正常的胃功能受到神经激素、肌电和胃可收缩性之间复杂的相互作用的调节。[13]Patrick A, Epstein O. Review article: gastroparesis. Aliment Pharmacol Ther. 2008;27:724-740.http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2036.2008.03637.x/fullhttp://www.ncbi.nlm.nih.gov/pubmed/18248660?tool=bestpractice.com容纳咽下的食物、混合食物以及将营养物排空到小肠是胃最重要的运动功能。[14]Koch KL. Diabetic gastropathy: gastric neuromuscular dysfunction in diabetes mellitus: a review of symptoms, pathophysiology, and treatment. Dig Dis Sci. 1999;44:1061-1075.http://www.ncbi.nlm.nih.gov/pubmed/10389675?tool=bestpractice.com
胃的收缩性被认为由Cajal间质细胞 (interstitial cells of Cajal, ICC) 产生的胃慢波控制,大约每分钟3次。[15]Hinder RA, Kelly KA. Human gastric pacesetter potential. Site of origin, spread, and response to gastric transection and proximal gastric vagotomy. Am J Surg. 1977;133:29-33.http://www.ncbi.nlm.nih.gov/pubmed/835775?tool=bestpractice.com由Cajal间质细胞产生的电活动开始于胃底与胃体连接处,呈圆周样扩展,并且逐渐向远侧推向幽门。Cajal间质细胞与胃平滑肌细胞相关联,无论何时胃受到餐后刺激,机电耦合就会产生一个动作电位,从而产生胃收缩,最终导致胃排空。这种应答也受到肠多肽(例如胃动素、缩胆囊素)以及迷走神经的调节。任何扰乱时相或正常胃收缩强度的过程均会导致胃轻瘫。
糖尿病胃轻瘫的发病机理已经得到充分研究。胃排空延迟被认为是糖尿病自主神经病变影响了迷走神经的表现,导致胃窦收缩频率下降,胃部张力降低,缺乏胃窦和十二指肠协调性,胃窦运动减弱以及幽门痉挛,从而导致固体食物排空缓慢。[16]Soykan I, Sivri B, Sarosiek I, et al. Demography, clinical characteristics, psychological and abuse profiles, treatment, and long-term follow-up of patients with gastroparesis. Dig Dis Sci. 1998;43:2398-2404.http://www.ncbi.nlm.nih.gov/pubmed/9824125?tool=bestpractice.com[17]Camilleri M, Brown ML, Malagelada JR. Relationship between impaired gastric emptying and abnormal gastrointestinal motility. Gastroenterology. 1986;91:94-99.http://www.ncbi.nlm.nih.gov/pubmed/3710086?tool=bestpractice.com[18]Houghton LA, Read NW, Heddle R, et al. Relationship of the motor activity of the antrum, pylorus, and duodenum to gastric emptying of a solid-liquid mixed meal. Gastroenterology. 1988;94:1285-1291.http://www.ncbi.nlm.nih.gov/pubmed/3360256?tool=bestpractice.com[19]Mearin F, Camilleri M, Malagelada JR. Pyloric dysfunction in diabetics with recurrent nausea and vomiting. Gastroenterology. 1986;90:1919-1925.http://www.ncbi.nlm.nih.gov/pubmed/3699409?tool=bestpractice.com一些证据表明,糖尿病患者的Cajal间质细胞网络的破坏、[20]Forster J, Damjanov I, Lin Z, et al. Absence of the interstitial cells of Cajal in patients with gastroparesis and correlation with clinical findings. J Gastrointest Surg. 2005;9:102-108.http://www.ncbi.nlm.nih.gov/pubmed/15623450?tool=bestpractice.com[21]Zarate N, Mearin F, Wang XY, et al. Severe idiopathic gastroparesis due to neuronal and interstitial cells of Cajal degeneration: pathological findings and management. Gut. 2003;52:966-970.http://www.ncbi.nlm.nih.gov/pubmed/12801952?tool=bestpractice.com直接的血糖毒性以及受损的餐后胃肠激素释放使糖尿病患者易患胃轻瘫。[22]Hasler WL, Soudah HC, Dulai G, et al. Mediation of hyperglycemia-evoked gastric slow-wave dysrhythmias by endogenous prostaglandins. Gastroenterology. 1995;108:727-736.http://www.ncbi.nlm.nih.gov/pubmed/7875475?tool=bestpractice.com[23]Fraser RJ, Horowitz M, Maddox AF, et al. Hyperglycaemia slows gastric emptying in type 1 (insulin-dependent) diabetes mellitus. Diabetologia. 1990;33:675-680.http://www.ncbi.nlm.nih.gov/pubmed/2076799?tool=bestpractice.com
胃底折叠术等手术操作造成的无意的迷走神经损伤、或者多发性硬化等疾病过程中造成的迷走神经核脱髓鞘等情况,都会导致胃轻瘫,[24]Hunter RJ, Metz DC, Morris JB, et al. Gastroparesis: a potential pitfall of laparoscopic Nissen fundoplication. Am J Gastroenterol. 1996;91:2617-2618.http://www.ncbi.nlm.nih.gov/pubmed/8947000?tool=bestpractice.com从而强调了迷走神经在正常胃排空中的作用。[10]Raghav S, Kipp D, Watson J, et al. Gastroparesis with multiple sclerosis. Mult Scler. 2006;12:243-244.http://www.ncbi.nlm.nih.gov/pubmed/16629430?tool=bestpractice.com[25]Reddymasu SC, Bonino J, McCallum RW. Gastroparesis secondary to a demyelinating disease: a case series. BMC Gastroenterol. 2007;7:3.http://www.ncbi.nlm.nih.gov/pubmed/17266755?tool=bestpractice.com