Digestive Diseases and Sciences, Vol. 49, No. 5 (May 2004), pp. 757–762 ( C  2004) Gastric Emptying and Gastrointestinal Transit of Liquid in Awake Rats Is Delayed After Acute Myocardial Infarction FL ´ AVIO DUARTE CAMURC ¸ A, MD, D ´ ARIO AUGUSTO FERREIRA DE QUEIROZ, PAULO ROBERTO LACERDA LEAL, MD, CLEON ´ ISIO LEITE RODRIGUES, MD, FRANCISCO DE ASSIS AQUINO GONDIM, MD, PhD, JOS ´ E RONALDO VASCONCELOS DA GRAC ¸ A, MD, MSc, FRANCISCO H ´ ELIO ROLA, MD, PhD, MIGUEL ANGELO NOBRE E SOUZA, MD, PhD, and ARMENIO AGUIAR DOS SANTOS, MD, PhD The outcome of acute myocardial infarction (AMI) on gastrointestinal motor behavior was assessed in awake rats. Under anesthesia, they were submitted to thoracotomy followed or not by occlusion of the left coronary artery. Next day, they were gavage fed (1.5 ml) with phenol red in 5% glucose solution and sacrificed 10, 20, or 30 min later. Each subset consisted of 7 to 19 animals. Dye recovery in the stomach, proximal, mid, and distal small intestine was obtained by spectrophotometry. Infarcted left ventricle plus septum area was about 48.9 ± 2.8, 55.1 ± 6.7, and 54.1 ± 8.1% (respectively, for 10-, 20-, and 30-min subsets). AMI increased gastric dye retention by 25.5, 51.3, and 65.1% (respectively, for 10-, 20-, and 30-min subsets), while it decreased mid small intestine retention at 30 min (45.3%) as well as distal retention at 10 min (90.5%) and 20 min (90%). A positive correlation (r S = 0.64) was found between infarcted area and gastric retention values at 10 min. AMI also increased ( P < 0.05) central venous pressure values in all subsets (3.8 ± 0.2 vs. −2.1 ± 1.5, 1.4 ± 0.1 vs. 0.5 ± 0.2, and 1.6 ± 0.4 vs. −0.2 ± 0.3 cm H 2 O), while it decreased ( P < 0.05) mean arterial pressure (95.0 ± 2.6 vs. 110.0 ± 3.9 and 106.0 ± 2.0 vs. 113.0 ± 3.0 mm Hg, respectively, at 10 and 30 min), and increased ( P < 0.05) the 10-min heart rate values (429.6 ± 11.3 vs. 374.0 ± 19.8 bpm). Omeprazole pretreatment did not alter this phenomenon. In another group of rats, cardiac chemoreflex stimulation by i.v. phenylbiguanide increased gastric dye retention by 51.1%. In conclusion, AMI delays the gastric emptying and gastrointestinal transit of liquid in awake rats. KEY WORDS: gastric emptying; gastrointestinal motility, myocardial infarction; phenylbiguanide; rats. Acute myocardial infarction (AMI) is the leading cause of congestive heart failure, cardiac arrhythmia, and sudden death in adults. Upper digestive symptoms like bloating, epigastric pain, nausea, and vomiting are frequent findings Manuscript received September 30, 2003; accepted January 10, 2004. From the Department of Physiology and Pharmacology, Faculty of Medicine, Federal University of Cear´ a, Fortaleza, Cear´ a, Brazil. Address for reprint requests: Dr. Armenio Aguiar dos Santos, Depart- mento de Fisiologia e Farmacologia, Faculdade de Medicina, Universi- dade Federal do Cear´ a, Rua Coronel Nunes de Melo, 1127 Caixa Postal 3157, 60.430-270 Fortaleza, CE, Brasil; meno@ufc.br. in AMI (1–3). However, little is known about the phys- iopathological mechanisms involved in such phenomena (4). In this regard, it is well known that myocardial ischemia stimulates cardiac receptors that may trigger the Bezold– Jarisch reflex, characterized by tachypnea, bradycardia, and hypotension (5). In fact, Johannsen and co-workers (1981) observed that cardiac chemoreceptors stimulation by veratridine i.v. injection to anesthetized dogs also in- duced gastric dilatation (6). Relating to this subject, we have also shown a functional relationship between the gut Digestive Diseases and Sciences, Vol. 49, No. 5 (May 2004) 757 0163-2116/04/0500-0757/0 C  2004 Plenum Publishing Corporation