Myoelectrogram, strain gauge force transducer or manometry has been commonly used to record contractile activity of the gastrointestinal (GI) tract in small animals, but protecting the lead wires and tubes is troublesome when conducting experiments. To solve this problem, we have developed a new telementric recorder which can be implanted in the abdominal cavity of a small animal. The telemeter is a cylinder (Φ10×35 mm) with a strain gauge force transducer (4×3 mm) connected by fine lead wires. The telemeter includes a battery and amplification, transmission and power supply circuit to the transducer. The battery has a 1, 500 hr life and is designed to be turned on and off from outside the body by means of a magnetic switch. The device weighs 4 g and is waterproofed with silicon.
Five male Wister rats weighing 300-400 g were used. Under general anesthesic, the force transducer was sutured onto the serosa in the gastric antrum, and the telemeter was fixed in the corner of the peritoneal cavity. During measurement, the rats were housed in individual cages under unrestrained conditions and the cage was placed on the receiver.
Gastric motility could be continuously recorded for up to 60 days, although body movements sometimes affected the recordings slightly due to adhesion. There was no noticeable trouble related to the device implanted in the abdominal cavity. Gastric motility recorded with this telemeter was identical wiht that measured by other devices, and consisted of two different patterns, the fasted and fed patterns divided into two phases, as reported previously. In the fasted state, cyclic occurrence of intense contractions was observed, and regular phasic contractions were observed in the fed state. Bethanechol induced strong contractions and atropine inhibited contractile activity.
The newly developed telemeter is a useful and reliable device to use in measuring GI motility in small animals.

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This study is to determine which part or the upper urinary tract, ueter or pelvis causes more significant delay in the pressure wave-front propagation from the bladder to the pelvis when a reverse flow of the urine occurs.
A sudden rise in the intravesical pressure of the dog was produced by stimulating the vesical branches of pelvic nerve with a train of electrical impulses whith 10 Hz for 60 sec. In order to eliminate the physiological mechanism that prevens a reverse flow of the urine at the uretero-vesical junction, a 3 cm vinyl tube was inserted into the ureteral orifice in all experiments except the cases with ureteral substitution (group II and III). Changes in intrapelvic pressure were measured from 7 dogs without substitution of either ureter or pelvis, and used as the control responses for comparison with those recorded from the dogs with artificial ureter and/or pelvis. Artificial ureter was made by a vinyl tube of 25 cm, whereas artificial pelvis was made by a 3 ml plastic chamber. Twenty-eight dogs were divided into 3 groups. Group I consisted of 7 dogs whose pelvises were replaced by artificial ones. Group II included 8 dogs whose ureters were substituted by artificial ones, and group III consisted of 6 dogs whose both ureter and pelvis were replaced by artificial ones.
Results obtained were as follows; (1) There was no significant difference between the maximum intravesical pressure and the maximum intrapelvic pressure recorded from every dog in all groups.(2) The onset time of intrapelvic response recorded from the control dog showed a delay from that of intravesical response by 2.05±1.03 sec.(3) The onset time of intrapelvic response recorded from group I, II and III were 0.51±0.94 sec., 1.95±1.10 sec., 0.10±0.25 sec., respectively.(4) Statistically significant difference in the delay of response was observed only between the responses recorded from the control or group II and the responses recorded from group I or III.
The above results suggested that the major site causing a significant delay in the pressure wave-front propagation from the bladder to the pelvis is the pelvic area including caryx, but not the ureteral region, when a reverse flow of the urine occurs.

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To evaluate the functioning and effectiveness of a 20-cm reversed jejunal segment after 75-80% massive small bowel resection (MSBR), and whether migrating polarity changes or not, we continuously measured the postoperative bowel motility (using bipolar electrodes and/or contractile strain gage force transducers) in interdigestive and postprandial conscious dogs in short-(2-5 weeks) and long-term (6-10 months) after surgery.
The fasting migrating myoelectric (or motor) complex (MMC) arising from the duodenum was often interrupted at the jejunum above the proximal anastomosis and did not migrate smoothly to the reversed segment or terminal ileum. In addition, brief small discordant contractions were frequent in the jejunum above the proximal anastomosis and the proximal part of the reversed segment. The duodenal MMC_s predominantly propagated to the ileum through the inherent anatomic continuity of the bowel. These findings of the MMC propagation pattern are very similar in short- and in long-term after surgery. The duration of the postprandial period without duodenal MMC activity was markedly longer in short-term, but shorter in long-term (both were significantly longer than in controls).
Marked dilatation of the jejunum and reversed jejunal segment was noted across the proximal anastomosis.
These results suggest that the transit time and passage of intestinal contents can be delayed and stagnated for at least 10 months after MSBR with a 20-cm reversed jejunal segment.
Although, reports on the polarity of peristalsis in the reversed segment in long-term followup have been contradictory in both experimental and clinical studies, this results support the conclusion that the reversed jejunal segment maintains its inherent propagative polarity and pattern over a long postoperative period.

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