Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P41181 (collecting duct)
 5,183 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Carbamazepine (CBZ)-induced water intoxication occasionally limits its usefulness in refractory seizures and trigeminal neuralgia. Fluid restriction, CBZ dose reduction, or concomitant phenytoin therapy may be impractical or ineffective. Demeclocycline (7-chloro-6 demethyl tetracycline) (DMC) corrected the CBZ-induced water intoxication in a 51-year-old man with refractory complex partial seizures and a normal antidiuretic hormone (ADH) level. DMC inhibits ADH-sensitive adenylate cyclase activity in the renal collecting duct and may be useful in correcting the ADH-like or renal antidiuretic effect of CBZ.
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PMID:Perspective on carbamazepine-induced water intoxication: reversal by demeclocycline. 309 19

Binding of vasopressin to its type 2 receptor in renal collecting ducts induces cAMP signaling, transcription and translocation of aquaporin (AQP)2 water channels to the plasma membrane, and water reabsorption from the prourine. Demeclocycline is currently used to treat hyponatremia in patients with the syndrome of inappropriate antidiuretic hormone secretion (SIADH). Demeclocycline's mechanism of action, which is poorly understood, is studied here. In mouse cortical collecting duct (mpkCCD) cells, which exhibit deamino-8-D-arginine vasopressin (dDAVP)-dependent expression of endogenous AQP2, demeclocycline decreased AQP2 abundance and gene transcription but not its protein stability. Demeclocycline did not affect vasopressin type 2 receptor localization but decreased dDAVP-induced cAMP generation and the abundance of adenylate cyclase 3 and 5/6. The addition of exogenous cAMP partially corrected the demeclocycline effect. As in patients, demeclocycline increased urine volume, decreased urine osmolality, and reverted hyponatremia in an SIADH rat model. AQP2 and adenylate cyclase 5/6 abundances were reduced in the inner medulla but increased in the cortex and outer medulla, in the absence of any sign of toxicity. In conclusion, our in vitro and in vivo data indicate that demeclocycline mainly attenuates hyponatremia in SIADH by reducing adenylate cyclase 5/6 expression and, consequently, cAMP generation, AQP2 gene transcription, and AQP2 abundance in the renal inner medulla, coinciding with a reduced vasopressin escape response in other collecting duct segments.
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PMID:Demeclocycline attenuates hyponatremia by reducing aquaporin-2 expression in the renal inner medulla. 2415 96