Protocol for chronic implantation of patch electrodes on the gastric muscle wall of the rat v1

Electrical stimulation is a potential therapy for gastric disorders. Here we describe our surgical procedure for the implantation of patch electrodes on the muscle wall of the stomach of both male and female rats for use in chronic studies looking at the long-term effects of stimulation on physiology and behavior. The surgery is well tolerated by the subjects as rats return to pre-surgical body weight and normal solid chow intake within 7 to 10 days post-surgery. In our hands, rats implanted using the methods described below have been continuously run in feeding and motility experiments for 8 to 12 weeks with minimal to no loss of subjects. When failure does occur, it is typically a result of back mount failure at the site of attachment of the overhead tether to the back mount.

Endokinin A/B stimulates rat gastric motility through myogenic NK1 receptors located in the fundus

Endokinin A/B (EKA/B), the common C-terminal decapeptide in endokinins A and B, is a preferred ligand of the NK1 receptor and regulates pain and itch. The study focused on the effects of EKA/B on rat gastric motility in vivo and in vitro. Gastric emptying was measured to evaluate gastric motility in vivo. Intragastric pressure and the contraction of gastric muscle strips were measured to evaluate gastric motility in vitro. Moreover, various neural blocking agents and neurokinin receptor antagonists were applied to explore the mechanisms. TAC4 and TACR1 mRNAs were expressed throughout rat stomach. EKA/B promoted gastric emptying by intraperitoneal injection in vivo. Correspondingly, EKA/B also increased intragastric pressure in vitro. Additionally, EKA/B contracted the gastric muscle strips from the fundus but not from the corpus or antrum. Further studies revealed that the contraction induced by EKA/B on muscle strips from the fundus could be significantly reduced by NK1 receptor antagonist SR140333 but not by NK2 receptor antagonist, NK3 receptor antagonist, or the neural blocking agents used. Our results suggested that EKA/B might stimulate gastric motility mainly through the direct activation of myogenic NK1 receptors located in the fundus.

POSTERIOR BELLY OF DI-GASTRIC MUSCLE – THE LANDMARK TO IDENTIFY FACIAL NERVE IN PAROTIDECTOMY

Objective:-To document Posterior belly of Di-gastric Muscle – The landmark to identify Facial Nerve in Parotidectomy. Methods:- In this study, relationship between posterior belly of digastrics and facial nerve trunk recorded in 21 patients who undergone Parotidectomy in our Institute. Results:-In all patients, Facial Nerve trunk was identified above the posterior belly of Di-gastric muscle with range of 5 to 10 mm. Conclusion:-This study confirmed that posterior belly of Di-gastric muscle in the landmark in identification of Facial nerve trunk in Parotidectomy.

Complication of Early Banana Feeding in Neonates

Early introduction of banana in newborn babies is still practiced by many mothers from different areas throughout the country and gastric perforation due to phytobezoars are sttll a problem tn the country. During the years 1984 through 1991 at the Children and Maternity Hospital Harapan Kita jakarta, fifteen neonates were treated for gastric perforation among which 6 were due to banana bezoar, 6 were due to deject of the gastric muscle, 2 were due to necrotizing enterocolitis (NEC) and 1 was due to iatrogenic duodenal obstruction. Pathogenesis of gastric perforation due to phytobezoar and the macroscopic and histopathological appearance of the perforation and its differences with perforations due to other causes were discussed.

Contractile Protein Expression and Phosphorylation and Contractility of Gastric Smooth Muscles from Obese Patients and Patients with Obesity and Diabetes

Ingested food is received, mixed, and ground into chyme by distinct gastric motility patterns. Diabetes impairs gastric muscle function, but the mechanisms underlying diabetes-induced gastric muscle dysfunction are unknown. Here, we compared the expression and phosphorylation of Ca2+ sensitization and contractile proteins in human gastric muscles from obese nondiabetic and diabetic patients. We also compared the spontaneous phasic contractions and the contractile responses evoked by electrical field stimulation of cholinergic motor neurons. Fundus and antrum muscles were obtained from sleeve gastrectomies and were used in in vitro myobath contractile studies and for capillary electrophoresis and immunodetection of γ-actin, CPI-17, pT38-CPI-17, MYPT1, pT853-MYPT1, pT696-MYPT1, myosin light chain (MYL9), pS19-MYL9, myosin light chain kinase (MYLK), protein phosphatase-1δ (PP1δ), and Rho-associated kinase (ROCK2). In diabetic fundus muscles, MYLK, ROCK2, and PP1δ expression was unchanged; MYPT1 and CPI-17 expression was decreased; and the pT853/MYPT1 and pT38/CPI-17 ratios, but not the pT696/MYPT1 ratio, were increased. Although MYL9 expression was increased, the pS19/MYL9 ratio was unchanged in diabetic fundus muscles. In diabetic antrum muscles, MYLK and MYL9 expression was unchanged, but ROCK2, CPI-17, and PP1δ expression was decreased. The pT38/CPI-17 ratio was unchanged, while the pS19/MYL9, pT853/MYPT1, and pT696/MYPT1 ratios were decreased, consistent with the reduced ROCK2 expression. The frequencies of spontaneous phasic contractions from nondiabetic and diabetic gastric fundus and antrum muscles did not significantly differ from each other, regardless of age, sex, or diabetic status. The fold increases in the contractions of diabetic fundus and antrum muscles in response to increased frequencies of electrical field stimulation were significantly lower compared to nondiabetic fundus and antrum muscles. The altered contractile responses and the protein expression and phosphorylation in gastric muscles of obese patients with diabetes illustrate the importance of understanding how smooth muscle Ca2+ sensitization mechanisms contribute to gastric motility.

Electrogastrography in Delayed Gastric Emptying

Disorders of gastric motility are generally manifested by an abnormal rate of gastric emptying. The emptying process of the stomach is very complex, and knowledge is limited to the observation that gastric emptying rate is a highly variable phenomenon, and that delayed gastric emptying is frequently the case. The advances in the knowledge of the physiology of gastric muscle and enteric nerves, and the recognition of the patterns of organization of smooth muscle contractions gave a new input to the study of gastric motility. The gastric emptying can be monitored in various ways, such as manometry, scintigraphy, or electrogastrography (EGG). Recently, EGG has received more attention. There is correlation between the EGG signal obtained from body surface electrodes and signals obtained directly from electrodes locates in the gastric muscle (serosal records). Some studies showed an association between EGG-findings and gastric motility disorders, and indicate that EGG is a reliable, non-invasive, useful method to detect gastric myoelectric activity.