The effects of gutter oil on liver function,renal function and serum lipid metabolism in mice / 预防医学

Objective To determine the effects of gutter oil on liver function,renal function and serum lipid metabolism in mice.Methods A total of 72 mice were averagely divided into 6 groups.Mice were gavaged with different dosages (5 μL/g,1 0 μL/g and 20 μL/g)of gutter oil or cooking oil every other day for continuing 8 weeks.The indexes of liver, kidney and serum lipid parameters were assayed.Results The moisture,acid value and peroxide value of the gutter oil exceeded the national standard.After continuing 8 weeks'intake of oils,alanine aminotransferase (ALT)of gutter oil group with a dosage of 5 μL/g,as well as aspartate aminotransferase (AST)of gutter oil group with a dosage of 1 0 μL/g significantly increased (P <0.05),compared with the cooking oil group.Serum creatinine (Scr)of the gutter oil groups with 3 dosages significantly increased compared with the control groups (P <0.05 ).Meanwhile,blood urea nitrogen (BUN)of gutter oil groups with a dosage of 5 μL/g and 1 0 μL/g were also significantly increased respectively(P <0.05). However,no significant differences were observed in triglyceride (TG)and total cholesterol (TC)among the groups. Conclusion Eight weeks'intake of gutter oil could cause the damage to liver and renal functions.

Progress on matrix metalloproteinase in axonal regeneration / 浙江大学学报·医学版

Matrix metalloproteinases (MMPs) are zinc-dependent endopeptidases. MMPs can degrade and remodel extracellular matrix, also active or inactive many molecules attaching to matrix including receptors, growth factors and cytokines, so that injury-induced MMPs can change the extracellular environment to affect the axonal regeneration in central nervous system. In this review, with spinal cord injury (SCI) as an example we discuss the effects of MMPs on inflammation, neuronal viability, extracellular molecules, glial scar and axonal remyelination, which are all important to axonal regeneration.

LIM kinases and their roles in the nervous system / 浙江大学学报·医学版

LIM kinase-1 (LIMK1) and LIM kinase-2 (LIMK2) are kinases that have serine/threonine and tyrosine dual specificity. Although they show significant structural similarity, LIMK1 and LIMK2 have different expression patterns, subcellular localization, and functions. Activation of LIM kinases regulates the downstream of Rho GTPases, and influences the architecture of the actin cytoskeleton by regulating the activity of cofilin. Recent studies have shown that LIM kinases play important roles in the nervous system. For example, development of the central nervous system is reliant upon the presence of LIMK1, and deletion of Limk1 gene is involved in the development of the human genetic disorder Williams syndrome. Therefore, it is of vital physiological significance to investigate the neuronal function of LIM kinases. In this review, we outline the structure, phosphorylation regulation and neuronal function of LIM kinases, so as to provide new ideas for the treatment of these neurological diseases.

Comparison of mannitol and hypertonic saline in treatment of intracranial hypertension of rabbits / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To compare the effects of mannitol and hypertonic saline (HS) in treatment of intracranial hypertension (ICH) of rabbits.</p><p><b>METHODS</b>The animal mode of ICH was established by perfusing artificial cerebrospinal fluids (aCSF) with controlled pressure into the cerebral ventricles of rabbits. The mean arterial pressure, respiratory rate, tidal volume, perfusion rate of aCSF and water content of cerebrum were investigated in rabbits with ICH after a single bolus of 20% mannitol (5 ml/kg), 7.5% HS (2.2 ml/kg) or 23.4% HS (2.2 ml/kg).</p><p><b>RESULTS</b>After the intracranial pressure was elevated from 15 cmH₂O to 75 cmH₂O, the mean arterial pressure was increased and the tidal volume was decreased. After treatment by 20% mannitol, 7.5% HS or 23.4% HS, the increased percentage of mean arterial pressure and the decreased percentage of tidal volume were similar to the changes in control group. However, the perfusion rate of CSF was increased and water content of cerebrum was decreased after treatment by either 20% mannitol or 23.4% HS, but not by 7.5% HS. No different effects were found between 20% mannitol and 23.4% HS.</p><p><b>CONCLUSION</b>With the similar osmotic burden, 20% mannitol is more effective in treating ICH than 7.5% HS. With higher osmotic load, the efficacy of HS is enhanced, and 23.4% HS may be used as an alternative to mannitol in treatment of ICH.</p>

P21-activated kinases and their role in the nervous system / 生理学报

P21-activated kinases (PAK) participate in a variety of important cellular activities, such as cytoskeleton remodeling, cell migration, cell cycle regulation, and apoptosis or survival. PAK also has an important impact on brain development, neuronal differentiation, and regulation of synaptic plasticity in the nervous system. PAK abnormalities result in diseases including cancer, Parkinson's disease (PD), Alzheimer's disease (AD) and neural retardation. Therefore, it is of vital physiological significance to investigate the neuronal function of PAK. In this paper we review the advancement of research on the neuronal biological function and the underlying mechanisms of PAK.

Marrow mesenchymal stem cell transplantation with sodium alginate gel for repair of spinal cord injury in mice / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To investigate the effects of sodium alginate gels on marrow mesenchymal stem cell transplantation for repair of spinal cord injury (SCI) in mice.</p><p><b>METHODS</b>In the present study, effects of different sterilization methods and concentrations of sodium alginate gels were examined. Marrow mesenchymal stem cells (mMSCs) were isolated from mice and cultured. Cells were cultured with sodium alginate gels and MTT assay was applied to determine the cell viability. Mice spinal cord injury was induced by spinal cord transection. mMSCs were transplanted into the cavity of injured spinal cord with sodium alginate gels. The effects of sodium alginate gel were assessed by BMS scales and immunofluorescence staining for NF-200.</p><p><b>RESULTS</b>Compared with liquid form, solid form sodium alginate gel prepared with high pressure vapor sterilization had a better effect on cell viability. SCI mice treated with 10 % sodium alginate gel and mMSCs achieved higher score in BMS scale as well as higher expression of NF-200 compared with the untreated SCI group.</p><p><b>CONCLUSION</b>Sodium alginate gel prepared with solid form sterilization induces mMSCs proliferation and thus can be used as the carrier of stem cell in treatment of SCI.</p>

Negative inotropic effect of meperidine in rat ventricular muscle and the underlying mechanism / 生理学报

The purpose of the present study was to investigate the effect of meperidine on rat ventricular muscle. Cardiac function was assessed in Langendorff-perfused rat hearts and intracellular calcium level was recorded in enzymatically isolated rat ventricular myocytes using spectrofluorometric techniques. To explore the underlying mechanism, whole-cell configuration of patch-clamp technique was used to record L-type Ca(2+) current. The results showed that meperidine decreased the product of heart rate and left ventricular developed pressure (LVDP HR), maximal rate of the left ventricular pressure increase (LV +dP/dt(max)) and decrease (LV -dP/dt(max)), but increased left ventricular end-diastolic pressure in a dose-dependent manner (0-1000 micromol/L). Meperidine also produced a dose-dependent reduction in electrically induced [Ca(2+)](i) transient amplitude and an increase in diastolic [Ca(2+)](i) baseline level, but did not alter the caffeine (20 mmol/L) induced Ca(2+) release from intracellular ryanodine-sensitive Ca(2+) stores. Meperidine at 100 micromol/L inhibited L-type Ca(2+) current to 67.4 10.1% of control but did not affect the voltage dependency of activation and inactivation. The inhibitory effect of meperidine on Ca(2+) current could not be prevented by pretreatment with the opioid receptor antagonist naloxone. These data suggest that meperidine exerts a negative inotropic effect by inhibiting L-type Ca(2+) current. The lack of effect of naloxone implies that the action is independent of the opioid receptor.

Effects of pethidine on cardiac electrophysiological properties / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To investigate the effects of pethidine on electrophysiological properties of the isolated ventricular myocytes and the underlying mechanism.</p><p><b>METHODS</b>Langendorff was applied to perfuse rat heart model and whole-cell current clamp and voltage clamp techniques were used.</p><p><b>RESULTS</b>Pethidine decreased heart rate (HR) in a concentration dependent manner and caused severe atrioventricular block (AVB) at >or=250 micromol/L. Pethidine reduced action potential amplitude and maximal rate of depolarization, prolonged action potential duration. Pethidine at 100 micromol/L decreased sodium currents (I(Na)), transient outward potassium currents (I(to)), delayed rectifier potassium currents (I(k)) and L-type calcium currents (I(Ca.L)) to (60.7+/-6.9)%, (55.4+/-5.6)%, (65.1+/-8.0)% and (67.4+/-10.1)% of control levels,respectively. These effects could be recovered by washout. Naloxone, an opioid receptor antagonist, could not abolish the effects of pethidine on ionic currents.</p><p><b>CONCLUSION</b>Pethidine decreased HR and induced AVB, which may be related to the inhibition of I(Na), I(to), I(k) and I(Ca-L) of heart. The depression of cardiac currents is not mediated by opioid receptor.</p>

NO/cGMP signal pathway involved in the disturbance of calcium homeostasis in vascular smooth muscle during the late phase of sepsis / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To evaluate the alterations in calcium metabolism of the vascular smooth muscle of rat thoracic aorta in the late phase of sepsis and to investigate the involvement of nitric oxide (NO)/cyclic-GMP(cGMP) signal transduction pathway in the sepsis-induced vascular hyporeactivity.</p><p><b>METHODS</b>Male Sprague-Dawley rats were subjected to sepsis by cecal ligation and puncture (CLP). Eighteen hours post CLP, rat aortic rings were removed for measurement of contractile responses to vasoconstrictors by using organ bath technique.</p><p><b>RESULT</b>In endothelium intact aortic rings from CLP rats, concentration-contraction curves to phenylephrine (PE) and high KCl were significantly decreased when compared with those from control rats. The transient contraction induced by PE in calcium-free Krebs solution and the concentration-dependent contraction to CaCl(2)in KCl-depolarized medium were also markedly reduced. The hyporeactivity to vasoconstrictors was completely reversed by pretreatment either with aminoguanidine (AMG), a selective inducible nitric oxide synthase inhibitor, or with 1H [1,2,4] oxadiazolo[4,3-a] quininoxalin-1-one(ODQ), an inhibitor of NO-sensitive guanylyl cyclase.</p><p><b>CONCLUSION</b>A generalized impairment in calcium handling in vascular smooth muscle,including the calcium influx through the voltage-operated and receptor-operated channels and calcium release from intracellular calcium stores, is involved in vascular hyporeactivity during the late phase of sepsis. The NO/cGMP signal transduction pathway might be involved in this defect in vascular smooth muscle.</p>