Gastric Motility In Rats Research Articles

Effects of caerulein on the gastric motility of rats.

The effects of caerulein on gastric motility in urethane-anesthetized rats were studied. Caerulein administered into the lateral cerebral ventricle (i.c.v.) and jugular vein (i.v.) caused predominantly an inhibitory effect on gastric motility but sometimes an excitatory or a biphasic effect. The inhibitory response was reduced after vagotomy and/or splanchnicotomy, or after guanethidine. The remaining inhibitory response was abolished by tetrodotoxin, but was resistant to atropine and guanethidine. The excitatory response was abolished by atropine. Discharges of the gastric branch of the vagus nerve were decreased by i.v. injection of caerulein but increased by i.c.v. injection, whereas those of the splanchnic nerve were increased by both i.v. and i.c.v. injection. These results suggest that caerulein causes an inhibition of gastric motility by centrally stimulating vagal non-adrenergic inhibitory nerves and splanchnic adrenergic nerves and inhibiting vagal cholinergic nerves, and by peripherally stimulating non-adrenergic inhibitory neurons of the myenteric plexus. This peptide causes an excitation by stimulating cholinergic neurons of the myenteric plexus.

The effect of cecal volume change on gastric motility in rats.

The effect of a change in cecal volume on gastric motility was studied in 24 h fasted rats anesthetized with urethane (0.8 g/kg, i.p.). A cecal volume increase from 1 to 10 ml (in 1 ml steps) produced a decrease in the basal tone of the stomach. The maximal inhibitory response was produced with an 8 to 10-ml increase in cecal volume. The gastric inhibitory response continued as long as the increased cecal volume was maintained. It was abolished by a combination of a splanchnicotomy and vagotomy, or only a splanchnicotomy in a few cases. The inhibition of gastric motility by increasing the cecal volume also occurred after severance of dorsal roots between T8 and L4 and gastric branches of vagus nerves. It is suggested that an increase in cecal volume induces gastric relaxation mainly via the splanchnico-splanchnic pathway and partly via the vago-vagal and vago-splanchnic pathways. Therefore, retardation in transit of the gastric contents in germ free rats having an enlarged cecum may be attributed to an enhancement of the ceco-gastric inhibitory reflex. The ceco-gastric inhibitory response mediated by the splanchnic pathway was abolished by guanethidine (3-5 mg/kg, i.v.), but the response mediated by the vagal pathway was resistant to guanethidine as well as to atropine (0.2 mg/kg, i.v.). This result indicates that splanchnic postganglionic efferents are adrenergic, while vagal postganglionic efferents are non-adrenergic and non-cholinergic.

Effects of Locust Bean Gum on Glucose Tolerance, Sugar Digestion, and Gastric Motility in Rats

Effects of selected undigestible gel-forming complex carbohydrates, including locust bean gum, guar gum, and pectin, on glucose tolerance and food motility were studied in rats. Addition of 2.5% of guar gum or locust bean gum to an oral glucose tolerance test solution significantly altered the postprandial serum glucose response. Although all three complex carbohydrates tested did not reduce the initial rise in serum glucose, locust bean gum and guar gun significantly reduced its subsequent rebound hypoglycemia. Further tests with locust bean gum showed that these effects were dependent on the concentration of the gum added to the test solution or diet. Addition of locust bean gum to test diets reduced the rate of gastric emptying and thus slowed down the passage of food from the stomach into the upper small intestine. The study suggests that addition of locust bean gum to the diet can flatten the post-prandial serum glucose curve by slowing the rate of food passage from the stomach into the small intestine. It is probable that locust bean gum and other similar materials may be useful as an adjunct dietary treatment of diabetes mellitus in humans.locust bean gum fiber gastric emptying serum glucose

Relations between various fiber groups of vagal and splanchnic nerves and gastric motility in rats

Gastric motility changes evoked in rats by electrical stimulation of centrally transected vagal and splanchnic B and C fibers were investigated. Gastric motility was slightly facilitated by repetitive stimulation of vagal B fibers and was greatly facilitated by similar stimulation of the C fibers. In addition, vagal C fiber stimulation evoked a transient, initial inhibition of motility. Splanchnic C fiber stimulation inhibited gastric motility, but the B fiber contribution to inhibition was much greater.

Effect of prostaglandin E1 on rat gastric motility and cyclic nucleotide content

Administration of exogenous prostaglandin E1 resulted in an increase in contractility of rat fundic muscle measured in vivo; a significant decrease in fundic tissue levels of cyclic- adenosine monophosphate and a significant increase in cyclic-guanosine monophosphate.