Long ago, Chinese people observed that stimulation to different points of human body could produce different sensations (sour, numbness, swelling, pain, etc.), physiological reactions (laughing, spontaneous limb movement, etc.) and therapeutic effects (alleviation of toothache, relief of dyspnea, etc.). Since these ancient times, the stimulations of heating with a lighted moxa (moxibustion), pressure with a human finger (acupressure), cupping with a vacuumed cup (cupping) and needling with a sterilized needle (acupuncture) have been extensively applied by Chinese clinicians to treat different diseases. With long-term practice from generation to generation, clinicians recognized that the points with same or similar effects were regularly located in a line. For example, the points in the line from the chest to the hand were effective for diseases in lung, trachea, pharynges and other body parts mostly related to respiratory system. This line was then termed the lung meridian, where the points are called lung meridian acupuncture points (acupoints) [1, 2].
The lung meridian acupoints have been accurately described in anatomic knowledge and located with scientific measurements, and their effects and manipulation methodologies have been introduced in detail. For example, Zhongfu ("Central Treasury"), as the first acupoint of Lung meridian, is named LU1. It is laterosuperior to the sternum at the lateral side of the first intercostals space, at 3/4 of distance from the frontal midline to the peak of shoulder. It alleviates cough, dyspnea, pain in the chest, shoulder and back, fullness of the chest, etc. Tiantu ("Heavenly Chimney"), as the 22nd acupoint of the Conception vessel, is named CV22. It is located at the center of the suprasternal fossa. It alleviates dyspnea, cough, sore throat, dry throat, hiccup, sudden hoarseness of the voice, difficulty in swallowing, goiter, etc. Liangmen ("Beam Gate"), as the 21st acupoint of the stomach meridian, is named ST21. It is located at 1/3 of the distance from the frontal midline to the edge of the body and at the level of 1/4 of distance from sternocostal angle to anus. It is used to treat gastric pain, vomiting, anorexia, abdominal distension, diarrhea, etc. [1, 2].
Acupuncture therapy for obstructive respiratory diseases has been effectively used in clinical practice in most Oriental countries for thousands years [3, 4]. In more recent times, this form of acupuncture therapy has attracted considerable attention in treating obstructive respiratory diseases (asthma, rhinosinusitis, chronic obstructive pulmonary diseases (COPD)) in Western countries [5–9]. The National Institute of Health (NIH) in a consensus statement derived from a Fall of 1997 consensus conference to assess acupuncture has indicated that acupuncture was useful in pain control and maybe a useful adjunct treatment for the management of asthma . Since many of the issues surrounding the clinical use of acupuncture relate to a perceived lack of scientific evidence, an evidence-based experimental approach should help to address some of these concerns.
Impaired mucociliary clearance (MC) mainly resulting from viscous airway secretion, resulting in airway obstruction, is not only among the most important features of airway inflammation in most obstructive respiratory diseases (e.g. COPD, asthma, acute bronchitis, cystic fibrosis, bronchiectasis) but also the major cause of death or poor quality of life in patients with the above respiratory diseases .
Since the needling manipulation of acupuncture is a special technique, only well-trained clinicians are authorized as acupuncture practitioners or acupuncturists. The stimulation by different acupuncturists may vary greatly, so the manipulation of needling is sometimes performed by electro-stimulation or electro-acupuncture (EA), in which the stimulation intensity can be regulated accurately by the current output and frequency, especially for acupuncture experiments. In recent years, electro-acupuncture has been employed by more and more acupuncturists worldwide to treat the above diseases in the clinic .
Although either regular acupuncture or electro-acupuncture has been demonstrated to facilitate nasal mucociliary clearance in patients with chronic rhinitis and polypous rhinosinusitis [13, 14], the research papers on the efficacies and mechanisms in animal models are limited. To investigate the efficacies and mechanisms, we applied both needle puncture (NP) and EA to our well-developed quail model, where human neutrophil elastase (HNE) was applied to simulate the human airway inflammatory conditions with impaired MC .
The contents of viscous components in the airway secretion, which are the key factors to airway secretion viscoelasticity (the key rheological property of airway secretion to affect MC), are thought to play an important role in impaired MC during inflammation status. We hypothesized that NP or EA may facilitate MC and that the facilitation of MC by NP or EA may partly result from decreasing the contents of viscous mucin and other macromolecules in airway secretion.
To confirm the above hypotheses, mucociliary transport velocity (MTV, a directly measurable parameter of MC) was measured, and fucose (a saccharide marker of viscous epithelial mucins) and protein (representative of macromolecules) contents were determined in the present experiment.