Mechanisms about the effect of different acupuncture manipulation methods on body temperature / 中国针灸

<p><b>OBJECTIVE</b>To introduce studies about the effect of different needling manipulation methods on the body surface temperature in recent years, and to probe the mechanism.</p><p><b>METHODS</b>It is reviewed from clinical studies and experimental studies, and other aspects.</p><p><b>CONCLUSION</b>The functions and therapeutic effects of acupuncture are changed with temperature changes induced by different needling manipulations. Reinforcing method of acupuncture can increase body temperature, and the reducing manipulation can decrease it. The temperature of body surface is decided by blood circulation, excitement extent of the sympathetic nerve, and metabolic state of the tissues, and other aspects, which are related with the changes of skin temperature induced by different needling manipulation methods.</p>

Adrenomedullin reduces intracellular calcium concentration in cultured hippocampal neurons / 生理学报

The effects of adrenomedullin (ADM) on intracellular calcium concentration ([Ca(2+)](i)) were investigated in cultured hippocampal neurons. Changes in [Ca(2+)](i) were detected by laser scanning confocal microscopy using Fluo 3-AM as the calcium fluorescent probe. [Ca(2+)](i) was represented by relative fluorescent intensity. The results showed that: (1) ADM (0.01-1.0 micromol/L) decreased the resting [Ca(2+)](i) in a concentration-dependent manner. (2) Calcitonin gene-related peptide receptor antagonist CGRP(8-37) significantly inhibited the effects of ADM. (3) ADM significantly reduced the increase in [Ca(2+)](i) induced by high K(+). (4) ADM markedly inhibited the inositol 1,4,5-trisphosphate (IP(3))-induced increase in [Ca(2+)](i), while did not influence ryanodine-evoked increase in [Ca(2+)](i). These results suggest that ADM reduces [Ca(2+)](i) in cultured hippocampal neurons through suppressing Ca(2+) release from IP(3)-sensitive stores. Although ADM does not alter resting Ca(2+) influx, it significantly suppresses Ca(2+) influx activated by high K(+). These effects may be partly mediated by CGRP receptors. ADM in the CNS may act as a cytoprotective factor in ischemic/hypoxic conditions.

Effect of intracerebroventricular injection of adrenomedullin on catecholaminergic neurons and expression of c-fos in the rat brain nuclei involved in cardiovascular regulation / 中国应用生理学杂志

<p><b>AIM AND METHODS</b>Using double immunohistochemical method for Fos and tyrosine hydroxylase(TH) to examine the effects of intracerebroventricular (icv) administration of adrenomedullin (AM) on catecholaminergic neurons and the expression of c-fos gene in rat brain nuclei involved in cardiovascular regulation in order to define whether the effects of central administration of adrenomedullin (AM) were induced by activating the catecholaminergic neurons.</p><p><b>RESULTS</b>(1) Following icy administration of AM (3 nmol/kg), Fos-like immunoreactivity neurons were markedly increased in several brain areas of the rat, including the brainstem, the hypothalamus and the forebrain. (2) Following icy administration of AM (3 nmol/kg), double-labeled neurons for Fos and TH increased significantly in the area postrema (AP), the nucleus of the solitary tract (NTS), the nucleus paragigantocellularis lateralis (PGL) and the locus coeruleus (LC). (3) Pretreatment with calcitonin gene-related peptide receptor antagonism CGRP (8-37) (30 nmol/kg) significantly reduced the action of AM (3 nmol/kg) in the brain.</p><p><b>CONCLUSION</b>AM activates the nuclei involved in cardiovascular regulation in the forebrain, the hypothalamus and the brainstem, and that the central actions of AM are induced by activating the catecholaminergic neurons of brainstem nuclei involved in cardiovascular regulation. CGRP receptor can mediate the effects of AM in brain.</p>

Intracerebroventricular administration of adrenomedullin increases the expression of c-fos and activates nitric oxide-producing neurons in rat cardiovascular related brain nuclei / 生理学报

To define the action sites of adrenomedullin (ADM) in the rat brain, and to examine whether neuronal NO may participate in the actions of ADM, the present study was undertaken to examine the effects of i.c.v. administration of ADM on the induction of Fos protein and on nitric oxide-producing neurons in rat brain nuclei involved in cardiovascular regulation, using double immunohistochemical method for Fos and neuronal nitric oxide synthase (nNOS). Following i.c.v. administration of ADM (1 nmol/kg, 3 nmol/kg), Fos-like immunoreactivity neurons were markedly increased in several brain areas of the rat, including the nucleus of the solitary tract (NTS), the area postrema, the locus coeruleus, the parabrachial nucleus and the nucleus paragigantocelluaris laterialis (PGL) in the brainstem, the paraventricular nucleus (PVN), the supraoptic nucleus (SON) and the ventromedial hypothalamic nucleus in the hypothalamus, as well as the central amygdaloid nucleus and the lateral habenular nucleus in the forebrain. Following i.c.v. injection of ADM (1 nmol/kg, 3 nmol/kg), the number of double-labeled neurons for Fos and nNOS was increased in the PVN and SON. Small numbers of double-labeled neurons were also found in the NTS and PGL following i.c.v. injection of ADM (3 nmol/kg), while i.c.v. injection of ADM (1 nmol/kg) did not change the number of double-labeled neurons in the NTS and PGL. Pretreatment with calcitonin gene-related peptide receptor antagonist CGRP(8-37) (30 nmol/kg) significantly reduced the action of ADM (3 nmol/kg) in the brain. These results suggest that centrally administered ADM may increase the expression of c-fos in the forebrain, the hypothalamus and the brainstem and activate nitric oxide-producing neurons in the PVN, SON, NTS and PGL. These effects may be partly mediated by CGRP receptors.

Effects of agmatine on the electrical activity of subfornical organ neurons / 生理学报

The aim of this study was to investigate the effects of agmatine (Agm) on the electrical activity of neurons in subfornical organ (SFO) slices using extracellular recording technique. The results are as follows. (1) In response to the application of Agm (1.0 micromol/L) into the superfusate for 2 min, the discharge rate of 24/28 (85.7%) subfornical neurons was decreased significantly, while the discharge rate of 4/28 (14.3%) neurons were not affected. (2) Pretreatment with L-glutamate (0.3 mmol/L) led to a marked increase in the discharge rate of 19/24 (79.2%) subfornical neurons in an epileptiform pattern and the activity of the remaining 5/24 (20.8%) neurons was unaffected. By application of Agm (1.0 micromol/L) into the superfusate for 2 min, the epileptiform dicharge of 15/19 (78.9%) neurons was suppressed significantly, while that of the other 4 (21.1%) neurons was not inhibited. (3) In 12 neurons, perfusion of the selective L-type calcium channel agonist, Bay K-8644 (0.1 micromol/L), induced a significant increase in the discharge rate of 10/12 (83.3%) neurons, while the other 2 (16.7%) neurons showed no change. The increased discharge of 8/10 (80%) neurons was reduced by application of Agm (1.0 micromol/L) into the superfusate and that of 2/10 (20%) neurons was not affected. (4) Application of nitric oxide synthase (NOS) inhibitor N(G)-nitro-L-arginine methyl ester (L-NAME, 50 micromol/L) into the superfusate also significantly increased the discharge rate of 6/9 (66.7%) neurons, and that of 3/9 (33.3%) neurons had no response. Agm (1.0 micromol/L) applied into the superfusate reduced the increased discharge of all 6/6 (100%) neurons. These results suggest that Agm can inhibit the spontaneous discharge, and L-glutamate, Bay K-8644- or L-NAME-induced discharge of neurons in SFO. These inhibitory effects of Agm may be related to the blockade of NMDA receptors and reduction in calcium influx in SFO neurons.

A simple and new type of drop recorder mainly applied in the experiment of frog heart / 中国应用生理学杂志

<p><b>AIM</b>To introduce the manufacture and use of a simple, new type of drop recorder of frog heart.</p><p><b>METHODS</b>To improve the perfusion device of (see text for symbol) and Straub method. Two electrodes of drop recorder were fixed in an injector of 20 ml. The input tube, output tube and resistance tube were all made of plastic material.</p><p><b>RESULTS</b>This device could be used to observe effects of preload, after-load, hormone and electrolyte on the cardiac output in isolated frog heart.</p><p><b>CONCLUSION</b>The new type of drop recorder was economical and could be easily operated, it could be also connected to computer. Using the new type of drop recorder, effects of various physical and chemical factors on cardiac function could be observed directly, accurately.</p>

Effect of intracarotid administration of adrenomedullin on the spontaneous electrical activity of area postrema neurons in sino-aortic denervated rats / 生理学报

To observe the effect of intracarotid administration of adrenomedullin (AM) on the spontaneous electrical activity of area postrema (AP) neurons, 78 spontaneous active units were recorded from 63 sino-aortic denervated Sprague-Dawley rats using extracellular recording technique. The results obtained are as follows. (1) Following intracarotid administration of AM (0.3 nmol/kg), the discharge rate of 47 out of 78 units increased markedly from 2.99+/-0.24 to 4.79+/-0.29 spikes/s (P<0.001), 20 units decreased from 3.24+/-0.46 to 1.97+/-0.37 spikes/s (P<0.001), and the remaining 11 showed no response. Blood pressure (BP) and heart rate (HR) did not change throughout the experimentation. (2) Pretreatment with intracarotid administration of calcitonin gene-related peptide receptor antagonist CGRP8-37 (3 nmol/kg) did not change the effects of AM. (3) Following intracarotid injection of NO precursor L-arginine (30 mg/kg), the excitatory effect of AM was attenuated. The above results indicate that AM can excite spontaneous electrical activity of AP neurons, this effect is not mediated by calcitonin gene-related peptide receptor but may be attenuated by NO precursor L-arginine.

Microinjection of adrenomedullin into rostral ventrolateral medulla increases blood pressure, heart rate and renal sympathetic nerve activity in rats / 生理学报

The present study was undertaken to examine the effects of microinjection of adrenomedullin (AM) into rostral ventrolateral medulla (RVLM) on mean arterial pressure (MAP), heart rate (HR) and renal sympathetic nerve activity (RSNA) in 34 anesthetized Sprague-Dawley rats. The results obtained are as follows. (1) Following microinjection of AM (10 micromol/L, 200 nl) into the RVLM, MAP, HR and RSNA were significantly increased from 99.09+/-3.32 mmHg, 370.78+/-7.84 bpm and 100+/-0% to 113.57+/-3.64 mmHg (P>0.001), 383.28+/-7.38 bpm (P>0.001) and 123.72+/-2.74% (P>0.001), respectively. (2) Pretreatment with microinjection of calcitonin gene-related peptide receptor antagonist CGRP8-37 (100 micromol/L, 200 nl) did not change the effects of AM. (3) L-arginine (100 mg/kg, 0.2 ml, i.v.), an NO precursor, abolished the effects of AM. This study demonstrates that AM acting at the rostral ventrolateral medulla may produce significant cardiovascular responses, the effects are not mediated by CGRP receptor but may be abolished by NO.