The effects of ACEI on calpain-mediated cardiomyocytes apoptosis and cardiac function in diabetic rats / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To investigate the effects of angiotensin converting enzyme inhibitor (ACEI) captopril on Calpain-mediated cardiomyocytes apoptosis and cardiac function in diabetic rats.</p><p><b>METHODS</b>Thirty adult male SD rats were randomly divided into 3 groups (n = 10), normal control group (NC group), diabetes mellitus group (DM group)and captopril treated group (Cap group). Streptozocin (STZ) were used to make the model of diabetes mellitus, captopril was administrated by gavage at the dose of 50 mg/kg every day, while in NC group and DM group the same volume of normal saline was administrated. Twelve weeks later, left ventricular systolic pressure (LVSP), left ventricular end-diastolic pressure (LVDEP), maximal rise rate of left ventricular pressure (+ dp/dtmax) and maximal fall rate of left ventricular pressure (- dp/dtmax) were detected; Western blot was used to detect the expression of Calpain-1 Calpain-2, Bcl-2, Bax and total Caspase3 protein; apoptosis index (AI) were assessed by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL).</p><p><b>RESULTS</b>Compared with NC group, LVDEP was significantly higher; LVSP, + dp/dtmax and - dp/dtmax were significantly decreased (P < 0.05); Bcl-2 protein expression was decreased; the expression of Calpain-1, Calpain-2, Bax and total Caspase3 protein were increased; the value of AI was significantly increased. Compared with DM group, LVDEP was significantly lower; LVSP, + dp/dtmax and - dp/dtmax were significantly increased (P < 0.05); Bcl-2 protein expression was increased, the expression of Calpain-1, Calpain-2, Bax and total Caspase3 protein were decreased; the value of AI was significantly decreased (P < 0.05).</p><p><b>CONCLUSION</b>Captopril can protect diabetic myocardial structure through inhibiting activation of Calpain-1 and Calpain-2, up-regulating the expression of Bcl-2, down-regulating the expression of Bax to inhibit Caspase3 dependent apoptosis, thereby improving the ventricular function and myocardial structure.</p>

Neonatal fluoxetine exposure induced depression-like behaviors in adult Kunming mice and the antidepressant-like effect of agmatine / 药学学报

This study is to explore a behavioral and pathological model for depression in mice, and evaluate the anti-depressant-like effect of agmatine. Neonatal Kunming mice were treated with fluoxetine (10 mg x kg(-1), ip, qd) for 17 d (between day 4 and 21 after birth), and then the mice were normally housed till being adult (about 10 weeks after birth). The behaviors of the mice were measured by using open-field test, novelty suppressed feeding test and tail-suspension test. Hippocampal adenylate cyclase (AC) activity was measured by radioimmunoassay. Neonatal exposure to fluoxetine induced a "depression-like" behaviors in the adult mice, shown as the decreased locomotor activity, increased feeding latency and immobility time in the open-field test, novelty suppressed feeding test, and tail-suspension test, respectively. Chronic agmatine treatment (10 mg x kg(-1), ig, bid) for 3 weeks significantly increased the locomotor activity, and decreased the feeding latency in the neonatal fluoxetine exposed mice. Furthermore, single treatment with agmatine (40 mg x kg(-1), ig) also decreased the immobility time in the tail-suspension test, and increased the hippocampal AC activity in the mice. These results indicate that neonatal exposure to fluoxetine induces depressive-like behaviors in the adult mice. Agmatine reverses these behaviors, which may be closely related to the enhancement of the hippocampal AC activity.

5-HT1A/1B receptors, alpha2-adrenoceptors and the post-receptor adenylate cyclase activation in the mice brain are involved in the antidepressant-like action of agmatine / 药学学报

This study is to explore the possible mechanisms of the antidepressant-like effect of agmatine. By using two traditional "behavior despair" model, tail suspension test and forced swimming test, we examined the effects of some monoamine receptor antagonists (including beta-adrenergic receptor antagonist propranolol, beta-adrenergic receptor antagonist/5-HT1A/1B receptor antagonist pindolol, alpha2-adrenergic receptor antagonists yohimbine and idazoxan and 5-HT3 receptor antagonist tropisetron) on the antidepressant-like action of agmatine in mice. Activity of adenylate cyclase (AC) in the synapse membrane from rat frontal cortex was determined by radioimmunoassay. Single dose of agmatine (5-40 mg x kg(-1), ig) dose-dependently decrease the immobility time in tail suspension test in mice, indicating an antidepressant-like effect. The effect of agmatine (40 mg x kg(-1), ig) was antagonized by co-administration of beta-adrenergic receptor antagonist/5-HT1A/1B receptor antagonist pindolol (20 mg x kg(-1), ip), alpha2-adrenergic receptor antagonists yohimbine (5-10 mg x kg(-1), ip) or idazoxan (4 mg x kg(-1), ip), but not beta-adrenergic receptor antagonist propranolol (5-20 mg x kg(-1), ip) and 5-HT3 receptor antagonist tropisetron (5-40 mg x kg(-1), ip). Agmatine (5-40 mg x kg(-1), ig) also dose-dependently decrease the immobility time in forced swimming test in mice. The effect of agmatine (40 mg x kg(-1), ig) was also antagonized by pindolol (20 mg x kg(-1), ip), yohimbine (5-10 mg x kg(-1), ip), or idazoxan (4 mg x kg(-1), ip). Incubation of agmatine (0.1-6.4 micromol x L(-1)) with the synaptic membrane extracted from rat frontal cortex activated the AC in a dose-dependent manner in vitro. While the effect of agmatine (6.4 micromol x L(-1)) was dose-dependently antagonized by pindolol (1 micromol x L(-1)) or yohimbine (0.25-1 micromol x L(-1)). Chronic treatment with agmatine (10 mg x kg(-1), ig, bid, 2 w) or fluoxetine (10 mg x kg(-1), ig, bid, 2 w) increased the basic activity, as well as the Gpp (NH)p (1-100 micromol x L(-1)) stimulated AC activity in rat prefrontal cortex. These results indicate that regulation on 5-HT1A/1B and alpha2 receptors, and activation AC in the frontal cortex is one of the important mechanisms involving in agmatine's antidepressant-like action.