• The Korean Journal of Physiology
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• v.22 no.2
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• pp.231-243
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• 1988

This study was performed to investigate the mechanism of changes in arterial blood pressure, as a typical example of somatosympathetic reflex, induced by activation of muscular afferent nerves. Cats were anesthetized with ${\alpha}-chloraloae$ (60 mg/kg, i.p.). Afferent fibers in muscle nerve were activated by various method muscle contraction, electrical stimulation of muscle nerves, intraarterial injection of some algesic substances and noxious mechanical stimulation etc-and the evoked changes in arterial blood pressure were monitored. The effects of intravenous or direct spinal administration of morphine on the changes in arterial blood pressure induced by activation of the muscle afferent fibers were observed and also the effects of spinal lesions made in the $L1{\sim}L3$ spinal cord on them were studied to identify the ascending spinal pathways of the somatosympathetic reflexes. Followings are the results obtained. 1) The stimulation of medial gastrocnemius nerve under non-paralyzed condition with C-strength, low frequency (lower than 20 Hz) stimuli elicited a depressor response and a pressor response was elicited with C-strength, high frequency stimuli, of which the maximal response was observed at 100 Hz stimulation. 2) When the animal was paralyzed, depressor response to stimulation of the medial gastrocnemius nerve was observed with C-strength, $0.5{\sim}5Hz$ stimuli although the amplitude of the depressor response was decreased. The maximal pressor response was observed during stimulation with C-strength, $20{\sim}100Hz$ stimuli. 3) Intraarterial injection of some algesic substances induced marked pressor responses while noxious mechanical stimulation of the medial gastrocnemius muscle was not enough to elicit any significant changes (larger than 10 mmHg) in arterial blood pressure. 4) Systemically administered morphine (2 mg/kg) lowered the arterial blood pressure immediately and persistently and it was reversed by administration of naloxone. Direct spinally administered morphine did not elicit any changes. 5) The pressor response elicited by the activation of muscle afferent nerves was strengthened by systemic morphine administration while the depressor response tended to decrease. 6) Morphine administered on the spinal cord directly, decreased pressor response but did not change depressor response. From the above results it is concluded that there are separate groups of afferent nerves in the medial gastrocnemius nerve, which elicit pressor and depressor responses and the spinal ascending pathways of them are also separated from each other.

• The Korean Journal of Physiology
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• v.23 no.1
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• pp.129-138
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• 1989

In an attempt to characterize the ventral root afferent fibers, arterial blood pressure responses to stimulation of the ventral root (VR) were observed in anesthetized cats. Effects of the morphine administered either intravenously or direct spinally and of the spinal lesions on the pressor responses were compared. Followings are the results obtained. 1) Stimulation of the VR with C-strength, high frequency stimuli evoked a marked pressor response. No depressor response, which had been reported during peripheral nerve stimulation, was observed during VR stimulation with low frequency. 2) Acute cervical spinalization abolished the pressor response, indicating the involvement of supraspinal mechanism. 3) The ascending spinal pathways of the pressor response were located in the dorsolateral funiculus bilaterally. 4) Intravenously administered morphine exaggerated the pressor response to VR stimulation, while direct spinally administered morphine suppressed it. From the above results it was concluded that the ventral root afferent fibers have more similar properties to muscular C-afferent fibers than to cutaneous C-fibers.

• Journal of Chest Surgery
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• v.20 no.3
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• pp.439-450
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• 1987

The arterial blood pressure response elicited by stimulating the peripheral afferent fibers of different groups and origins was studied in cats. Experimental animals were anesthetized with a-chloralose [60mg/kg] and artificially ventilated with a respirator. The lumbosacral spinal cord was exposed through a laminectomy and L7 ventral root was isolated. The sural, medial gastrocnemius and common peroneal nerves were also exposed in the hindlimb. The arterial blood pressure was monitored continuously while the exposed peripheral nerves and L7 ventral root were being stimulated. Then, spinal lesions were made on the dorsolateral sulcus area, dorsolateral funiculus and other areas at the thoracolumbar junction. The arterial blood pressure responses were compared before and after making spinal lesions. The following results were obtained. 1. The mean arterial blood pressure was elevated from 103*7.3 to 129*8, 1 [mean*S.E.] mmHg [p<0.001] during stimulation of the sural nerve with C-strength [1000T], 20Hz. Stimulation with Ad-strength, 1Hz resulted in the depression of the arterial pressure by 8 mmHg [p<0.01]. 2. Stimulation of the medial gastrocnemius nerve with Ad-strength did not elicit any significant change in arterial blood pressure. Stimulation with C-strength, 20 Hz induced a pressor response from 102*6.2 to 117*6.4 mmHg [p<0.01] while that with C-strength, 1Hz induced a depressor response from 104*6.1 to 93*4.9 mmHg [p<0.001]. 3. A pressor response by 56 [from 107*7 5 to 163*9.4] mmHg [p<0.001] was induced during stimulation of the common peroneal nerve with C-strength, 20Hz stimuli. Stimulation with A4-strength, 1Hz depressed the arterial blood pressure from 111~9.3 to 94*7.8 mmHg [P<0.005]. The activation of the ventral root afferent fibers with C-strength, 20 Hz stimuli induced a pressor response by 22 mmHg [from 115*9.4 to 137*8.6 mmHg] [p<0.001]. 4. The pressor response elicited during stimulation of the sural nerve was abolished by making lesions on the dorsolateral sulcus area bilaterally. With the medial gastrocnemius nerve, the pressor response had not been abolished completely by the dorsolateral sulcus lesions. The pressor response disappeared completely with addition of the bilateral dorsolateral funiculus lesions. 5. The depressor response induced by stimulation of the sciatic nerve with Ad-strength, 1Hz was decreased by making lesions on the dorsolateral funiculus. 6. From the above results it is concluded that the difference in the blood pressure responses to the activation of the muscular afferent and the cutaneous afferent fibers is responsible for the groups of afferent fibers and the spinal ascending pathways.

• Korean Journal of Acupuncture
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• v.26 no.4
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• pp.195-209
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• 2009

Objectives : Transient inflammation has been demonstrated to alter visceral sensory function in animal models and acute mucosal inflammation may precede the manifestation of visceral hyperalgesia. Thus in this study we compared effects of herbal acupuncture of Nidus Vespae (NV) applied to the different acupoints in the acute colitis induced by trinitrobenzenesulphonic acid (TNBS) intracolonic injection in rats. Methods : In Male Sprague-Dawley rats, weighing 250 ~ 400 g, TNBS (5 mg/kg) was infused intrarectally through a silicon rubber catheter into the anus under isoflurane anaesthesia. Under general anesthesia, acupoints of LI4 (Hapkok), SI25 (Cheonchu), ST36 (Joksamni), BL25 (Daejangsu) were intramuscularly injected by NV. Expressions of cFos protein in the periaqueductal gray (PAG), locus coeruleus (LC), nucleus of solitary tract (Sol), and the 6th lumbar spinal cord (L6 s.c.) were observed at 24 hrs after TNBS induced colitis by immunohistochemistry. Results : The expression of c-Fos protein in L6 s.c., Sol, LC and PAG increased 24 hrs after TNBS injection into colorectum as compared to normal group. NV herbal acupuncture also inhibited the expression of c-Fos protein in Sol but not L6 s.c., LC, and PAG. NV to ST36 inhibited significantly the c-Fos expression in Sol and PAG. NV to ST25 inhibited the c-Fos protein expression all over the observation area. NV to BL25 showed the inhibitory effects in the areas except LC. Whether or not a role of endogenous opioids, intrathecal injection of naltrexone (30 ug / 30 ul) was applied before the 2nd herbal acupuncture treatment 24 hrs after TNBS-induced colitis in rat. Naltrexone reversed the inhibition of c-Fos protein expression in the spinal cord and brainstem under different conditions such as type of herbal acupuncture compound and choice of acupoint. Conclusions : In summary, these data show that herbal acupuncture of NV inhibits signal pathways such as spinal cord and brain stem ascending hypersensitivity of colorectum after TNBS induced colitis. This effect may be mediated by acupoints through the endogenous opioid system involving the pain modulation.

• Journal of Pharmacopuncture
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• v.13 no.3
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• pp.47-62
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• 2010

Objectives: Colitis is an inflammatory bowel disease characterized by colonic mucosal inflammation and chronic relapsing events represents. The purpose of this study is to evaluate effects of pharmacopuncture of anti-inflammatory herbal compound (AiC) applied to the different acupoints in the acute colitis induced by trinitrobenzenesulphonic acid (TNBS) intracolonic injection in rats. Methods: In Male Sprague - Dawley rats, weighing 250~400g, TNBS (5 mg/kg) was infused intrarectally through a silicon rubber catheter into the anus under isoflurane anaesthesia. Acupoints of LI4 (Hapkok), ST25 (Cheonchu), ST36 (Joksamni), and BL25 (Daejangsu) were intramuscularly injected by AiC, respectively (injection volume & times: 0.2 ml / acupoint, twice times on the 2nd & 3rd day). Expressions of cFos protein in the periaqueductal gray (PAG), locus coeruleus (LC), nucleus of solitary tract (Sol), and the 6th lumbar spinal cord (L6 s.c.) were observed at 24 hr after TNBS induced colitis by immunohistochemistry. Results: The expression of c-Fos protein in the L6 s.c., Sol, LC and PAG increased 24 hr after TNBS injection into colorectum as compared to normal and 50% ethanol treated group. AiC to LI4 inhibited the expression of c-Fos protein in Sol and PAG but not L6 s.c. and LC. AiC to ST36 showed significant inhibition the c-Fos expression in L6 s.c., Sol and PAG. AiC to ST25 only showed the effects in L6 s.c. and PAG. AiC to BL25 inhibited significantly the expression of c-Fos protein all over the areas. To investigate whether or not endogenous opioids are involved, intrathecal injection of naltrexone (30ug/30ul) was applied before the 2nd pharmacopuncture treatment 24 hr after TNBS-induced colitis in rat. Naltrexone reversed the inhibition of c-Fos protein expression in the spinal cord and brainstem. Conclusions: These data show that pharmacopuncture of Aic potently inhibits signal pathways ascending hypersensitivity of colorectum after TNBS induced colitis and depends on the endogenous opioids according to acupoints.