title: Impairments of the primary afferent nerves in a rat model of diabetic visceral hyposensitivity.
abstract: BACKGROUND
  Diabetic neuropathy in visceral organs such as the gastrointestinal (GI) tract is still poorly understood, despite that GI symptoms are among the most common diabetic complications. The present study was designed to explore the changes in visceral sensitivity and the underlying functional and morphological deficits of the sensory nerves in short-term diabetic rats. Here, we compared the colorectal distension (CRD)-induced visceromotor response (VMR, an index of visceral pain) in vivo, the mechanosensitivity of colonic afferents ex vivo as well as the expression of protein gene product (PGP) 9.5 and calcitonin gene-related peptide (CGRP) in colon between diabetic (3-6 weeks after streptozotocin injection) and control (age-matched vehicle injection) rats.
  
  
  RESULTS
  VMR was markedly decreased in the diabetic compared to the control rats. There was a significant decrease in multiunit pelvic afferent nerve responses to ramp distension of the ex vivo colon and single unit analysis indicated that an impaired mechanosensitivity of low-threshold and wide dynamic range fibers may underlie the afferent hyposensitivity in the diabetic colon. Fewer PGP 9.5- or CGRP-immunoreactive fibers and lower protein level of PGP 9.5 were found in the colon of diabetic rats.
  
  
  CONCLUSIONS
  These observations revealed the distinctive feature of colonic neuropathy in short-term diabetic rats that is characterized by a diminished sensory innervation and a blunted mechanosensitivity of the remnant sensory nerves.
authors.affiliation: Hongqiao International Institute of Medicine, Shanghai Tongren Hospital, Shanghai Jiaotong University School of Medicine, 1111 Xianxia Road, Shanghai, 200050, China. dongli@shsmu.edu.cn.|Department of Physiology, Faculty of Basic Medicine, Shanghai Jiaotong University School of Medicine, 280 South Chongqing Road, Shanghai, 200025, China. dongli@shsmu.edu.cn.
authors.forename: Li
authors.initials: L
authors.lastname: Dong
authors.affiliation: Department of Pathology, Shanghai Ninth People's Hospital, Shanghai Jiaotong University School of Medicine, 659 Zhizhaoju Road, Shanghai, 200011, China. 15216606165@163.com.
authors.forename: Xizi
authors.initials: X
authors.lastname: Liang
authors.affiliation: Hongqiao International Institute of Medicine, Shanghai Tongren Hospital, Shanghai Jiaotong University School of Medicine, 1111 Xianxia Road, Shanghai, 200050, China. 13661779180@163.com.|Department of Physiology, Faculty of Basic Medicine, Shanghai Jiaotong University School of Medicine, 280 South Chongqing Road, Shanghai, 200025, China. 13661779180@163.com.
authors.forename: Biying
authors.initials: B
authors.lastname: Sun
authors.affiliation: Department of Physiology, Faculty of Basic Medicine, Shanghai Jiaotong University School of Medicine, 280 South Chongqing Road, Shanghai, 200025, China. xiaoweid712@163.com.
authors.forename: Xiaowei
authors.initials: X
authors.lastname: Ding
authors.affiliation: Department of Pathology, Shanghai Ninth People's Hospital, Shanghai Jiaotong University School of Medicine, 659 Zhizhaoju Road, Shanghai, 200011, China. hxhan2004@hotmail.com.
authors.forename: Hongxiu
authors.initials: H
authors.lastname: Han
authors.affiliation: Hongqiao International Institute of Medicine, Shanghai Tongren Hospital, Shanghai Jiaotong University School of Medicine, 1111 Xianxia Road, Shanghai, 200050, China. ghzhang2009@shsmu.edu.cn.|Department of Physiology, Faculty of Basic Medicine, Shanghai Jiaotong University School of Medicine, 280 South Chongqing Road, Shanghai, 200025, China. ghzhang2009@shsmu.edu.cn.
authors.forename: Guohua
authors.initials: G
authors.lastname: Zhang
authors.affiliation: Hongqiao International Institute of Medicine, Shanghai Tongren Hospital, Shanghai Jiaotong University School of Medicine, 1111 Xianxia Road, Shanghai, 200050, China. weifangrong@shsmu.edu.cn.|Department of Physiology, Faculty of Basic Medicine, Shanghai Jiaotong University School of Medicine, 280 South Chongqing Road, Shanghai, 200025, China. weifangrong@shsmu.edu.cn.
authors.forename: Weifang
authors.initials: W
authors.lastname: Rong
mesh_terms: D000818:Animals; D015740:Calcitonin Gene-Related Peptide / Q000235:genetics; D003106:Colon / Q000294:innervation / Q000503:physiopathology; D003921:Diabetes Mellitus, Experimental / Q000473:pathology* / Q000503:physiopathology; D005786:Gene Expression Regulation; D008297:Male; D009475:Neurons, Afferent / Q000473:pathology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D043222:Ubiquitin Thiolesterase / Q000235:genetics; D014781:Viscera / Q000503:physiopathology
chemical_list: C489034:UCHL1 protein, rat; D043222:Ubiquitin Thiolesterase; D015740:Calcitonin Gene-Related Peptide