A novel large animal model of recurrent migraine established by repeated administration of inflammatory soup into the dura mater of the rhesus monkey.

Several animal models of migraine have been established, and those based on trigeminovascular system activation are widely accepted. However, most of these models have been established on lower animals, such as rodents, and involve only a single administration of a noxious stimulus. In this study, an inflammatory soup (10 µL), consisting of prostaglandin E2 (0.2 mM), serotonin (2 mM), bradykinin (2 mM) and histamine (2 mM), was injected into the dura mater of conscious rhesus monkeys through an indwelling catheter. The infusion started on day 8 and was repeated every 3 days, for a total of six administrations, to induce neurogenic inflammation. We performed behavioral assessments and measured the expression of the oncogene c-fos, neuronal nitric oxide synthase (nNOS) and calcitonin gene related peptide (CGRP) in the trigeminal system and in multiple brain regions involved in pain processing by immunohistochemical staining. Compared with monkeys in the control group, three of the four animals in the inflammatory soup group displayed decreased motor behaviors, and two showed increased ipsilateral nose and mouth secretions during the stimulus period. Higher expression levels of c-fos, nNOS and CGRP were found in various brain areas of experimental animals compared with controls, including the trigeminal nucleus caudalis, thalamus, hypothalamus, midbrain, pons and other areas involved in pain perception. These results suggest that repeated inflammatory soup stimulation of the dura activates the trigeminovascular system and produces migraine-like pathological changes and abnormal behaviors in conscious rhesus monkeys.

[Toxicity of Caowu on in vitro cultured rat embryos].

OBJECTIVE: To study the developmental toxicity of Caowu and its mechanism on rat embryos. METHODS: Whole embryo culture was applied to test the effects of Caowu on rat embryos during the critical period of organogenesis. All embryos isolated on gestational day 9.5 were exposed to different concentrations of Caowu. The growth and differentiation of the embryos at the end of the 48 h culture period were observed. RESULTS: The embryonic growth and development were adversely affected by Caowu at the concentration of 2.5 mg/mL, which were represented as reduced yolk sac diameters, decreased number of somites, and lower morphological scores. With the increase of the concentrations of Caowu, more severe teratogenic effects appeared, including cardiac defect (undivided cardiac tube and inflated pericardial cavity), irregular somites, and brain malformation such as narrow brain vesicles. CONCLUSION: Caowu has direct embryotoxic effects on rats during the organogenesis period. We suggest that pregnant women in the first trimester use Caowu with cautions before a conclusion has been made.

[Effects of ErbB signal and protein kinase B on monkey cardiocyte apoptosis induced by rapid pacing].

This study is to investigate the roles of neuregulin receptor ErbB2 and protein kinase B (PKB) in pacing-induced heart failure of rhesus monkey. Rapid pacing was used to induce heart failure in rhesus monkey. Aorta intubatton was used to perform hemodynamic measurements, 17 days after pacing. N-Terminal pro-brain natriuretic peptide (BNP), one of the most important molecular marker of heart failure, was also measured by the method of electrochemical luminescence immunoassay. The mRNA expressions of ErbB2, PKB and Bcl-xl were detected in the left ventricular free walls by RT-PCR method. The expressions of phospho-PKB and Bcl-xl on protein level were also detected by Western blotting. The contractibility of cardiac muscle decreased significantly, which consisted with the increase of BNP. Compared with control group, the mRNA expressions of ErbB2, PKB and Bcl-xl were depressed, and similar results were also found in the protein expression analysis of phospho-PKB and Bcl-xl. The expressions of ErbB2, PKB and Bcl-xl were down-regulated during heart failure in rhesus monkey which suggested the important roles of ErbB2 receptor and PKB in the mechanism of heart failure.

[Effects of recombined human neuregulin on the contractibility of cardiac muscles of rhesus monkeys with pacing-induced heart failure].

OBJECTIVE: To evaluate the effects of recombined human Neuregulin on the contractibility of cardiac muscles of Rhesus Monkeys with pacing-induced heart failure and to reveal the possible mechanisms involved. METHODS: Twenty four rhesus monkeys were randomly divided into three groups (shame operated group, heart failure group and Neuregulin treated group), each with 8 monkeys. Heart failures were induced by rapid pacing (240 heartbeats/min). Daily intravenous injection of recombined human Neuregulin [3 microg/(kg x d)] and medical salt fluid were given to the monkeys for 10 days for the Neuregulin treated group and heart failure group respectively. Hemodynamic measurements such as peak positive rate of change in left ventricular blood pressure (+dP/dtmax) and left ventricular systolic, and end-diastolic blood pressures (LVSP and LVEDP) were compared between groups. The real-time quantitative RT-PCR was undertaken to detect the expression of myosin heavy chain mRNA in the left ventricular cardiac muscle. RESULTS: The monkeys in the heart failure group had lower levels of +dP/dtmax and LVSP and higher levels of LVEDP than those in the shame operated group (P < 0.05). The monkeys in the Neuregulin treated group had higher levels of + dP/dtmax than those in the heart failure group (P < 0.05). Lower expression of alpha-myosin heavy chain mRNA in the heart failure group was found compared with the shame operated group and Neuregulin treated group (P < 0.05). CONCLUSION: Recombined human Neuregulin can enhance the contractibility of cardiac muscles and relieve heart failure syndrome through reversing the falling of alpha-myosin heavy chain induced by rapid ventricular pacing.

Diffusion tensor MRI for the assessment of cerebral ischemia/reperfusion injury in the penumbra of non-human primate stroke model.

OBJECTIVES: The purpose of this study is to use diffusion tensor imaging (DTI) parameters to evaluate cerebral ischemia/reperfusion injury in the infarct core (IC) and ischemic penumbra (IP) in a rhesus transient middle cerebral artery occlusion (MCAO) model. METHODS: Seven rhesus monkeys were used to construct the MCAO model. The temporal evolution of the relative apparent diffusion coefficient (rADC) and the relative fractional anisotropy (rFA) in the IC area, infarct growth area (IG), and reversible penumbra area (RP) were investigated. RESULTS: The rADC increased in the three areas in the early stage of reperfusion (1 hour after the reperfusion). However, the rate of rADC improvement was significantly slower in IG than in IC and RP. Different temporal evolutions of rFA were observed in the three areas in the following stage of reperfusion (3-24 hours after the reperfusion), which continued to decline in IG but slightly elevated in IC and RP. DISCUSSION: These findings suggest that the evolution of DTI parameters can help in the assessment of cerebral ischemia/reperfusion injury in the penumbra and predict the growth of the infarction area after stroke.