BACKGROUND: Neuromuscular blocking drugs are designed to specifically block nicotinic cholinergic receptors at the neuromuscular junction, but many bind to muscarinic cholinergic receptors on ganglia, nerve endings, and smooth muscles, thereby altering parasymphathetically mediated airway caliber and heart rate. METHODS: We studied the effects of mivacurium on the tension of tracheal smooth muscle by using an isolated rat tracheal preparation. We studied the cumulative effect of acetylcholine after pretreating the tracheal smooth muscle with mivacurium at different concentrations, as well as the effect of L-NAME and propranolol on the tension of tracheal smooth muscle after pretreating with mivacurium. RESULTS: Mivacurium shifted the acetylcholine dose-response curve to the right. L-NAME and propranolol had no effect on the tension of tracheal smooth muscle after pretreating with mivacurium. CONCLUSIONS: We have found that mivacurium relaxes isolated rat tracheal smooth muscle and this effect has no relationship to beta-receptors or nitric oxide.
Acetylcholine ; Animals ; Ganglia ; Heart Rate ; Muscle, Smooth ; Nerve Endings ; Neuromuscular Blockade ; Neuromuscular Junction ; NG-Nitroarginine Methyl Ester ; Nitric Oxide ; Propranolol ; Rats* ; Receptors, Cholinergic

To verify the postoperative ultrastructural changes of the myotendinous nerve endings of feline extraocular muscles, which are known as proprioceptors. Sixteen recti of four cats were used and divided into three groups. In group A, eight lateral recti were recessed. In group B, four medial recti were resected by 10 mm from insertion to include the myotendinous junction. In group C, four medial recti were resected by 4 mm of muscle bellies only, without disturbing the myotendinous junction. Four weeks after surgery, specimens were examined with electron microscopy. In group A, overall neural structures were well maintained with slight axonal degeneration. In group B, only muscle fibers were observed without any regeneration of neural sprouts. In group C, axonal disintegration and shrinkage were evident. These results indicate that myotendinous nerve endings can be damaged in strabismus surgery, and that resection was more invasive than recession in disrupting myotendinous nerve endings.
Animals ; Cats ; Motor Neurons/ultrastructure ; Nerve Endings/*ultrastructure ; Neuromuscular Junction/*ultrastructure ; Oculomotor Muscles/*innervation/surgery ; Oculomotor Nerve/*ultrastructure ; *Ophthalmologic Surgical Procedures ; Receptors, Sensory/ultrastructure ; Strabismus/surgery ; Tendons/*innervation/ultrastructure

Animals ; Electric Stimulation ; Hippocampus ; physiology ; Male ; Nerve Endings ; physiology ; Rats ; Rats, Sprague-Dawley ; Vagus Nerve ; physiology

Remote ischemic preconditioning (RIPC) is an intrinsic phenomenon whereby 3~4 consecutive ischemia-reperfusion cycles to a remote tissue (noncardiac) increases the tolerance of the myocardium to sustained ischemiareperfusion induced injury. Remote ischemic preconditioning induces the local release of chemical mediators which activate the sensory nerve endings to convey signals to the brain. The latter consequently stimulates the efferent nerve endings innervating the myocardium to induce cardioprotection. Indeed, RIPC-induced cardioprotective effects are reliant on the presence of intact neuronal pathways, which has been confirmed using nerve resection of nerves including femoral nerve, vagus nerve, and sciatic nerve. The involvement of neurogenic signaling has been further substantiated using various pharmacological modulators including hexamethonium and trimetaphan. The present review focuses on the potential involvement of neurogenic pathways in mediating remote ischemic preconditioning-induced cardioprotection.
Brain ; Femoral Nerve ; Hexamethonium ; Ischemic Preconditioning* ; Myocardium ; Negotiating ; Nerve Endings ; Neurons ; Sciatic Nerve ; Sensory Receptor Cells ; Trimethaphan ; Vagus Nerve

The cholinergic and adrenergic nerve innervation and nerve endings of the iris muscle in Cynomolgus monkey eye is studied by electron microscopy. In the iris, the sphincter muscle reveals nerve terminals containing small empty vesicle which is said to be cholinergic in a greater number (about 85% of nerve terminals) and those containing small cored vericles which is said to be adrenergic in a fewer number (about 15% of nerve terminals) and the latter are more frequently found in the region of peripheral one third of the sphincter muscle then the rest two thirds. In the dilator muscle 65% of the nerve terminals is found to be adrenergic and 35% cholinergic. A dual innervation, adrenergic and cholinergic nerves in both the iris dilator and the sphincter muscle, is not clearly explained in their functions, that is, how influence two nerves one another in addition to the effector cells. A single or double layer of basement membrane lies between the nerve terminals and adjacent muscle in the stromal site of iris muscle. In part the close apposition of the nerve with muscle membrane is seperated by an intercellular space of about 200 A, which is much more in the muscle bundles than in the peripheral portion of the sphincter muscle, however a few in the dilator muscle. The two or three adrenergic and cholinergic axons or terminals in the iris muscle are often closely adjacent to one another, which nerve terminals are not clarified, whether two nerves is motor, or afferent and efferent nerve unit.
Axons ; Basement Membrane ; Extracellular Space ; Haplorhini* ; Iris* ; Macaca fascicularis ; Membranes ; Microscopy, Electron ; Nerve Endings*

PURPOSE: Hands are the chief organs for physically manipulating the environment, using anywhere from the roughest motor skills to the finest, and since the fingertips contain some of the densest areas of nerve endings on the human body, they are continuously used organ with complex functions, and therefore, often gets injured. To prevent any functional loss, a detailed anatomical knowledge is required to have a perfect surgical treatment. Also it is necessary to have a thorough understanding of arrangements of the human extensor tendons and intertendinous connections when tenoplasty or tendon transfer is required. We performed a study of the arrangements of the human extensor tendons and the configuration of the intertendinous connections over the dorsum of the wrist and hand. METHODS: A total of 58 hands from Korean cadavers were dissected. The arrangements of extensor indicis proprius, extensor digitorum communis, and extensor digiti minimi tendons and intertendinous connections were studied. RESULTS: The most common distribution patterns of the extensor tendons of the fingers were as follows: a single extensor indicis proprius(EIP) tendon which inserted ulnar to the extensor digitorum-index(EDC-index); a single EDC-index; a single EDC-middle; a double EDC-ring; an absent EDC-little; a double extensor digiti minimi(EDM), a single EDC-index(98.3%), a single EDC-middle(62%), a double EDC-ring(50%), and an absent(65.5%) or a single (32.8%) EDC-little. A double(70.6%) EDM tendons were seen. Intertendinous connections were classified into 3 types: type 1 with thin filamentous type, type 2 with a thick filamentous type, and type 3 with a tendinous type subdivided to r shaped 3r type and y shaped 3y type. The most common patterns were type 1 in the 2nd intermetacarpal space, type 2 in the 3rd intermetacarpal space, and type 3r in the 4th intermetacarpal space. And in the present study, we observed one case of the extensor digitorum brevis manus(EDBM) on the boht side. CONCLUSION: A knowledge of both the usual and possible variations of the extensor tendon and the intertendinous connection is useful in the identification and repair of these structures.
Cadaver ; Fingers ; Hand ; Human Body ; Humans ; Motor Skills ; Nerve Endings ; Tendon Transfer ; Tendons ; Wrist

BACKGROUND: The effect of substance P (SP) on the hyperalgesia induced by inflammation is controversial, and as SP remains in the periphery just for a short period of time after release from the nerve ending, the contribution of SP on the development of sustained mechanical hyperalgesia in rats with inflammation is questionable. The purpose of this experiment is to evaluate the effect of SP on the development of mechanical hyperalgesia induced by Freund's complete adjuvant (FCA) using SP antagonist [D-Arg, D-Phe, D-Trp, Leu]-substance P (SPA). METHODS: Male Sprague Dawley rats were divided into four groups; control (normal saline) and three different doses of SPA (0.25 microgram, 2.5 microgram, 25 microgram/0.1 ml). Inflammation was induced in rats by injecting 0.15 ml of FCA intraplantarly. Rats showed typical hyperalgesia within 12 hours after injection and maintained it for about one week. To test the effect of SPA on the developement of inflammation, either SPA or saline was injected at 1 h before and at the time of FCA injection under light halothane anesthesia after a baseline test. The effect of SPA on hyperalgesia was assessed by measuring mechanical hyperalgesia at 2, 6, 12, 24 hrs and 4 days after injection of the drug. To test the effect of SPA on fully developed inflammation, tests were done 2 days after injection of FCA. Mechanical hyperalgesias were assessed at 15, 30, 60, 90, 120 min after the drug injections. RESULTS: SPA injected to suppress the initial SP spill over decreased the mechanical hyperalgesia in a dose dependent manner. SPA injected after the full development of inflammation also decreased mechanical hyperalgesia. CONCLUSIONS: SP released at the initial phase of inflammation as well as SP released after the development of inflammation are all important for the maintainance of mechanical hyperalgesia.
Anesthesia ; Animals ; Halothane ; Humans ; Hyperalgesia* ; Inflammation* ; Male ; Nerve Endings ; Rats* ; Rats, Sprague-Dawley ; Substance P*

The mental foramen is a bilateral opening in the vestibular portion of the mandible through which nerve endings, such as the mental nerve, emerge. In general, the mental foramen is located between the lower premolars. This region is a common area for the placement of dental implants. It is very important to identify anatomical variations in presurgical imaging exams since damage to neurovascular bundles may have a direct influence on treatment success. In the hemimandible, the mental foramen normally appears as a single structure, but there are some rare reports on the presence and number of anatomical variations; these variations may include accessory foramina. The present report describes the presence of accessory mental foramina in the right mandible, as detected by cone-beam computed tomography before dental implant placement.
Anatomic Variation ; Bicuspid ; Cone-Beam Computed Tomography* ; Dental Implants ; Mandible ; Nerve Endings

Although the conclusion is controversial, there has long been an appealing notion that catecholamines may be involved in some way in the pathogenesis of primary hypertension and almost invariably most of hypotensive drugs involve at various sites of the neuron and produce their effect by depletion of norepinephrine in the sympathetic nerve ending. The authors undertook the comparative study on catecholamine depleting action of 3 most effective drugs available for the treatment of hypertension, reserpine, guanethidine and alpha-methyldopa, measuring the plasma catecholamine levels and urinary exceretion of caecholamine by the modified fluorometric method of Weil-Malherbe and Bone during the treatment of hypertension. The results are as follows: 1) Before the administration of hypotensive drugs, mean blood pressure was 180/110mmH, mean psalma epinephrine level was 0.36+/-0.23gamma%, mean plasma norepinephrine level was 0.48+/-0.35gamma%, 24 hours urinary excretion of epinephrine was 3.6+/-0.12gamma/day and 24 hours urinary excretion of norepinephrine was 68.9+/-0.34gamma/day. 2) In group 1 (reserpin administered group), the mean blood pressure was 190/110mmHg before the treatment and which was declined to 155/89mmHg on the last day of 4th week, in group 2 (guanethidine administered group), the mean blood pressure measured before the treatment was 185/110mmHg and which was declined to 150/85mmHg on the last day of 4th week, and in group 3 (alpha-methylodpa administered group), the mean blood measured pressure measured before the treatment was 182/110mmHg and which was declined to 153/88mmHg on the last day of 4th week. 3) After the treatment for 4 weeks with reserpin guanethidine and alpha-methyldopa, the mean plasma epinephrine levels were declined from 0.37+/-0.12gamma% to 0.11+/-0.08gamma% in group 1, from 0.38+/-0.16gamma% to 0.14+/-0.10gamma% in group 2 and from 0.33+/-0.23gamma% to 0.10+/-0.09gamma% in group 3. 4) The mean plasma norepinephrine levels were declined from 0.05+/-0.21gamma% to 0.22+/-0.12gamma% in group 1, from 0.51+/-0.25gamma% to 0.20+/-0.10gamma% in group 2 and from 0.51+/-0.21gamma% to 0.20+/-0.11gamma% in group 3 after the treatment of 4 weeks respectively. 5) Urinary exceretion of epinephine was declined from 32.3+/-0.16gamma/day to 10.4+/-0.10gamma/day in group 1, from 34.5+/-0.34gamma/day to 17.2+/-0.16gamma/day in group 2, and from 28.2+/-0.14gamma/day to 10.3+/-0.11gamma/day in group in group 3 after the treatment of 4weeks duration. 6) The mean value of 24 hours urinary excretion of norepinephrine was declined to from 72.2+/-0.35gamma/day to 28.5+/-0.14gamma/day in group1, from 69.2+/-0.34gamma/day to 22.6+/-0.21gamma/day in group 2 and from 68.6+/-0.34gamma/day to 18.2+/-0.10gamma/day in group 3 after the treatment of 4 weeks duration. 7) From the above result we can summarized as follows: Antihypertensive effect of each drugs was; guanethidine>alpha-methylodopa>reserpin in order but depressing action plasma norepinephrine levels was; alpha-methyldopa>guanethidine>reserpin and depressing effect of urinary norepinephrine excretion was; alpha-methyldopa>guanethidine>reserpin, in order.
Antihypertensive Agents* ; Blood Pressure ; Catecholamines ; Epinephrine ; Guanethidine ; Humans ; Hypertension ; Methyldopa ; Nerve Endings ; Neurons ; Norepinephrine ; Plasma* ; Reserpine

PURPOSE: To demonstrate the presence of nerve fibers including nociceptive fibers in synovium of human knee joint using immunohistochemistry. MATERIALS AND METHODS: 10 Synovial membrane tissues of knee joint obtained from 5 cadavers were analyzed immunohistochemically using antibodies to protein gene product 9.5, betaIII-tubulin, substance P and calcitonin gene-related peptide (CGRP). RESULTS: Many nerve fibers immunoreactive for protein gene product 9.5 and betaIII-tubulin were demonstrated in synovial folds of human knee joints. Also, immunostaining showed the presence of free nerve ending fibers immunoreactive for substance P and calcitonin gene-related peptide in synovium. CONCLUSION: The presence of putative nerve fibers including nociceptive fibers in synovial folds supports a possible role for theses structures as source of knee joint pain.
Antibodies ; Cadaver ; Calcitonin Gene-Related Peptide ; Humans* ; Immunohistochemistry ; Knee Joint ; Knee* ; Nerve Endings ; Nerve Fibers* ; Substance P ; Synovial Membrane*