title: Regulation of transepithelial ion transport in the rat late distal colon by the sympathetic nervous system.
abstract: The colorectum (late distal colon) is innervated by the sympathetic nervous system, and many colorectal diseases are related to disorders of the sympathetic nervous system. The sympathetic regulation of colorectal ion transport is rarely reported. The present study aims to investigate the effect of norepinephrine (NE) in the normal and catecholamine-depleted condition to clarify the regulation of the sympathetic adrenergic system in ion transport in the rat colorectum. NE-induced ion transport in the rats colorectum was measured by short-circuit current (I(sc)) recording; the expression of beta-adrenoceptors and NE transporter (NET) were quantified by real-time PCR, and western blotting. When the endogenous catecholamine was depleted by reserpine, the baseline I(sc) in the colorectum was increased significantly comparing to controls. NE evoked downward deltaI(sc) in colorectum of treated rats was 1.8-fold of controls. The expression of beta(2)-adrenoceptor protein in the colorectal mucosa was greater than the control, though the mRNA level was reduced. However, NET expression was significantly lower in catecholamine-depleted rats compared to the controls. In conclusion, the sympathetic nervous system plays an important role in regulating basal ion transport in the colorectum. Disorders of sympathetic neurotransmitters result in abnormal ion transport, beta-adrenoceptor and NET are involved in the process.
authors.affiliation: Artificial Liver Center, Beijing Youan Hospital, Capital Medical University, Beijing, China, Key Laboratory for Medical Tissue Regeneration of Henan Province, School of Basic Medical Sciences, Xinxiang Medical University, Xinxiang, Henan, China. zhu_jx@ccmu.edu.cn or/and duan2517@163.com.
authors.forename: X
authors.initials: X
authors.lastname: Zhang
authors.forename: Y
authors.initials: Y
authors.lastname: Li
authors.forename: X
authors.initials: X
authors.lastname: Zhang
authors.forename: Z
authors.initials: Z
authors.lastname: Duan
authors.forename: J
authors.initials: J
authors.lastname: Zhu
mesh_terms: D018759:Adrenergic Uptake Inhibitors / Q000494:pharmacology; D000818:Animals; D003106:Colon / Q000294:innervation* / Q000378:metabolism*; D004847:Epithelial Cells / Q000378:metabolism*; D066298:In Vitro Techniques; D007413:Intestinal Mucosa / Q000294:innervation* / Q000378:metabolism*; D017136:Ion Transport; D008297:Male; D008564:Membrane Potentials; D009638:Norepinephrine / Q000378:metabolism / Q000494:pharmacology; D050484:Norepinephrine Plasma Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D017207:Rats, Sprague-Dawley; D018343:Receptors, Adrenergic, beta-2 / Q000235:genetics / Q000378:metabolism; D013564:Sympathetic Nervous System / Q000187:drug effects / Q000502:physiology*; D013566:Sympathomimetics / Q000494:pharmacology; D013997:Time Factors
chemical_list: D018759:Adrenergic Uptake Inhibitors; D050484:Norepinephrine Plasma Membrane Transport Proteins; D012333:RNA, Messenger; D018343:Receptors, Adrenergic, beta-2; C493226:Slc6a2 protein, rat; D013566:Sympathomimetics; D009638:Norepinephrine