降钙素基因相关肽诱导藻酸钙凝胶复合脂肪干细胞的成骨细胞分化

背景：降钙素基因相关肽已被证实具有诱导成骨细胞分化作用,但其是否可使三维培养下的脂肪干细胞向成骨细胞分化构建组织工程骨的相关报道少见。
　　目的：探讨外源性降钙素基因相关肽诱导兔脂肪干细胞复合藻酸钙凝胶三维培养成骨分化的可行性。
　　方法：取新西兰兔双侧腹股沟区皮下脂肪垫,Ⅰ型胶原酶消化离心贴壁法分离培养脂肪干细胞,取第3代与海藻酸钠混合制备凝胶,于24孔板分组培养：对照组加入含10-2 mol/Lβ-甘油磷酸钠、10-7 mol/L地塞米松、50 mg/L抗坏血酸、体积分数10%胎牛血清的DMEM/F-12骨诱导培养基,实验组在此基础上再加入1.5μg/L降钙素基因相关肽进行诱导培养。于诱导不同时间点MTT法检测细胞增殖,RT-PCR法检测诱导细胞Ⅰ型胶原和骨钙素mRNA的表达,并检测碱性磷酸酶及钙离子浓度。
　　结果与结论：兔脂肪干细胞的增殖曲线呈“S”型,实验组诱导1,3,5,7,14,21 d 的 A 值高于对照组(P<0.05);诱导2周后两组细胞碱性磷酸酶、茜素红染色均阳性,但实验组钙结节较对照组明显增多。实验组诱导7,14 d的Ⅰ型胶原和骨钙素mRNA表达均强于对照组。实验组诱导1,2,3,4周的碱性磷酸酶活性及钙离子浓度均高于对照组(P<0.05)。结果表明降钙素基因相关肽能诱导复合藻酸钙凝胶的脂肪干细胞向成骨细胞分化。     

Calcitonin gene-related peptide and somatostatin releases correlated with the area under the lafutidine concentration-time curve in human plasma

OBJECTIVE: To examine the effects of the histamine H(2)-receptor antagonist, lafutidine, at clinical dosage (10 mg tablet after a standardized meal) on plasma levels of the gastrointestinal peptides, calcitonin gene-related peptide (CGRP), somatostatin and gastrin. METHODS: Six healthy male volunteers ate a standardized meal, and received either lafutidine orally at a dose of 10 mg or water only (control). Blood samples were taken before and up to 4 h after the drug administration. Plasma lafutidine concentrations were determined by high pressure liquid chromatography. Pharmacokinetic analysis of lafutidine was performed using one-compartmental model. The levels of immunoreactive substances of plasma CGRP, somatostatin and gastrin were measured by enzyme immunoassay, and the amount of peptide release was calculated by the trapezoidal method. Lafutidine significantly increased plasma CGRP levels at 1, 1.5, 2.5 and 4 h and the total amount of CGRP release (192 +/- 14.0 pg.h/mL) compared with the control group (128 +/- 21.5 pg.h/mL). RESULTS: Lafutidine significantly increased the plasma somatostatin levels at 1 and 1.5 h, and the total amount of somatostatin released (107 +/- 18.2 pg.h/mL) compared with the control (78.4 +/- 7.70 pg.h/mL). The area under the drug concentration-time curve (AUC) from 0 to 4 h after administration correlated well with the Delta-CGRP and Delta-somatostatin release but not with total amount of gastrin released. However, plasma gastrin levels were significantly elevated at 1.5 h after drug administration. CONCLUSION: Lafutidine at clinical dosage increases plasma CGRP and the somatostatin. The amounts released correlated with the AUC of lafutidine in humans. These results suggest that the increased release of CGRP and somatostatin may contribute to its gastroprotective and anti-acid secretory effect.     

Involvement of calcitonin gene-related peptide in migraine: regional cerebral blood flow and blood flow velocity in migraine patients

Calcitonin gene-related peptide (CGRP)-containing nerves are closely associated with cranial blood vessels. CGRP is the most potent vasodilator known in isolated cerebral blood vessels. CGRP can induce migraine attacks, and two selective CGRP receptor antagonists are effective in the treatment of migraine attacks. It is therefore important to investigate its mechanism of action in patients with migraine. We here investigate the effects of intravenous human alpha-CGRP (halphaCGRP) on intracranial hemodynamics. In a double-blind, cross-over study, the effect of intravenous infusion of halphaCGRP (2 mug/min) or placebo for 20 min was studied in 12 patients with migraine without aura outside attacks. Xenon-133 inhalation SPECT-determined regional cerebral blood flow (rCBF) and transcranial Doppler (TCD)-determined blood velocity (V (mean)) in the middle cerebral artery (MCA), as well as the heart rate and blood pressure, were the outcome parameters. No change of rCBF was observed at the end of infusion [1.2% +/- 1.7 with halphaCGRP, vs. -1.6% +/- 3.1 with placebo (mean +/- SD)] (P = 0.43). V (mean) in MCA decreased to 13.5% +/- 3.6 with halphaCGRP versus 0.6% +/- 1.8 with placebo (P < 0.005). Since rCBF was unchanged, this indicates a dilation of the MCA. halphaCGRP induced a decrease in MAP (12%) (P < 0.005) and an increase in heart rate (58%) (P < 0.0001). CGRP dilates cerebral arteries, but the effect is so small that it is unlikely to be the only mechanism of CGRP-induced migraine.     

Demonstration of neuropeptide containing nerves and vasomotor responses to perivascular peptides in human cerebral arteries

A rich supply of nerve fibers containing neuropeptide Y-like (NPY-LI) and tyrosine hydroxylase-like immunoreactivity was seen in human cerebral arteries, arterioles and veins. Only a sparse supply of vasoactive intestinal polypeptide (VIP-LI), substance P (SP-LI), and calcitonin gene-related peptide (CGRP-LI) was demonstrated in the walls of human cerebral vessels. In isolated ring segments of human cerebral arteries, NPY and noradrenaline caused vasoconstriction but did not potentiate each other. VIP, peptide histidine methionine, SP, neurokinin A, and CGRP relaxed arteries precontracted by prostaglandin F_2a. The degree of innervation and the vasomotor responses are discussed in relation to migraine pathophysiology.     

头穴透刺结合康复训练对急性脑出血患者ET和CGRP的影响

目的 探讨头穴透刺结合康复训练对急性脑出血患者血浆内皮素（ET）和降钙素基因相关肽（CGRP）含量的影响.方法 90例急性脑出血患者随机分为头穴透刺结合康复训练组（A组）、康复组（B组）、西药对照组（C组）各30例,采用放射免疫分析法测定患者治疗前后血浆ET和CGRP含量的变化.结果治疗后,3组患者的血浆ET和CGRP含量均明显降低（ P＜0.01）,且A组、B组与C组比较有非常显著性差异（ P〈0.01）,A组和B组比较亦有非常显著性差异（ P〈0.01）.结论头穴透刺结合康复训练能调节血浆中ET和CGRP的含量,使其趋于动态平衡.     

Calcitonin gene-related peptide enhances CREB phosphorylation and attenuates tau protein phosphorylation in rat brain during focal cerebral ischemia/reperfusion

Calcitonin gene-related peptide (CGRP) is a potent vasodilator and immune cell modulator. Exogenous CGRP could increase the cerebral blood flow significantly and protect the ischemic neurons, but its mechanism is not entirely clear. The effect of CGRP on the expressions of CREB and tau in the ipsilateral parietal cortex were detected in focal cerebral ischemia/reperfusion model. The expression of CREB mRNA decreased in ischemia/reperfusion group (I/R group) compared with that of the sham operation group, and it got highest in CGRP group. CREB expression was lesser in I/R group than sham group, but it became more in CGRP group than I/R group. Phospho-CREB became more in I/R group, and it got most in CGRP group in the cortex. No significant difference was observed on Tau mRNA expression in all the groups. The level of tau hyperphosphorylation at Ser199/202 site and total tau in rat parietal cortex were significantly higher in I/R group than sham group. CGRP significantly inhibited tau hyperphosphorylation and the level of total tau also significantly reduced in CGRP group than that in I/R group. CGRP can upregulate the expression of CREB and phospho-CREB and attenuate the level of tau hyperphosphorylation in the ischemic neurons of the parietal cortex during focal cerebral ischemia/reperfusion. Phosphorylating CREB and inhibiting tau phosphorylation are probably involved in the mechanism of protective effect of CGRP to ischemic neurons.