N末端脑钠肽前体、超敏C反应蛋白、同型半胱氨酸在老年慢性心力衰竭患者中的临床意义

目的探讨N末端脑钠肽前体(NT-pro BNP)、超敏C反应蛋白(hs-CRP)、同型半胱氨酸(HCY)在老年慢性心力衰竭(CHF)患者中的临床意义及与左室射血分数(LVEF)的相关性。方法选取92例老年慢性心力衰竭患者作为观察组,52例健康老年人作为对照组。检测两组患者血清NT-pro BNP、hs-CRP、HCY水平,运用超声心动图进行左室射血分数测定,并进行相关性分析。结果心力衰竭组NT-pro BNP、hs-CRP、HCY水平较对照组显著升高,心力衰竭组LVEF较对照组显著降低,差异有统计学意义(P<0.01)。心力衰竭组随着NYHA分级的增加,NT-pro BNP、hs-CRP、HCY水平也逐渐升高,LVEF值下降,差异有统计学意义(P<0.05)。相关性分析提示NT-pro BNP、hs-CRP、HCY与LVEF呈负相关(r=-0.65、-0.24、-0.45,P<0.05)。结论血清NT-pro BNP、HCY、hs-CRP随着心力衰竭程度的加重而相应升高。

Role of calcium-activated potassium currents in CNP-induced relaxation of gastric antral circular smooth muscle in guinea pigs

AIM: To investigate ion channel mechanism in CNP-induced relaxation of gastric circular smooth muscle in guinea pigs.METHODS: Spontaneous contraction of gastric smooth muscle was recorded by a four -channel physiograph. The whole cell patch-clamp technique was used to record calciumactivated potassium currents and membrane potential in the gastric myocytes isolated by collagenase.RESULTS: C-type natriuretic peptide (CNP) markedly inhibited the spontaneous contraction in a dose-dependent manner in gastric circular smooth muscle in guinea pigs.Ly83583, an inhibitor of guanylate cyclase, weakened CNPinduced inhibition on spontaneous contraction but Zaparinast, an inhibitor of cGMP sensitive phosphoesterase,potentiated CNP-induced inhibition in gastric circular smooth muscles. The inhibitory effects of CNP on spontaneous contraction were blocked by tetrathylammonium (TEA), a nonselective potassium channel blocker. CNP hyperpolarized membrane potential from -60.0 mV±2.0 mV to -68.3 meV±3.0 mV in a single gastric myocyte. CNP increased calcium-activated potassium currents (Ik(ca)) in a dose-dependent manner in gastric circular myocytes. CNP also increased the spontaneously transient outward currents (STOCs). Ly83583 partly blocked CNP-induced increase of calcium-activated potassium currents, but Zaparinast potented the effect.CONCLUSION: CNP inhibits spontaneous contraction, and potassium channel may be involved in the process in gastric circular smooth musde of guinea pigs. CNP-induced increase of Ik(ca) is mediated by a cGMP dependent pathway.

重组腺病毒Ad-hBNP对慢性心衰大鼠心肌细胞凋亡因子及Ⅰ、Ⅲ型胶原表达的影响

目的观察外源基因人B型利钠肽对慢性心力衰竭大鼠心肌细胞凋亡因子及Ⅰ、Ⅲ型胶原表达的影响。方法 30只慢性心力衰竭模型大鼠,随机分为携带人B型利钠肽基因重组腺病毒组(Ad-hBNP组,14只)、重组空白腺病毒组(Ad-Track组,8只)、生理盐水组(NS组,8只),分别给予腹腔注射人B型利钠肽基因重组腺病毒、重组空白腺病毒及生理盐水1mL,每周1次,共4周。另设10只未造模但实行了假手术的大鼠为假手术组;4周后处死大鼠,行RT-PCR检测心肌组织Bcl-2、Bax、Caspase-3及Ⅰ、Ⅲ型胶原mRNA含量。结果 Ad-hBNP治疗后,Ad-hBNP组大鼠心肌组织Bcl-2mRNA表达较Ad-Track组及NS组升高;BaxmRNA表达较假手术组升高;Caspase-3mRNA表达较Ad-Track组、NS组及假手术组均升高。Ad-hBNP组Ⅰ、Ⅲ型胶原mRNA表达较Ad-Track组降低。结论间断给予Ad-hBNP能够影响慢性心力衰竭大鼠心肌细胞凋亡相关基因的表达,减少心肌细胞间质Ⅰ、Ⅲ型胶原的表达。

Comparative study in the effect of C-type natriuretic peptide on gastric motility in various animals

AIM: To investigate the effect of natriuretic peptides on gastric motility in various animals, and the effect of C-type natriuretic peptide (CNP) on spontaneous contraction of gastric smooth muscle in rat, guinea-pig and human in vitro was compared.METHODS: Spontaneous contraction of gastric smooth muscle was recorded by four channel physiograph.RESULTS: In the guinea-pig and rat gastric antral circular smooth muscle, CNP markedly decreased the amplitude of spontaneous contraction but it didn't affect the frequency,however, the contractile activity was completely inhibited by CNP in gastric antral longitudinal smooth muscle. In the human gastric antral circular and longitudinal smooth musie, CNP completely inhibited spontaneous contraction. In the circular smooth muscle of guinea-pig and rat gastric fundus,CNP obviously decreased the amplitude of spontaneous contraction but it didn't affect the frequency, however, the contractile activity was completely inhibited by CNP in smooth muscle of fundus longitudinal. In the circular and longitudinal smooth muscle of guinea-pig gastric body, CNP at first induced a relaxation and then an increase in amplitude of spontaneous contraction (rebound contraction), but the frequency was not changed. After the circular smooth muscle of gastric body was pretreated with atropine, an M receptor blocker, the rebound contraction was abolished; In circular and longitudinal smooth muscle of rat gastric body, CNP induced a transient and slight relaxation and successively followed by the recovery in amplitude of spontaneous contraction but it also didn't affect the frequency. After the smooth muscle was pretreated with atropine, the transient and slight relaxation was replaced by long term and complete inhibition; The percentage of CNP-induced inhibition was 76.77±6.21% (fundus), 67.21±5.32 % (body) and 58.23±6.21% (antral) in the gastric circular muscle, however, the inhibitory percentage was 100±0.00 % (fundus), 68.66±3.55 % (body) and 100±0.00 % (antrum) in the gastric longitudinal smooth muscle of guinea-pigs; In the rat, the percentage of CNP-induced inhibition was 95.87±4.12 %(fundus), 94.91±5.08 % (body) and 66.32±7.32 % (antrum)in the gastric circular smooth muscle, but in the longitudinal smooth muscle, CNP completely inhibited the spontaneous contraction. Using LY83583, a guanylate cyclase inhibitor, and zaparinast as a phosphoesterase inhibitor to inhibit the generation of cGMP, the effect of CNP on the spontaneous contraction was markedly weakened by LY83583, however, the inhibitory effect was enhanced by zaparinast.CONCLUSION: (1) CNP can obviously inhibit the spontaneous contraction of gastric antral circular and longitudinal smooth muscle in the rat, guinea-pig and human.The order of inhibitory potency is human ＞rat＞ guinea-pig.(2) In the same animals, the inhibitory effect of CNP on spontaneous contraction is the most powerful in fundus and the weakest in antrum, in the same position, the inhibitory effect on the circular smooth muscle is more powerful than that on longitudinal smooth muscle. (3) The inhibitory effect of CNP on spontaneous contraction in the gastric smooth muscle is mediated by a cGMP dependent pathway.