Pressor effect on blood pressure and renal nerve activity elicited by electroacupuncture in intact and acute hemorrhage rats

The 2 Hz and 15 Hz electroacupuncture induced reverse effect on autonomic function in healthy adult using a heart rate variability analysis

The purpose of the present study was to investigate effect of electro-acupuncture (EA) at different frequencies on autonomic function. Twenty healthy adult volunteers were studied, and underwent 4 sessions of EA (sham, 2 Hz, 15 Hz, and 50 Hz). Sham, 2 Hz, 15 Hz, and 50 Hz EA was applied to the bilateral Leg Three Li (足三里 zú sān lǐ, ST-36) and Upper Great Hollow (上巨虛 shàng jù xū, ST-37) acupoints. The intensity of electrical stimulation was adjusted to obtain visible twitching of the anterior tibial muscle about 2.0-2.5 mA except sham without electrical stimulation. The components of heart rate variability (HRV) and blood pressure were measured before EA (BLP), EA (EAP), and post-EA periods (PEP). The results indicated that the natural logarithmic high frequency power (lnHF) of HRV was greater during PEP than during the BLP in the 2 Hz EA sessions. The natural logarithmic low frequency power (lnLF) of HRV was greater during the PEP than during the BLP in 15 Hz EA sessions, suggesting that 2 Hz EA apply to Leg Three Li (足三里 zú sān lǐ, ST-36) and Upper Great Hollow (上巨虛 shàng jù xū, ST-37) acupoints increased vagal activity, whereas 15 Hz EA increased sympathetic activity.

Acupuncture reduces crying in infants with infantile colic: a randomised, controlled, blind clinical study

OBJECTIVE

To investigate whether acupuncture reduces the duration and intensity of crying in infants with colic. Patients and methods 90 otherwise healthy infants, 2-8 weeks old, with infantile colic were randomised in this controlled blind study. 81 completed a structured programme consisting of six visits during 3 weeks to an acupuncture clinic in Sweden. Parents blinded to the allocation of their children met a blinded nurse. The infant was subsequently given to another nurse in a separate room, who handled all infants similarly except that infants allocated to receive acupuncture were given minimal, standardised acupuncture for 2 s in LI4.

RESULTS

There was a difference (p=0.034) favouring the acupuncture group in the time which passed from inclusion until the infant no longer met the criteria for colic. The duration of fussing was lower in the acupuncture group the first (74 vs 129 min; p=0.029) and second week (71 vs 102 min; p=0.047) as well as the duration of colicky crying in the second intervention week (9 vs 13 min; p=0.046) was lower in the acupuncture group. The total duration of fussing, crying and colicky crying (TC) was lower in the acupuncture group during the first (193 vs 225 min; p=0.025) and the second intervention week (164 vs 188 min; p=0.016). The relative difference from baseline throughout the intervention weeks showed differences between groups for fussing in the first week (22 vs 6 min; p=0.028), for colicky crying in the second week (92 vs 73 min; p=0.041) and for TC in the second week (44 vs 29 min; p=0.024), demonstrating favour towards the acupuncture group.

CONCLUSIONS

Minimal acupuncture shortened the duration and reduced the intensity of crying in infants with colic. Further research using different acupuncture points, needle techniques and intervals between treatments is required.

Tetanization-induced pelvic-to-pudendal reflex plasticity in anesthetized rats

Reflex plasticity between pelvic afferent and pudendal efferent nerve fibers was examined in anesthetized rats. Brief high-frequency electric stimulation (300 pulses at 100 Hz) of the pelvic nerve afferent fiber produced a long-lasting potentiation of the pelvic-to-pudendal reflex (PPR). This tetanization-induced potentiation was abolished by a selective N-methyl-D-aspartate (NMDA) receptor antagonist and attenuated by a non-NMDA excitatory amino acid receptor antagonist. However, the GABA(A)-receptor antagonist had no effect on this potentiation. Both intrathecal glutamate (0.1 mM, 2-5 microl it) and NMDA (0.1 mM, 2-5 microl it) induced a potentiation of PPR similar to that of tetanization. Agonist-induced potentiation was shorter than tetanization-induced potentiation. The duration of the contraction wave of intraurethral pressure, elicited by PPR, was elongated by tetanization-induced potentiation, whereas the peak pressure was not affected. All these results demonstrate that brief high-frequency stimulation of the pelvic nerve afferent fiber can induce a distinct and long-lasting modulation in PPR activity and this change may be involved in nociceptive C afferent-induced obstructive urinary dysfunctions.

Depressor effect on blood pressure and flow elicited by electroacupuncture in normal subjects

To clarify the effect of electroacupuncture (Ea) on the activity of the cardiovascular system in normal individuals, hemodynamic parameters including arterial blood pressure (BP), finger blood flow (FBF) and heart rate (HR) as well as paravertebral temperature (PVT) were non-invasively recorded under Ea stimulation. Surface stimulation electrode was placed on the Hoku point (Li-4). Square wave pulses (0.05 ms) were applied from a stimulator with a stimulation frequency of 2 Hz (3 min). The stimulation intensity was five times of sensory threshold. BP and FBF were decreased (68.5+/-6.0%, P<0.01 and 96.8+/-1.1%, P<0.01 of control, respectively, n=7) while HR and PVT were increased significantly (115.0+/-5.1 of control, P<0.05 and 0.054+/-0.004 degree C, P<0.01, respectively, n=7) during Ea treatment. The results suggested an inhibition in sympathetic outflow, which induced vasodilatation of systemic arteriole and decrease in BP and FBF were elicited by Ea stimulation.