BACKGROUND The majority of patients with cholinergic urticaria presents with strong hypersensitivity to autologous sweat. Patients with severe cholinergic urticaria are frequently resistant to H(1) antagonists which are used in conventional therapies for various types of urticaria. It has been reported that desensitization using partially purified sweat antigen was effective in a patient with c...

Metabotropic glutamate receptors (mGluRs) coupled to phosphoinositide hydrolysis desensitize in response to prolonged or repeated agonist exposure, and evidence suggests that this involves activation of protein kinase C (PKC). The present studies were undertaken to determine if cloned mGluR5 undergoes similar PKC-mediated desensitization and to investigate the molecular mechanism underlying PKC...

Accompanied by the growing clinical applications of immunotherapy in the treatment of cancer patients, development of novel therapeutic approaches to reverse the immune-suppressive environment in cancer patients is eagerly anticipated, because the success of cancer immunotherapy is currently limited by immune-suppressive effects in tumor-bearing hosts. Interleukin (IL)-6, a pleotropic proinflam...

The effect of specific competitive inhibitors of aminoacyl-tRNA synthetase on thyrotropin (TSH) desensitization in human thyroid cell monolayers was examined. Thyroid cells were preincubated with o r without 60 milliunits/ml of TSH for 16 h at 37 “C in histidinefree medium supplemented with either 2 m~ histidinol or 2 mM histidine (control medium). All cells were then exposed to TSH for 30 min ...

Recent studies have demonstrated that in vivo administration of 1-deamino-8-D-arginine-vasopressin, an analog of arginine-8-vasopressin, induces homologous desensitization to vasopressin in the thick ascending limb of the loop of Henle. Desensitization has been documented by a decreased physiological response to vasopressin in vivo and by a reduced cAMP accumulation in the cortical thick ascend...

Mu-opioid receptors (MORs) activate G-protein coupled inwardly rectifying potassium (GIRK) channels. The peptide agonist [D-Ala(2), NMe-Phe(4), Gly(5)-ol]enkephalin (DAMGO), but not the alkaloid morphine (MS), leads to acute desensitization of this response. Furthermore, DAMGO, as opposed to MS, triggers rapid internalization of MORs. Given this dichotomy, we probed the relationship between rec...

Ionotropic glutamate receptors from the AMPA and kainate subfamilies share many functional and structural features, but it is unclear whether this similarity extends to the molecular mechanisms underlying receptor desensitization. The current model for desensitization in AMPA receptors involves the rearrangement of dimers formed between subunit agonist binding domains. Key evidence for this has...

It is hypothesized that desensitization of neuronal nicotinic acetylcholine receptors (nAChRs) induced by chronic exposure to nicotine initiates upregulation of nAChR number. To test this hypothesis directly, oocytes expressing alpha4beta2 receptors were chronically incubated (24-48 hr) in nicotine, and the resulting changes in specific [3H]nicotine binding to surface receptors on intact oocyte...

P2X ion channels have been functionally characterized from a range of eukaryotes. Although these receptors can be broadly classified into fast and slow desensitizing, the molecular mechanisms underlying current desensitization are not fully understood. Here, we describe the characterization of a P2X receptor from the cattle tick Boophilus microplus (BmP2X) displaying extremely slow current kine...