ABSTRACT
<p><b>OBJECTIVE</b>To investigate the postburn change in hypothalamic paraventricular beta-endorphin and the roles of delta-receptor in scalded rats.</p><p><b>METHODS</b>Male Sprague-Dawley (SD) rats were randomly divided into 3 groups, i.e. ICI174864, DPDPE and control groups. The rats were inflicted with 20% TBSA of III degree scalding on the back by boiling (100 degrees ) water. The postburn change in the tissue content of the hypothalamic paraventricular beta-endorphin was determined by radioimmuno assay (RIA). The effects of delta-receptor in scalded shock rats were investigated by observing the change of the rats'survival time and cardiac indices after the micro-injection of delta-receptor agonist DPDPE or antagonist ICI174864 into the hypothalamic paraventricle.</p><p><b>RESULTS</b>(1) The tissue content of the hypothalamic paraventricular beta-endorphin increased significantly (P < 0.01) at 1, 2 and 4 postburn hours (PBHs) in the scalded rats. (2) When compared with that of control group, the ratio of the cardiovascular parameters [mean arterial pressure (MAP), dp/dt(max) and HR] were obviously increased at different time points in rats with pre-injection of ICI174864 whereas the ratio was decreased when DPDPE was used. Nevertheless, the change in the heart rate ratio was not obvious whether ICI174864 or DPDPE was used. (3) The average animal survival time in ICI174864 group was much longer than that in DPDPE group.</p><p><b>CONCLUSION</b>An excessive increase in hypothalamic paraventricular beta-endorphin was one of the factors leading to the aggravation of burn shock and earlier death. delta-receptor located in the tissue might have played important roles in the mediation of the action of hypothalamic paraventricular beta-endorphin. It is beneficial to antagonize the action of delta-receptor for the correction of burn shock and for the prolongation of the of life of animals.</p>
Subject(s)
Animals , Male , Rats , Analgesics, Opioid , Pharmacology , Blood Pressure , Burns , Enkephalin, D-Penicillamine (2,5)- , Pharmacology , Enkephalin, Leucine , Pharmacology , Heart Rate , Narcotic Antagonists , Pharmacology , Paraventricular Hypothalamic Nucleus , Metabolism , Rats, Sprague-Dawley , Receptors, Opioid, delta , Physiology , Survival Analysis , beta-Endorphin , MetabolismABSTRACT
Indexes of cardiovascular function and survival time were obser-vedin rats given the following antagonists respectively after scald injury: anti-p-endorphin serum at 10?l, Naloxone at 2mg, ICI174864 at 0.2mg, or TRH at 2 mg, and half of the doses were administered at 1, 2, 3h after scald. The results showed that the cardiac indexes (dP/dtmax, -dP/dtmax and LVSP)were improved, the decrease of mean arterial pressure ( MAP ) and heart rate ( HR ) were delayed after the injections of anti-p-endorphin serum, naloxone or ICIi748e4, and survival time was significantly prolonged in anti ? - endorphin serum group. TRH had little effect on cardiac indexes, MAP and HR were maintained at high level at earlier period, but sharply sloped down in about 210 min after burn. The result suggests that intraventri-cular administration of anti-?-endorphin, naloxone or ICI174864 had much benefit on scald shock, but TRH was uncertain at least in the treatment of scald shock.
ABSTRACT
The effects of electro-and chemo-stimulating (ES, CS) supraoptic nucleus (SON) on analgesia and electroacupuncture (EA) analgesia were observed using potassium inotophoresis induced tail-flick in rats. The results showed that: different electrical current (12.5 ~ 50 ?A) stimulating SON elevated the PT (P
ABSTRACT
Effect of scalding on secretory function of beta-endorphin neuron in the arcuate nucleus of the rat hypothalamus was studied semiquantitatively using immunocytochemistry and image analysis. The results showed that the number of beta-endorphin neurons and area of positive products reduced significantly (P
ABSTRACT
The immune function of rats was markedly suppressed following burn injury. At 24 h after burn, the lymphoproliferative response to Con A and IL-1 and IL-2 production in burned rats were significantly reduced, as compared with control animals. At 72 h after burn the immune parameters as above were at the lowerest levels. At 120 h after burn, a slight elevation of immune function was observed, but still lower than the levels of controls. The results of radioimmunoassay of ?-endorphin and dynorphin A in plasma showed that the concentration of ?-endorphin in plasma was not markedly changed after burn except at 2 h after injury, and that of dynorphin A in plasma was reduced markedly after burn injury. The dynamic change of circulating dynorphin A in plasma was coincident with that of immune function. Our results suggest that burn-induced immunosuppression may be related to decrease of circulating dynorphin A levels.
ABSTRACT
Methods including stimulation, cauterization, of nuclei and measurement of pain threshold were used to clarify the role of paraventricular nucleus of hypothalamus (PVH) in pain regulation. Results showed that electrical or L-glutamate sodium stimulation of PVH could elevate the pain threshold in the rat dose-dependently, electrical cauterization of PVH could reduce the pain threshold; and removal of the pituitary gland could not influence the effect of L-glutamate sodium on pain threshold. These results suggest that PVH may play an important role in pain regulation.
ABSTRACT
In this study, radioimmunoassay (RIA) was performed to measure the change of immunoreactive-oxytocin (ir-OT) content in rat brain' nuclei related pain modulation, spinal cord, pituitary, adrenal gland and plasma by electroacupuncture "Zusanli" (EA) for 30rnin or pain stimulation for 2min. In the EA group, OT content was decreased greatly in the hypothalamic supraoptic N., while increased significantly in the hypothalamic ventromedial N., raphe magnus N., globus pallidus, spinal cord and adrenal gland, and there were no significant change in the hypothalamic paraventricular N., raphe dorsal N., locus ceruleus, pituitary arid plasma. There were also significant changes of OT content in rat brain, spinal cord and pituitary in the pain stimulation group, which are different from those of the EA group. The above results suggest that the changes of OT content in the EA group are specific, and provide evidence for involvement of endogenous OT in the central nervous system in acupuncture analgesia
ABSTRACT
The contents of ir-oxytocin (it-OT), ir-Arg-yasopressin (ir-AVP) and ir-?-endorphin (ir-?-EP) in hypothalamus, pituitary and plasma were measured by. radioimmunoassay (RIA) when the rats were swimming. It was showed that the ir-OT contents in hypothalamus, pituitary and plasma were significantly increased in the animals having swum 1, 5, 15 and 20min (P
ABSTRACT
The effects of arginine vasopressin (AVP) on the contents of ir-?-EP and ir-Dyn A1-13 in ischemic brain regions of Mongolian gerbils were observed with radioimmunoassay in this study.The results showed that the contents of ir-?-EP were significantly increased and those of ir-Dyn A1-13 were decreased in ischemic cortex and hypothalamus after injection of AVP into the lateral ventricle. However, the contents of ir-?- EP were markedly decreased and those of ir-Dyn A1-13 were unchanged significantly in the ischemic cortex and hypothalamus after intraventricular infusion of AVP antiserum.
ABSTRACT
The changes of immunoreactive neurotensin (ir-NT) contents in the brain areas, pituitary gland and plasma in the trautized rats were observed by radioimmunoassay. The results showed the significant changes of the ir-NT contents in the hypothalamus, pituitary gland, plasma, injured tissue, hippocampus, central gray and spinal cord in the posttraumatic rats at different intervals. A predominant characterization of the change of ir-NT levels in the brain areas, pituitary gland and plasma, was the dramatical decrease at various times except for the hypothalamus, central gray, and hippocampus with biphasic alterations. The ir-NT contents in the frontal cortex, pons and medulla also displayed changes to different extent under the acute craniocerebral trauma condition These results suggest that NT may play a role in the pathophysiology of traumatic injury.
ABSTRACT
The purpose of this experiment was to study the role of arginine vasopressin (AW) in acute cerebral ischemic edema in mongolian gerbils. The results showed that intracerebroventricular injection (ICV) of AVP exacerbated the ischemic brain edema, while ICV of AW antiserum significantly decreased the ischemic brain edema. Nimodipine couldn't block this role of AW in ischemic brain edema. The cortical Na+ -K+ ATPase activity was significantly decreased, the contents of cAMP in the ischemic cortex and hypothalamus and the contents of cGMP in the hypothalamus were remarkably increased after ICV of AW. These suggest AW was involved in the pathophysiologic process of acute ischemic brain edema. And its mechanism might be the effect of AW on AW receptor mediated by cAMP, cGMP, and that in turn inhibited the Na+ -K+ ATPase activity of brain cell membrane, then exaggerated the formation of ischemic brain edema.
ABSTRACT
The dynamic changes of immunoreactive dynorphin1-13 (ir-Dyn1-13) contents in 18 burned patients were studied by radioimmunoassay. It was found that ir-Dyn began to increase gradually at the onset of burn and remained at a relatively high levels by the time of preliminary wound healing. Plasma ir-Dyn increased gradually after bum and decreased abruptly before death in one severely burned patient who died of respiratory failure at the third week. The results suggest that Dyn may have a protective effect on the burned patients.