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Objective: To observe the effects of activation or blockade of the prelimbic (PrL) α1-adrenoceptors on anxiety-like behaviors and amygdaloid neural activities in rats with Parkinson's disease (PD). Methods: The rat model of PD was established by 6-hydroxydopamine (6-OHDA) unilateral lesion of the medial forebrain bundle (MFB). Then the anxiety-like behavior of rats was detected by the open field test. In addition, the changes of anxiety-like behavior, the effects of PrL α1-adrenoceptor stimulation on monoamines and c-Fos expression in the amygdala were also observed after local injection of the selective α1-adrenoceptor agonist or antagonist into the PrL by guided cannula. Results: Unilateral 6-OHDA lesions of the MFB in rats induced anxiety-like behaviors (P<0.001). Furthermore, activation of the PrL α1-adrenoceptors significantly induced or enhanced anxiety-like behaviors in the rats (sham group: P<0.001; lesion group: P<0.05), while blockade of the α1-adrenoceptors produced anxiolytic effects (sham group: P<0.001; lesion group: P<0.05). Then activation of the PrL α1-adrenoceptors increased the levels of DA and 5-HT while blockade of the PrL α1-adrenoceptors decreased DA and 5-HT levels in the amygdala in sham-operated rats (DA & 5-HT: P<0.001). However, compared to those of sham-operated rats, activation of the PrL α1-adrenoceptors increased the levels of NA and 5-HT while blockade of the PrL α1-adrenoceptors decreased NA and 5-HT levels in the amygdala in the lesioned rats (NA & 5-HT: P<0.001). In addition, the density of c-Fos immunoreactive positive neurons in the amygdala increased after intra-PrL injection α1-adrenoceptors agonist phenylephrine (sham group & lesion group: P<0.001). Conclusion: These findings indicate that changed neural activities in the amygdala after activation or blockade of the PrL α1-adrenoceptors are involved in regulating anxiety-like behaviors in PD rats.
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Objective@#To detect the single nucleotide polymorphism (SNP) at locus 1 165 of β1-adrenoceptor (β1-AR) and to investigate the association between the SNP and the infection by enterovirus A71(EV-A71).@*Methods@#Polymerase chain reaction (PCR) amplification technique was used to detect the SNP at locus 1 165 of β1-AR between hand, foot and mouth disease (HFMD) and healthy controls by sanger sequencing method .@*Results@#There was a G1165C SNP and three kinds of genotypes (GG, GC, CC) in β1-AR gene in the 77 cases of EV-A71 HFMD patients and 66 cases of healthy controls. For HFMD patients, frequencies of GG, GC and CC genotypes of the G1165C locus were 10%, 47% and 43%, respectively, and alleles frequency of G and C were 34% and 66%, respectively. But in healthy children, GG, GC, CC genotype frequencies were 7%, 41% and 52%, respectively, and G and C allele frequencies were 28% and 72% respectively. Chi-square analysis showed that there were no significant differences in distribution of genotypes (χ2=1.154, df=2, P=0.562) and alleles frequency (χ2=1.091, df=2, P=0.296) between the EV-A71-infected group and the healthy control group. Between mild and severe EV-A71-infected group, there were no significant differences in distribution of genotypes (χ2=3.945, df=2, P=0.139) and alleles frequency (χ2=3.763, df=2, P=0.052).@*Conclusions@#The 1 165 SNP in the coding region of β1-AR was not associated with EV-A71 infection and its severity.
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Aim To investigate the effects of mmLDL on the up-regulation ofα1 receptors in moues mesenter- ic arteries. Methods Mice tail intravenous injection of mmLDL was used . Vitro sensitive myograph was empl- oyed to examine Noradrenaline ( NA) induced vascular contraction on mice mesenteric artery, and the mRNA and protein expressions ofα1 andα2 receptors were an-alyzed by real-time PCR and Western blot, respective-ly. Results mmLDL significantly increased NA in-duced concentration-contractile curve, and the data of Emax and pEC50 were from ( 122. 61 ± 9. 40 )% and (5. 65 ± 0. 05 ) in normal saline ( NS ) group to (161. 01 ± 6. 90 )% and ( 6. 20 ± 0. 08 ) in mmLDL group (P tion-contractile curve induced by NA towards right. Af-ter using mmLDL, the mRNA and protein levels of α1 adrenoceptor were significantly increased, but the mR-NA and protein levels of α2 adrenoceptor were not changed. Conclusion Tail intravenous injection of mmLDL enhances the vascular expressions of α1 adre-noceptors and the contractile effects mediated byα1 ad-renoceptors.
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Aim To analyze the blocking effect of ( ± ) doxazosin [ ( ± ) DOX ] , ( -) doxazosin [ ( -) DOX] and ( +) doxazosin [( +) DOX] on the vaso-constriction of rat isolated mesenteric arterioles media-ted by α1-adrenoceptors. Methods The vasoconstric-tion induced by phenylephrine ( Phe) in the rat isola-ted mesenteric arterioles ( the second- and third-order branches) was recorded using DMT wire myograph sys-tem 620M, and theα1-adrenoceptor antagonistic activ-ity of ( ± ) DOX and its enantiomers was analyzed. Results The inner diameter of second- and third-or-der branches of the rat mesenteric artery was (162. 5 ± 5. 3) μm (n=11) and (103. 1 ± 2. 3) μm (n=23), respectively. The values of normalized preload of the second-and third-order branches, which were calculat-ed by the LabChart software, were (2. 93 ± 0. 51) mN ( n =11 ) and ( 2. 64 ± 0. 50 ) mN ( n =23 ) ( P >0. 05 ) . Vasoconstrictive responses to Phe in the sec-ond-order branche of rat mesenteric artery under nor-malized preloads were not significantly different from those under 5 mN preload;however, the Emax values of the Phe-induced vasoconstriction under 10 mN, 15 mN and 20 mN preloads were decreased by 12%, 29%and 43% ( P<0. 01 ) respectively compared with those under normalized preload. The concentration-response curves for Phe were shifted to right in a concentration dependent manner by ( -) DOX or ( +) DOX at 0. 001 , 0. 01 and 0. 1 μmol · L-1 without significant change in their Emax values in the second-and third-or-der branches of rat mesenteric artery. Schild plot anal-ysis indicated that ( -) DOX, ( +) DOX and ( ± ) DOX non-competitively inhibited the vasoconstrictive responses to Phe in the second-order branches, and the rank order of pKB values was ( +) DOX ( 8. 67 ± 0. 10 ) , ( ± ) DOX ( 8. 53 ± 0. 090 ) , ( -) DOX (7. 85 ± 0. 09). However, schild plot analysis indica-ted that ( -) DOX and ( +) DOX competitively inhibi-ted the vasoconstrictive responses for Phe in the third-order branch, and the rank order of their pKB values was ( ± ) DOX ( 8. 68 ± 0. 17 ) , ( +) DOX ( 8. 48 ± 0. 10 ) , ( -) DOX ( 7. 48 ± 0. 140 ) . Conclusion The α1-adrenoceptor blocking activity of ( -) DOX is much weaker than that of ( +) DOX or ( ± ) DOX in the rat isolated mesenteric arterioles, and there is a tendency to enhance the activity of ( ± ) DOX in third-order branches of the rat mesenteric artery though theα1-adrenoceptor blockade effect of ( ± ) DOX is not significantly different from ( +) DOX.
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Objective To investigate the influence of autoantibodies against the second extracellular loop of β1-adrenoceptor ( β1-AA) on the proliferation ability of LPS-stimulated rat B lymphocytes.Methods Active immunization assay was used to obtain adequate IgGs in which β1-AA was positive; MACS (magnetic activated cell sorting) assay was used for gaining rat splenic B lymphocytes; CCK8 assay was used for detecting the influence of β1-AA to the proliferation abilities of silent and LPS-stimulated rat splenic B lymphocytes.Results β1-AA (0.1 μmol/L pIgGs ) promoted the proliferation of LPS-stimulated rat splenic B lymphocytes(A values:0.739±0.036 vs 0.533±0.032,P＜0.05),and the effect was likely to be concentration-dependent.And the effect could be blocked by β1-AR blocker or β2-AR blocker partially,and could be blocked by β1-AR blocker and β2-AR blocker completely; β1-AA had no proliferation effect on silent rat splenic B lymphocytes.Conclusion β1-AA could promote the proliferation of LPS-stimulated rat splenic B lymphocytes via β1-AR and β2-AR which were on the surface of B lymphocytes.Thus,it could provide new clues for complex pathologic mechanism of cardiovascular patients in which β1-AA is positive.
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OBJECTIVE To investigate the blocking activities of a series of potential α1-adrenoceptor (α1-AR) antagonists (Compounds B1 -B9) on α1-AR.METHODS ① A series of potential α1-adrenoceptor (α1-AR) antagonists,indolylpiperidine derivative (IPD) and Compounds B1 -B9,with indolylpiperidine moiety and different substitutes were synthesized through the coupling of indolylpiperidine and piperazine derivatives.② Inotropic responses experiment was used to examine blocking effects of IPD and Compounds B1 - B9 in isolated rat atria by phenylephrine (PE) stimulation.③ Blocking effect of IPD and Compounds B1 - B9 on phosphorylation level of extracellular signal-regulated kinase (ERK) in PE treated HEK293 cells was tested by Western blotting.RESULTS ① Potential α1-adrenoceptor (α1-AR) antagonists with indolylpiperidine moiety and different substitutes were synthesized successfully.② PE caused a dose-dependent inotropic response which was inhibited by pre-incubation of phentolamine (Phen),a non-selective α1-AR antagonist,IPD and Compounds B1,B3,B4,B7,B8 and B9,respectively; IPD and Compounds B4 and B8 caused an obvious rightward shift of inotropic response-curve,the pA2 values for IPD and Compounds B4 and B8 were 6.72 ± 0.21,6.86 ± 0.29 and 6.67 ± 0.19,respectively.③ Phosphorylation level of ERK1/2 was inhibited by pre-incubation with Compounds B1,B2,B3,B5,B6,B7,B8 and B9 or IPD in PE treated α1A-AR stably expressed HEK293 cells; PE-stimulated phosphorylation level of ERK1/2 was inhibited by pre-incubation with Compounds B2,B4,B7 or B8 in α1B-AR stably expressed HEK293 cells.CONCLUSION Compound B4 has a selective blocking activity on α1B-AR,and Compounds B1,B3,B5,B6 and B9 or IPD have a selective blocking activity on the phosphorylation level of ERK1/2.
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PURPOSE: The aim of this study was to assess the efficacy and safety of tamsulosin, 0.2mg/day on sexual function in Korean BPH patients. Patients and Methods: 116 patients (mean age: 60 yrs) with BPH were enrolled in this study and 0.2mg of tamsulosin was administrated every night for 3 months. Primary efficacy was evaluated with changes of IIEF and GEQ. Secondary efficacy parameters were changes of IPSS and QoL, uroflowmetry, changes of total IIEF and IIEF domain score according to the severity of IPSS, and retrograde ejaculation. RESULTS: Before treatment, patients of moderate IPSS (8-19) and severe IPSS (20-35) were 56% and 44% and QoL3 were 33.6% and 66.4%. In primary efficacy evaluation, total IIEF score was significantly increased from 37.0+/- 18.2 to 40.5+/- 18.9 (p<0.01). All domains of IIEF except orgasmic function were significantly improved. GEQ showed improvement of erection in 34.4% and intercourse ability in 30.1%. In secondary efficacy evaluation, IPSS was significantly decreased from 18.4+/- 6.9 to 12.9+/- 6.7 (p<0.01) and QoL was significantly improved from 3.8+/- 1.1 to 2.7+/- 1.4 (p<0.01). Qmax significantly increased from 14.2+/- 8.3 to 16.5+/- 11.3 ml/sec (p<0.01). Total IIEF score and EF domain score were significantly improved from 36.8+/- 18.5 to 41.8+/- 19.1 (p<0.01) and from 13.0+/- 7.1 to 14.7+/- 7.9 (p<0.01) in patients of moderate IPSS but no improvement in severe patients. Retrograde ejaculation occurred in 2 patients (2%). No serious adverse reactions were observed. CONCLUSIONS: Tamsulosin, 0.2mg/day was effective and safe dose for the improvement of LUTS and sexual function for Korean BPH/LUTS patients.
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Humans , Male , Ejaculation , Orgasm , Prospective Studies , SulfonamidesABSTRACT
Aim: To search for novel α_1-adrenoceptor(α_1-AR) antagonists. Methods: On the basis of hybridization principle with silodosin as the lead compound, twelve 5-[2-[4-[ ( substituted phenoxy) alkyl] piperazin-1-yl] propyl] indoline compounds were designed and synthesized by maintaining indoline while incorporating the 1-[(substituted phenoxy) alkyl] piperazine group. Results: The structures of synthesized target compounds were confirmed by the elemental analysis, IR, ESI-MS and ~1H NMR. Preliminary pharmacological test showed that pA_2 values of six target compounds were greater than 7. 50, which suggested that the compounds possessed considerable α_1-AR antagonic activity. Conclusion: 5-[2-[4-[ ( substituted phenoxy) alkyl] piperazin-1-yl] propyl] indoline compounds is potentially a new candidate for α_1-AR antagonist.
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PURPOSE: We evaluated the effectiveness of alpha 1 adrenoceptor antagonist tamsulosin on erectile function in the treatment of the patients with benign prostatic hyperplasia (BPH). MATERIALS AND METHODS: We recruited 268 patients who had BPH with lower urinary tract symptoms in the period of June 2003 to September 2003. The study utilized an open-label approach. Patients were evaluated by physical examination, transrectal ultrasonography (TRUS), serum prostate specific antigen (PSA), uroflowmetry, international prostatic symptom score (IPSS), quality of life (QOL) assessment, voiding diary for 3 days, brief international index of erectile function (IIEF)-7 score, and the global efficacy assessment questionnaire (GEAQ)-2. All evaluations were performed before medication, and again at 4 and 12 weeks of treatment. The patients suspected to have prostatic carcinoma based on the digital rectal examination and/or PSA level above 4 ng/ml underwent transrectal ultrasonography guided biopsy of the prostate. The patients found to have prostate cancer were not included in the study. RESULTS: A total of 165 patients completed the study. Total IIEF scores did not change significantly. Question 10 of IIEF was significantly different between 4 and 12 weeks. There was a statistically significant difference in GEAQ-2 between 4 and 12 weeks of medication. Ejaculation volume decreased 14% and 22% at 4 and 12 weeks, respectively. However, orgasmic function significantly improved between 4 and 12 weeks. CONCLUSIONS: In patients with BPH, tamsulosin therapy improved sexual and orgasmic function, although it decreased ejaculation volume. We need a longer follow-up period and more patients to establish the effects of tamsulosin on erectile function in the patients with BPH.
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Humans , Male , Biopsy , Digital Rectal Examination , Ejaculation , Follow-Up Studies , Lower Urinary Tract Symptoms , Orgasm , Physical Examination , Prostate , Prostate-Specific Antigen , Prostatic Hyperplasia , Prostatic Neoplasms , Quality of Life , Surveys and Questionnaires , UltrasonographyABSTRACT
Aim To investigate the relationship between spinal cord noradrenergic neurons ? 1 adrenoceptors and the spinal analgesia of ketamine. Methods Kunming mice were used. Analgesia tests were investigated with warm water tail flick test. The effects of intrathecal injection (ith) of ketamine (50,100,200 ?g)on tail flick latency of animals were observed. And the effect of pretreatment with intrathecal 6 hydrodoapa(6 OHDA, 6?g ) and ? 1 adrenoceptor antagonist prazosin (5, 15 ?g) or terazosin (5, 15 ?g) , respectively on the spinal analgesia of ketamine (100 ?g,ith) was studied. Results Dose dependent analgesia was observed following ith ketamine (100,200 ?g, P
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We investigated the adrenergic sensitivity of afferent fibers in the L4 dorsal roots of rats with a unilateral ligation of the L5-L6 spinal nerves. About 12% of nociceptive fibers on the affected side were excited by sympathetic stimulation or by intra-arterial injection of norepinephrine which did not affect A beta-fiber activity. Sympathetic excitation of nociceptive fibers was suppressed by alpha 1-antagonist prazosin, while it was unaffected by alpha 2-antagonist yohimbine. Most of these fibers were excited by intra-arterial injection of alpha 1-agonist phenylephrine, without being affected by an injection of alpha 2-agonist clonidine. Sympathetic excitation was blocked by lidocaine applied near the receptive fields of recorded fibers. The results suggested that some nociceptors remaining intact after partial nerve injury become sensitive to sympathetic activity by the mediation of alpha 1-adrenoceptors in the peripheral endings.
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Male , Rats , Animals , Nerve Fibers/physiology , Nociceptors/physiology , Norepinephrine/pharmacology , Pain/physiopathology , Rats, Sprague-Dawley , Receptors, Adrenergic, alpha-1/physiologyABSTRACT
Objective To present experience on the diagnosis and treatment of bladder outlet obstruction (BOO) caused by bladder neck fibrosis. Methods 30 cases of BOO caused by bladder neck fibrosis were studied. All the patients were treated by transurethral partial resection or incision of the cervix vesicae combined with alpha 1 adrenoceptor antagonists such as tamsulosin and terazosin or parazosin. Results Urination has been improved in all.The patients have been followed up for 3 to 30 months.On repeated uroflowmetry,the 30 patients showed the urine flow rates have been more than 15ml/s. IPSS scores was 5.3?1.7(25.4?4.2 preoperative) and quality of life scores was 1.4?0.6(4.1?0.8 preoperative).Fibroblast proliferation was noted in all the 30 and obvious chronic inflammation in 18. Conclusions Clinical symptoms, pressure rate measurement and cystoscopy are the reliable diagnostic methods.Transurethral partial resection or incision of cervix vesicae combined with alpha 1 adrenoceptor antagonists is effective.
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PURPOSE: The role of spinal alpha1 adrenoceptors in normal micturition reflex of rat has not been known clearly yet. The purpose of this study is to elucidate the role of alpha1 adrenoceptor both at the spinal and peripheral level in mediating the micturition reflex which is induced by bladder distension in normal anesthetized rat and to compare the effects of different alpha1 adrenoceptor antagonists against the micturition reflex. MATERIALS AND METHODS: Wtih eighty female Sprague-Dawley rats(200-250gm) anesthetized with urethane, continuous cystometry was done by infusion of saline at a rate of 0.5ml/min. The following drugs were injected into femoral artery(intraarterial, i.a.) and subarachnoid space(intrathecal, i.t.) at the level of L6-S1 spinal cord segment; phentolamine, prazosin, doxazosin and tamsulosin. Cystometric parameters were analyzed before and after the drug injections; basal pressure(BP), micturition pressure(MP), bladder capacity(BC), micturition volume(MV), frequency and residual volume(RV). RESULTS: After i.a. injections of prazosin, doxazosin and tamsulosin, MP was significantly decreased. Doxazosin(i.a.), markedly increased MV, BC and RV. MP was more inhibited by doxazosin than prazosin or tamsulosin injection intraarterially. After i.a. injection of phentolamine, decrease in MP and frequency but increase in MV and BC were noted. Phentolamine(i.t.) raised BP and abolished MR followed by overflow incontinence. Prazosin(i.t.) induced marked increases in MV. Tamsulosin(i.t.) caused significant decreases in frequency but increases in BC. CONCLUSIONS: At spinal level, antagonism of micturition reflex evoked by bladder distension was more prominent by phentolamine. Inhibition of micturition reflex with alpha1 adrenoceptor blockers were greater peripherally. With these results, it could be suggested that micturition reflex evoked by volume-induced bladder distension could be modulated through alpha1 adrenoceptors at both the spinal and peripheral level. In some selected cases, alpha1 adrenoceptor agonist or antagonist can be useful for the management of lower urinary tract dysfunction
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Animals , Female , Humans , Rats , Doxazosin , Negotiating , Phentolamine , Prazosin , Rats, Sprague-Dawley , Receptors, Adrenergic , Reflex , Spinal Cord , Urethane , Urinary Bladder , Urinary Tract , UrinationABSTRACT
We previously reported an identification of a 77-kDa GTP-binding protein that co-purified with the alpha 1-adrenoceptor following ternary complex formation. In the present paper, we report on the purification and characterization of this GTP-binding protein (termed G alpha h5) isolated from pig heart membranes. After solubilization of pig heart membranes with NaCl, G alpha h5 was purified by sequential chromatographies using DEAE-Cellulose, Q-Sepharose, and GTP-agarose columns. The protein displayed high-affinity GTP gamma S binding which is Mg(2+)-dependent and saturable. The relative order of affinity of nucleotide binding by G alpha h5 was GTP > GDP > ITP >> ATP > or = adenyl-5'-yl imidodiphosphate, which was similar to that observed for other heterotrimeric G-proteins involved in receptor signaling. Moreover, the G alpha h5 demonstrated transglutaminase (TGase) activity that was blocked either by EGTA or GTP gamma S. In support of these observations, the G alpha h5 was recognized by a specific antibody to G alpha h7 or TGase II, indicating a homology with G alpha h (TGase II) family. These results demonstrate that 77-kDa G alpha h5 from pig heart is an alpha 1-adrenoceptor-coupled G alpha h (TGase II) family which has species-specificity in molecular mass.
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Animals , Binding Sites , Binding, Competitive , Cross Reactions , GTP-Binding Proteins/metabolism , GTP-Binding Proteins/isolation & purification , GTP-Binding Proteins/immunology , Guanosine 5'-O-(3-Thiotriphosphate)/metabolism , Molecular Weight , Myocardium/chemistry , Transglutaminases/metabolism , Receptors, Adrenergic, alpha-1/metabolism , SwineABSTRACT
Tetrahydroisoquinoline (THI) alkaloids can be considered as cyclized derivatives of simple phenylethylamines, and many of them, especially with 6,7-disubstitution, demonstrate relatively high affinity for catecholamines. Two -OH groups at 6 and 7 positions are supposed to be essential to exert beta-receptor activities. However, it is not clear whether -OH at 6,7 substitution of THIs also shows alpha-adrenoceptor activities. In the present study, we investigated whether -OH or -OCH3 substitutions of 6,7 position of THIs differently affect the alpha1-adrenoceptor affinity. We synthesized two 1-naphthylmethyl THI alkaloids, 1-beta-naphthylmethyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline HBr (YS 51) and 1-beta-naphthylmethyl-6, 7-dimethoxy-1,2,3,4-tetrahydroisoquinoline HCl (YS 55), and their pharmacological actions on alpha1-adrenoceptor were compared. YS 51 and YS 55, concentration-dependently relaxed endothelium-denuded rat thoracic aorta precontracted with phenylephrine (PE, 0.1 micrometer) in which pEC50 were 5.89+0.21 and 5.93+ 0.19, respectively. Propranolol (30 nM) did not affect the relaxation-response curves to YS 51 and YS 55. Concentration-response curves to PE were shifted to right by the pretreatment with YS 51 or YS 55. The pA2 values of YS 51 and YS 55 showed 6.05 + 0.24 and 5.88 + 0.16, respectively. Both probes relaxed KCl (65.4 mM)-contacted aorta and inhibited CaCl2-induced contraction of PE-stimulated endothelium-denuded rat thoracic aorta in Ca2+-free solutions. In isolated guinea pig papillary muscle, 1 and 10 micrometer YS 51 increased contractile force about 4- and 8- fold over the control, respectively, along with the concentration-dependent increment of cytosolic Ca2+ ions. While, 10 micrometer YS 55 reduced the contractile force about 50 % over the control and lowered the cytosolic Ca2+ level, in rat brain homogenates, YS 51 and YS 55 displaced (3H)prazosin binding competitively with Ki 0.15 and 0.12 micrometer, respectively. However, both probes were ineffective on (3H)nitrendipine binding. Therefore, it is concluded that two synthetic naphthylmethyl-THI alkaloids have considerable affinity to alpha1-adrenenoceptors in rat aorta and brain.
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Animals , Rats , Alkaloids , Aorta , Aorta, Thoracic , Brain , Cardiovascular System , Catecholamines , Cytosol , Guinea Pigs , Ions , Papillary Muscles , Phenethylamines , Phenylephrine , PropranololABSTRACT
Mg2+ is the fourth most abundant cation in cellular organisms. Although the biological chemistry and the physiological roles of the magnesium ion were well known, the regulation of intracellular Mg2+ in mammalian cells is not fully understood. More recently, however, the mechanism of Mg2+ mobilization by hormonal stimulation has been investigated in hearts and in myocytes. In this work we have investigated the regulation mechanism responsible for the Mg2+ mobilization induced by alpha1-adrenoceptor stimulation in perfused guinea pig hearts or isolated myocytes. The Mg2+ content of the perfusate or the supernatant was measured by atomic absorbance spectrophotometry. The elimination of Mg2+ in the medium increased the force of contraction of right ventricular papillary muscles. Phenylephrine also enhanced the force of contraction in the presence of Mg2+/-free medium. alpha1-Agonists such as phenylephrine were found to induce Mg2+ efflux in both perfused hearts or myocytes. This was blocked by prazosin, a alpha1-adrenoceptor antagonist. Mg2+ efflux by phenylephrine was amplified by Na+ channel blockers, an increase in extracellular Ca2+ or a decrease in extracellular Na+. By contrast, the Mg2+ influx was induced by verapamil, nifedipine, ryanodine, lidocaine or tetrodotoxin in perfused hearts, but not in myocytes. W7, a Ca2+/calmodulin antagonist, completely blocked the phenylephrine-, A23187-, veratridine-, Ca2+/-induced Mg2+ efflux in perfused hearts or isolated myocytes. In addition, Mg2+ efflux was induced by W7 in myocytes but not in perfused heart. In conclusion, An increase in Mg2+ efflux by alpha1-adrenoceptor stimulation in hearts can be through IP3 and Ca2+/-calmodulin dependent mechanism.
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Animals , Chemistry , Guinea Pigs , Guinea , Heart , Lidocaine , Magnesium , Muscle Cells , Myocytes, Cardiac , Nifedipine , Papillary Muscles , Phenylephrine , Prazosin , Ryanodine , Spectrophotometry , Tetrodotoxin , VerapamilABSTRACT
AIM To investigate the roles of Cl- channels in Ca2+ influx induced by activaion of al- adrenoceptor subtypes in transfected-CHO cells. METHODS The effects of drugs on ?1A、?1B and ?1D- AR-induced Ca2+ influx were investigated with Fura2 fluorescence technique. RESULTS The ?1A-AR- induced Ca2+ influx was inhibited by furosemide(2 .5 ~ 10 M?mol?L- 1 )and SK&F96365(5- 15 ?mol?L- 1 ) in a concentration- dependent manner respectively; The ?1B-AR-induced Ca2+ influx could also be inhibit inhibited by NFA(2. 5 ~ 10 ?mol? L-1 ), whereas the alD AR-induced Ca2+ influx was only suppressed by NFA. In ?1B-CHO cells, Adr-triggered Ca2+ influx could be further inhibited by NFA or furosemide after the maximal inhibition by SK&F96365;SK&F96365 could further inhibit Ca2+ influx which had been inhibited by NFA or furosemide. In ?1A-CHO cells, Adr-triggered Ca2+ influx could be further inhibited by SK&F96365 after had been inhibited by furosemide; furosemide could not further inhibite Ca2+ influx which had been inhibited by S&F96365. CONCLUSION There are different characteristics of CI- channels related to ?1A、 ?1B and ?1D-AR-induced Ca2+ influx.
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Aim To determine the roles of peripheral ? 1 and ? 2 -adrenoceptors (? 1-AR,? 2-AR) in inhibition of carotid sinus barore ceptor reflex(CSR) induced by intracerebroventricular injection (icv) of histami ne (HA).Methods The left and right carotid sinus regions were i solated from the systemic circulation in 22 male Sprague-Dawley rats anesthetiz ed with pentobarbital sodium.The intracarotid sinus pressure (ISP) was altered in a stepwise ma nner in vivo.ISP-mean arterial pressure (MAP) relationship curve and its ch aracteristic parameters were constructed by fitting to the logistic function wit h five parameters.The changes in CSR performance induced by icv HA and the effec ts of pretreatment with ? 1-AR or ? 2-AR selective antagonist into the per ipheral vein on the responses of CSR to HA were examined.Results icv microinjection of HA (60 ?mol?L -1 in 5 ?l) significantly shifted the ISP-MAP relationship curve upwards (P0.05).Conclusion The intracerebroventricular administration of HA results in a rapid resetting of CSR and a decrease in reflex sensitivity, and the functions of both the peripheral ? 1-AR and ? 2-AR may attenuate CSR resetting induced by icv microinjection of HA. Furthermore,the peripheral ? 1-AR might play an important role in mediating the responses of CSR to central HA.
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Objective:To construct a human Fab phage antibody library and to obtain some recombinant clones which can express Fab fragment antibody against ? 1-adrenergic receptor.Methods:Fd heavy chain gene and ??? light chains gene of IgG obtained by RT-PCR from peripheral lymphocytes of DCM patients whose anti ? 1-AR antibodies are present were cloned into pComb3 vector and the human Fab phage antibody library was constructed.The library was panned by phage display technology with ? 1-ARECⅡ as antigen.Results:A human Fab phage antibody library with 1.4?10 6 capability was constructed successfully,a positive clone against human ? 1-AR was screened from the phage antibody library.Conclusion:The recombinant clones which express Fab antibody against ? 1-AR can be obtained by phage display technology.
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0.05). Pretreatment with intrathecal prazosin (30 ?g) significantly reduced the antinociception of ketamine 10 min after injection but not 10?g (P