家兔主动脉中膜内、外层SMC超微结构比较研究

用网格交点计数法测量了正常家兔主动脉弓靠近内弹性膜和靠近外弹性膜侧的平滑肌细胞胞质的超微结构。主动脉弓靠内弹性膜侧的平滑肌细胞与靠外弹性膜侧的平滑肌细胞相比，两者的肌丝没有明显的变化，但前者胞质的粗面内质网、线粒体和高尔基复合体明显增多。结果提示：主动脉弓靠内弹性膜侧平滑肌细胞与合成功能相关细胞器增加可能与动脉粥样硬化的发生发展有关。     

Mg~(2+)和Ca~(2+)对兔心脏腺苷酸环化酶的调节作用

本文用氧化铝层析分离、纯化cAMP测定腺苷酸环化酶(AC)活性的方法,观察了Mg~(2+)和Ca~(2+)对兔心肌质膜AC的影响。结果Mg~(2+)激活AC,其Ka为2.5mM。Ca~(2+)抑制AC,其Ki为30μM。Ca~(2+)和Mg~(2+)对兔心肌质膜AC的调节是兢争的。     

COMPARISON OF THE ATTENUATING EFFECTS OF FOUR β-ADRENOCEPTOR AGONISTS ON RAT ISOLATED UTERUS AND AORTA

1. The ability of four 8-adrenoceptor agonists to attenuate oxytocin (0.2,2 and 20 nmol/L) or KCI (20,40 and 80 mmol/L)-induced Contractions of the uterus (n= 5–8 for each agonist) and the KCI (18 mmol/L)-induced contractions of the aorta (n = 9 for each agonist) from rats, pretreated with oestradiol has been compared. 2. Isoprenaline, salbutamol, terbutaline and procaterol (0.1–10μmol/L) attenuated the contractions of the uterus and the aorta. All four agonists had similar attenuating potencies on the uterus. 3. Procaterol caused the same maximal attenuation (33%) on the aorta as the other β-adrenoceptor agonists and is thus acting as a full β₂-adrenoceptor agonist under these experimental conditions. Isoprenaline and procaterol were much more potent than salbutamol and terbutaline in attenuating the aorta responses. 4. This study showed that isoprenaline and procaterol were potent attenuants on both the uterus and aorta whereas salbutamol and terbutaline were potent uterine but only modest aorta attenuants. This preliminary study indicates that the responsiveness of uterine and vascular tissue to certain β₂-adrenoceptors differs.     

Concurrent changes in intracranial pressure,cerebral blood flow velocity,and brain energy metabolism in rabbits with acute intracranial hypertension

The relationship between intracranial pressure or cerebral perfusion pressure (CPP), cerebral blood flow, and brain energy failure is unpredictable throughout the development of acute intracranial hypertension. The purpose of the present study was to correlate intracranial pressure with cerebral blood flow velocities and brain energy metabolism in adult rabbits. The acute intracranial hypertension was achieved by pressure transmission. Transcranial Doppler waveforms were obtained from the basilar artery for monitoring cerebral blood flow velocities. ³¹P-Magnetic resonance spectroscopy was used to assess brain energy metabolism. The diastolic blood flow velocity began to decrease significantly (34.5%) when the intracranial pressure was equal to half the diastolic arterial pressure for a CPP of 36±18 mmHg. Circulatory cerebral resistances increased significantly (55%) for the same value of CPP. Diastolic frequency was near zero when intracranial pressure approached diastolic arterial pressure (51±12 mmHg), corresponding to a CPP of 30±15 mmHg. At the same time, only a tendency for brain energy metabolism to decrease was observed. Consequently, transcranial Doppler sonography could be proposed for the followup of intracranial hypertension. Magnetic resonance spectroscopy could help to monitor these patients and could be especially proposed in case of high intracranial pressure (near diastolic arterial pressure). The joint ue of these two methods would help in making appropriate therapeutic decision in humans.     

酒醋溶液与吡佛拉唑溶液治疗兔皮肤真菌病的实验观察

本文报告酒醋溶液与１％吡佛拉唑溶液治疗兔皮肤真菌病的效果。实验结果表明，酒醋溶液对红色毛癣菌和石膏样毛癣菌均有效，与吡佛拉唑溶液疗效相似，与对照区有明显差别。无副作用。     

Divergent effects of deep cerebellar lesions on two different conditioned somatomotor responses in rabbits

Rabbits with bilateral lesions involving either the anterior interpositus nucleus or the superior cerebellar peduncle were subjected to appetitive Pavlovian conditioning training involving repeated pairings of a 2-s tone with an intraoral pulse of water. Such training resulted in the rapid development of robust, anticipatory jaw-movement responses (JM CRs) to the tone, and, in fact, the performance levels exhibited by lesioned animals did not differ significantly from those observed in sham-operated control animals. Additional experiments involving unpaired tone/water presentations confirmed the associative character of the JM CRs. On the other hand, lesioned animals exhibited severe bilateral performance deficits when later subjected to aversive eyeblink conditioning procedures, consistent with previous findings. The present results thus suggest that the interpositus nucleus is not an essential neural substrate for the development of appetitively conditioned masticatory responses.     

Graded postischemic reoxygenation reduces lipid peroxidation and reperfusion injury in the rabbit spinal cord

The effect of graded postischemic reoxygenation on lipid peroxidation, neurological recovery and the degree of spinal cord damage after 20 min abdominal aorta ligature was tested in the rabbit. In comparison with normoxic recirculation, the graded postischemic reoxygenation (GPIR) during early phase of reperfusion (30 min) significantly reduced the level of lipid peroxidation products (LPP) in vivo and in vitro after 1 h survival. Neuropathological changes in animals with normoxic reperfusion showed gradual deterioration ranging from appearance of heavy argyrophilic neurons after 1 h reperfusion followed by neuronal necroses after 12 h survival to the development of an extensive spongy lesion reaching ventral horn and intermediate zone 2 days postoperatively. The neuroprotective effect of graded postischemic reoxygenation was evident even after 2 days survival with preserved structural integrity of the gray matter as confirmed by light and electron microscopy. The results indicate that graded postischemic reoxygenation during 1 h reperfusion can reduce lipid peroxidation and suppress irreversible neuronal damage using developing during the early reperfusion phase.     

花生四烯酸、二十碳五烯酸及二十二碳六烯酸对兔主动脉条张力的影响

外源性AA引起兔动脉条收缩,呈剂量依赖性;EPA抑制AA收缩血管亦呈浓度依赖性;DHA对AA收缩血管作用无明显影响。破坏血管内皮后AA收缩血管作用大为减弱,EPA抑制AA收缩血管作用也几乎消失。吲哚美辛能阻断AA收缩兔主动脉条的作用。兔主动脉6-keto-PGF_1α、TXB₂及其比值随AA浓度升高而增加,低剂量EPA对前列腺素类代谢无明显影响,较大剂量时则降低上述指标。     

兔肝VX2肿瘤移植模型的复制及其意义

目的：探讨建立兔肝VX2肿瘤模型，为该模型的应用提供实验依据。方法：采用VX2细胞株复制兔肝肿瘤模型，并改进其制作方法，观察其肿瘤的生长过程，并检测肝功能谷丙转氨酶(ALT)、谷草转氨酶(AST)及总胆红素(TB)在模型制作前、后不同时相的变化，同时观察脏器转移、组织病理学改变、影像学表现及实验动物的自然生存时间。结果：接种后3周均可见到肿瘤生长，肿瘤直径为1．5～2．0cm左右，肿瘤接种成功率为100％；彩超检查显示肝脏有结节样增强回声，CT示肿瘤为低密度病灶，增强扫描见病灶不均匀强化。移植肿瘤外观呈灰白色，扪之质地较硬，无明显的包膜，剖开肿瘤中心可见灶性坏死；光镜下见肿瘤细胞核浆比例大，细胞排列紊乱，呈浸润性生长；动物接种后的自然生存时间为40～53d，死亡原因主要为肿瘤生长及转移引起的多脏器功能衰竭。结论：兔肝VX2肿瘤从病理表现、病理过程及转移均与人肝癌相似，该模型具有容易复制、生长周期短、成功率高及模型稳定等特点，是一种较理想的肝肿瘤实验动物模型。