A comparison of glue and a tube as an anastomotic agent to repair the divided buccal branch of the rat facial nerve

The best anastomotic agent to join nerve ends is controversial. This paper describes a controlled trial between a collagen tube wrap and a tissue glue to anastomose the rat facial nerve. There was no difference in the results using photographic, histological and electrophysiological techniques.     

Effects of Pyridoxalated Hemoglobin Polyoxyethylene Conjugate and Stroma-free Hemoglobin on Renal Vascular Responsiveness to Vasoactive Substances in Isolated Perfused Rat Kidney

Abstract: The effects of pyridoxalated hemoglobin polyoxyethylene conjugate (PHP) and stroma-free hemoglobin (SFH) on vascular responsiveness to various vasoactive substances were examined in isolated perfused rat kidneys. The kidneys isolated from rats were perfused with 6% PHP, 6% SFH, and 6% hydroxyethylstarch (HES) solution at a constant flow rate. Vascular responsiveness to acetylcholine (ACh), nitroglycerin (NG), norepinephrine (NE), and angiotensin-II (ANG-II) was examined by measuring the perfusion pressure (PP). Effects of inhibition of endothelium-derived relaxing factor (EDRF) by N^G-monomethyl L-arginine (L-NMMA) on NE-induced and ANG-II-induced renal vascular responses were examined. ACh and NG induced a dose-dependent decrease in perfusion pressure (PP) in all groups. NE and ANG-II induced an increase in PP in all groups, but NE-induced and ANG-II-induced responses in the PHP-perfused and SFH-perfused groups were significantly larger than those in the HES-perfused group. L-NMMA did not alter vascular responsiveness to NE and ANG-II. These results indicate that PHP and SFH do not inhibit EDRF induced by ACh, but hemoglobin moiety per se does augment the vascular responsiveness to NE and ANG-II in the isolated perfused rat kidney.     

Effect of temperature in focal ischemia of rat brain studied by 31P and 1H spectroscopic imaging

³¹P, ¹H and lactate spectroscopic imaging was used to evaluate the effects of hypothermia on focal cerebral ischemia produced by middle cerebral artery occlusion. The effects on high energy phosphate metabolism, pH, lactate and NAA were investigated in 24 spontaneously hypertensive rats subjected to either permanent or transient ischemia. Under either normothermic (37.5°C) or hypothermic (32°C) conditions, with permanent 6-h occlusion, there was little difference between groups in either the NMR measurements or the volume of infarction. In animals that underwent 3 h of ischemia followed by 12 h of reperfusion, the ischemic changes in lactate, pH, NAA, and high-energy phosphate returned toward control values, and there was a protective effect of hypothermia (infarct volume of 211 ± 26 and 40 ± 14 mm³ in normothermic and hypothermic groups, respectively). Thus, hypothermia did not ameliorate the changes in lactate, pH, NAA, or high energy phosphate levels occurring during ischemia, however, during reperfusion there was an improvement in both the recovery of these metabolites and pathological outcome in hypothermic compared with normothermic animals.     

模拟高原和返回平原后大鼠心肌血流量的变化

目的：观察缺氧及停止缺氧后对大鼠心肌血流量的影响。方法：３４只Ｗｉｓｔａｒ大鼠，随机分为４组：①平原对照组；②急性缺氧组；③慢性缺氧组；④返回平原组。以放射性生物微球法测定心肌血流量。结果：急性缺氧引起ＰａＯ２、心输出量及氧运送量降低，但左、右心室心肌血流量明显增加；慢性缺氧时右心室收缩压、血球压积、血液粘滞性及右心室生理指数明显增加，而心肌血流量接近正常。停止缺氧３０ｄ后，上述所有指标均与平原以     

精氨酸加压素（AVP）的衍生物AVP4—8不能作用于AVPV1a受体而诱发电流反应

在微量注射大量肝脏ｍＲＮＡ之后，通过电压箝方法进行功能鉴定，两栖类卵母细胞成功地表达了ＡＶＰＶ１ａ受体。但在灌流ＡＶ４－８溶液时，却不能诱导卵母细胞产生内向振荡电流反应。提示ＡＶＰ４－８不能通过ＡＶＰＶ１ａ受体而介导生理学效应。     

Hemorrhagic fever with renal syndrome virus infection in livers studied by in situ hybridization and immunohistochemistry

ＨｅｍｏｒｒｈａｇｉｃｆｅｖｅｒｗｉｔｈｒｅｎａｌｓｙｎｄｒｏｍｅｖｉｒｕｓｉｎｆｅｃｔｉｏｎｉｎｌｉｖｅｒｓｓｔｕｄｉｅｄｂｙｉｎｓｉｔｕｈｙｂｒｉｄｉｚａｔｉｏｎａｎｄｉｍｍｕｎｏｈｉｓｔｏｃｈｅｍｉｓｔｒｙＹａｎｇＳｈｏｕｊｉｎｇ（杨守京）；Ｌ...     

Localization of Pituitary Adenylate Cyclase-Activating Polypeptide (PACAP) in the Hypothalamus-Pituitary System in Rats: Light and Electron Microscopic Immunocytochemical Studies

The localization of pituitary adenylate cyclase-activating polypeptide (PACAP) in the hypothalamus-pituitary system in rats was examined in light and electron microscopic immunocytochemistry using a specific antiserum to synthetic PACAP 1–38 (R0831). In light microscopic study, intensely PACAP-immunostained perikarya were observed in the supraoptic and paraventricular magnocellular nucleus in the hypothalamus. In the median eminence, many immunoreactive nerve fibers were observed in the internal layer, but a few immunoreactive terminals were noticed in the external layer. In the pituitary gland, numerous immunoreactive nerve fibers were observed in the posterior lobe. In the intermediate lobe, moderately immunostained cells were observed, but in the anterior lobe no immunostained cells were noticed. In electron microscopic study, PACAP-immunoreactivity was examined by avidin-biotin peroxidase complex method. In the perikarya of the supraoptic and paraventricular magnocellular nucleus, DAB-reaction products were distributed diffusely in the cytoplasmic matrix, frequently attaching to the rough-surfaced endoplasmic reticulum. In the nerve terminals of the posterior lobe, reaction products were observed among the secretory granules, but sometimes upon them. In the cells of the intermediate lobe, reaction products were also distributed in the cytoplasmic matrix.     

Effects of chronic amitriptyline administration on saliva from the parotid and submandibular glands of the rat

The effect of prolonged treatment with amitriptyline on the secretory activity of rat salivary glands evoked by parasympathetic nerve stimulation and isoprenaline administration has been studied. Low doses of amitriptyline (10 mg/kg per day for 2 or 4 weeks), did not significantly affect salivary flow evoked by either parasympathetic nerve or isoprenaline stimulation. Higher doses of amitriptyline (50 mg/kg/day for 2 or 4 weeks) however, markedly decreased parasympathetic-evoked salivary secretion (flow and volume) from both parotid and submandibular glands, while isoprenaline-evoked secretions were unaffected. Sodium, potassium, and calcium concentrations of nerve-elicited or isoprenaline-evoked saliva were not significantly altered by amitriptyline treatment. Protein concentration and amylase activity of nerve-elicited parotid saliva were, however, greatly increased by chronic amitriptyline administration. Possible mechanisms for drug-induced increase in nerveelicited salivary protein concentration include changes in cholinergic receptor binding, release of neuropeptides and variations in phosphatidylinositol turnover, which need further study.     

Integration of new regulatory strategies into the network of an endocrine control system: limitation of androgen secretion by rat testis is achieved by substrate-dependent modulation of P450XVII enzyme concentration and catalytic efficiency.

In addition to the well-known control circuits involved in the regulation and adaptation of testicular androgen biosynthesis, it is proposed that two new control strategies are involved in the maintenance of steady-state testosterone secretion rates by testicular Leydig cells. Cytochrome P450XVII (steroid-17 alpha-monooxygenase/steroid-17,20-lyase), one key enzyme in steroid hormone biosynthesis, responds to external human choriogonadotropin stimulation with an oxygen-dependent and substrate flux-dependent inactivation and decomposition, and increased substrate availability decreases the efficiency of androgen formation in favour of abortive intermediate leakage. These results are discussed as a paradigm of substrate-dependent modulation of cytochrome P450 activities.