Using a radiopaque marker with radiography for evaluating colonic transit by geometric center in conscious rats: A novel method.

This study developed a new method using radiopaque markers under X-ray to measure rat colonic transit by geometric center repeatedly and/or over a time series in the same individually. Additionally, the utility of this method was shown by elucidating the innervation of the autonomic nerve on colonic transit in detail with a pharmacological technique in conscious rats. An in-dwelling silastic cannula was inserted into the cecum and the proximal part was moved through the abdominal wall, where it was fixed to the posterior neck skin. Twenty markers were administered from the cannula to the proximal colon with saline on the fifth day after surgery. The markers were observed with soft X-ray before required repeated short anesthesia. Experimentation 1: Rats were measured colonic transit twice over 2 days with no administration. Experimentation 2: Rats were administered saline on the first day and pharmacology on the second day intraperitoneally before measurement. Experimentation 1: The markers administrated from the cannula and transited from proximal colon to distal colon over a time series. It showed no significant difference in complication rates between 2 days. Experimentation 2: The colonic transit was increasingly accelerated by neostigmine and phentolamine but not propranolol. Significant changes in 1.0 mg/kg atropine were noted although no differences were found between control and 0.05 mg/kg atropine and between each other's. We have presented the method using radiopaque markers under X-ray with short anesthesia for evaluating the colonic transit. The methods could show rat colonic transit changes in detail with a pharmacological technique.

Effects of Moxibustion on Stress-Induced Delayed Gastric Emptying via Somatoautonomic Reflex in Rats.

Objective: Moxibustion (MOX) is used to treat a wide variety of disorders, including those with gastric symptoms. However, the exact mechanisms underlying the beneficial effects of MOX are unknown. The purpose of this study was to investigate if application of indirect MOX (iMOX) to ST 36 reduces restraint stress (RS)-induced alteration in gastric responses of conscious rats, and if a somatoautonomic reflex mediates gastric emptying (GE). Materials and Methods: One group of rats was fed solid food after 24 hours of fasting. Immediately after food ingestion. These rats were subjected to RS. Ninety minutes after feeding, the rats were euthanized, and their gastric contents were removed to calculate GE. iMOX had been performed at ST 36 bilaterally throughout the stress loading. To investigate if vagal-nerve activity was involved in mediating the stress-induced alterations of GE by iMOX, atropine was intraperitoneally administered to other rats just before initiating RS; bilateral truncal vagotomy had been performed on day 14 before GE measurement. Results: RS delayed GE significantly (42.9 ± 5.8%)in stressed rats, compared to nonstressed rats (68.7 ± 1.8%). iMOX at ST 36 reduced stress-induced inhibition of GE significantly (67.1 ± 2.4%). MOX-mediated reduction of GE disappeared upon atropine injection and vagotomy. Conclusions: RS-induced delayed GE may be ameliorated by iMOX at ST 36. Somatoautonomic, reflex-induced vagal-nerve activity helps mediate the stimulatory effects of iMOX on RS-induced delayed GE. As a complementary and alternative medicine, iMOX may also be advantageous for patients with gastric disorders, such as functional dyspepsia.

Effect of acupuncture on the haemodynamic system in men.

BACKGROUND: Acupuncture stimulation decreases heart rate (HR) through somato-autonomic reflexes. However, the mechanisms responsible for other cardiovascular changes induced by acupuncture, such as its effects on stroke volume (SV) and blood pressure (BP), remain obscure. OBJECTIVE: To evaluate continuously the comprehensive cardiovascular changes occurring during acupuncture. METHOD: 20 healthy men participated in the study. HR, SV and BP were measured in the supine position using electrocardiogram, transthoracic impedance cardiography and continuous non-invasive finger blood pressure, respectively. Manual acupuncture stimulation using a stainless steel needle was performed at LI10 for 60 s after resting periods of approximately 15 min. RESULTS: HR was reduced and SV increased, in parallel, during the period of acupuncture stimulation (P<0.01, respectively). Diastolic blood pressure (DBP) decreased in the 10 s period of acupuncture stimulation compared with the 120 s pre-stimulation period (P<0.01) and recovered close to the pre-stimulation reading instantly after the transient reduction. No change was observed in cardiac output (CO) derived from HR and SV. CONCLUSIONS: This study indicates that HR reduction during acupuncture does occur, as previous reports have indicated. SV increased during acupuncture stimulation in parallel with HR reduction and CO was maintained during these changes. Any reduction in DBP caused by acupuncture recovered to baseline, likely due to baroreflexes.