptor family are only inadequately characterized. Interestingly, physiological data have revealed important functions of GABA(B) receptors in the American cockroach, Periplaneta americana. We have cloned cDNAs coding for putative GABA(B) receptor subtypes 1 and 2 of P. americana (PeaGB1 and PeaGB2). When both receptor proteins are co-expressed in mammalian cells, activation of the receptor heteromer with GABA leads to a dose-dependent decrease in cAMP production. The pharmacological profile differs from that of mammalian and Drosophila GABA(B) receptors. Western blot analyses with polyclonal antibodies have revealed the expression of PeaGB1 and PeaGB2 in the CNS of the American cockroach. In addition to the widespread distribution in the brain, PeaGB1 is expressed in salivary glands and male accessory glands. Notably, PeaGB1-like immunoreactivity has been detected in the GABAergic salivary neuron 2, suggesting that GABA(B) receptors act as autoreceptors in this neuron.
KW  - GABA(B) receptor
KW  - G-protein-coupled receptor
KW  - Periplaneta americana
KW  - Central nervous system
KW  - Adenylyl cyclase
KW  - Salivary gland
Y1  - 2015
U6  - https://doi.org/10.1016/j.neuropharm.2014.08.022
SN  - 0028-3908
SN  - 1873-7064
VL  - 88
SP  - 134
EP  - 144
PB  - Elsevier
CY  - Oxford
ER  -