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1.
Acute Immobilization Stress and Intraventricular Injection of CRF Suppress Naloxone-Induced LH Release in Ovariectomized Estrogen-Primed Rats 总被引:1,自引:0,他引:1
Tatsuo Akema Atsuhiko Chiba Reiji Shinozaki Morihiro Oshida Fukuko Kimura & Jun-ichi Toyoda 《Journal of neuroendocrinology》1996,8(8):647-652
The present study was undertaken to evaluate the role and possible interaction of the endogenous opioid peptide (EOP) and corticotropin-releasing factor (CRF) in the acute stress-induced suppression of gonadotropin secretion in ovariectomized estrogen-primed rats. An intravenous (i.v.) injection of naloxone (10 or 20 mg/kg), an EOP antagonist, significantly elevated serum luteinizing hormone (LH) levels within 10 min in non-stressed animals. The naloxone-induced LH release was completely eliminated when tested 30 min after the onset of acute immobilization. In a subsequent study, it was found that suppression of the naloxone-induced LH release occurred as early as 5 min after the stress onset, and was still evident 60 min after the end of a 30-min period of immobilization. The effect of naloxone was restored 3 h after liberation of the animal from the 30-min immobilization. An intraventricular (i.c.v.) injection of CRF (1 or 5 μg) also significantly suppressed, in a dose-related manner, the effect of a subsequent i.v. injection of naloxone. However, an i.c.v. injection of α -helical CRF(9-41) (25 or 50 μg), a CRF antagonist, prior to immobilization, could not interfere with the suppressive effect of stress on naloxone-induced LH release. These results suggest that both acute immobilization stress and CRF can inhibit the LH secretory activity without mediation by EOP neurons. However, the stress-related suppression may involve non-CRF mechanism(s). 相似文献
2.
Effects of a newly introduced polyoxyethylene-modified superoxide dismutase (SOD-POE) on reperfusion induced arrhythmias were examined in the pentobarbital anesthetized rat. Reperfusion induced arrhythmias were elicited by occlusion of the left anterior descending coronary artery (LAD) for 15 min and subsequent release. The LAD occlusion was performed by compressing the artery using a suction cup of 2 mm in diameter placed on the LAD to which negative pressure was applied. The LAD occlusion and release was repeated at an interval of 30 min. SOD-POE or human SOD (h-SOD) (1000 U/kg) was injected intravenously 15 min prior to the occlusion at the second trial of the occlusion. In the control group, various types of arrhythmias including ventricular fibrillation (Vf), ventricular tachycardia (VT), premature ventricular contraction (PVC) and premature atrial contraction (PAC) were elicited immediately after release of the occlusion. In the SOD-POE-treated group, Vf and VT were completely prevented and the numbers of PVC and PAC significantly decreased, while pretreatment with h-SOD did not prevent the occurrence of reperfusion induced arrhythmias. The protective effects of SOD-POE lasted for more than 90-120 min. The plasma half life for SOD-POE was 10.8 hr, while that for h-SOD was 8.6 min. Results indicate that intravenous administration of SOD-POE would provide a new means of preventing reperfusion induced arrhythmias occurring in clinical situations. 相似文献
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4.
T Takatorige K Tatara K Kuroda N Nakanishi C Nishigaki E Okamoto N Nishi Y Nakagawa C Rin F Shinsho 《[Nihon kōshū eisei zasshi] Japanese journal of public health》1990,37(4):255-262
This study was done to identify factors affecting present hospitalization versus home care in 4,578 elderly subjects representing 87.1% of the elderly population living in S. city near Osaka. Subjects or their families were asked by interviews regarding the age of the subjects, the kind of persons living together in the family unit, the kind of housing, the number of rooms in the family dwelling, and health conditions. Subjects were also asked whether he or she could walk unassisted and whether home care would be preferred in case of an illness. Among the 153 hospitalized subjects, ability to walk, age, and the number of rooms were all significant factors, in decreasing order. Among the 1,193 persons who preferred home care in case of an illness, the number of rooms, age, ability to walk, and the size of the family unit were all significant factors, in decreasing order. Among subjects who could not walk unassisted, the number of rooms was the main factor determining their admission and not preferring home care if their condition worsened. Thus, although the ability to walk is the major factor among the factors we investigated, housing conditions are also important if home care is to be possible. 相似文献
5.
Electron-microscopic and immunohistochemical study of beta-2-microglobulin-related amyloidosis. 总被引:1,自引:0,他引:1
beta 2-Microglobulin (beta 2-MG)-related amyloidosis has been reported as a complication in long-term hemodialysis patients. We observed beta 2-MG amyloid deposits in synovial sheaths, bone cysts and gastric mucosa. They showed unique ultrastructural features, that is bundles or nodules consisting of curved or linear amyloid fibrils, associated with various cell reactions. The electron-microscopic histochemical study showed that they strongly stained with periodic acid-silver methenamine stain. A similar phenomenon was noticed in the spicules or bundles of amyloid fibrils in primary and secondary renal amyloidosis. With the cationic reagent toluidine blue 0, proteoglycan-like structures were observed around amyloid bundles and nodules, but not on each fibrils. Based on these results, we postulate that there is a close relationship between ultrastructural features and histochemical characteristics in beta 2-MG amyloid fibrils. 相似文献
6.
The utilization of radical operation in gastric cancer cases has led to the development of various operation techniques. With the improvement in perioperative management it can be said that age no longer is a restriction. A study of gastric cancer prognosis indicates an upward trend in survival since 1960 along with the increased detection of early cancer. This suggests the most importance of early detection in increasing the therapeutic results obtained in cases of gastric cancer. In cases with advanced cancer, 5-year survival rate of 44.7 per cent was attained through such aggressive actions as extended dissection of lymph nodes and combined resection of surrounding organs with evaluation of the macroscopic classification of the cancer. 相似文献
7.
Endotoxin-induced uveitis (EIU) in the rat: A study of inflammatory and immunological mechanisms 总被引:2,自引:0,他引:2
Endotoxin-induced uveitis (EIU) can be produced by systemic injection of endotoxin (ET). It is not clear yet why exclusive ocular involvement occurs in this model. To clarify this question and to establish the sequence of inflammatory events, EIU was induced in Lewis rats by footpad injection of Salmonella ET. Ocular inflammatory response (anterior chamber cells and proteins), aqueous inflammation mediators (thromboxane B2, prostaglandin E2, leukotriene B4 and substance P) and MHC class 2 (Ia) antigen expression in the ciliary body were monitored for 72 hours. Thromboxane B2 was detected early in the aqueous humor, peaking already 1 hour after ET injection. Prostaglandin E2 & leukotriene B4 peaks and a second peak of thromboxane B2 were recorded 18 hours after ET-injection, at the time of maximal ocular inflammation. MHC-class 2 expression was first detected in the ciliary body stroma at the vascular level 6 hours after ET injection and was massively expressed in the ciliary body epithelium at 18 and 72 hours. It is hypothetized that ciliary body endothelium is particularly sensitive to the effect of ET and is the site of thrombocyte adherence. Vascular damage leads in succession to cellular infiltration, release of inflammation mediators and disruption of blood-ocular barrier. MHC-class 2 expression is a secondary phenomenon and is probably at the origin of additional tissue damage from immune effector mechanisms. 相似文献
8.
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 NG -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. 相似文献
9.
10.
O Nishi 《Journal of cataract and refractive surgery》1987,13(3):317-320
The procedure used for an anterior capsulotomy is extremely important for successful in-the-bag intraocular lens insertion. An incision line in the extreme periphery may obscure the margin of the residual anterior capsule and make it difficult to confirm the position of the implanted lens. I describe a U-shaped anterior capsulotomy that facilitates in-the-bag insertion, discuss the importance of the location of the positioning holes for proper rotation, and introduce a modified J-loop posterior lens with the positioning holes in an alternative position. 相似文献