ABSTRACT
OBJECTIVE@#To investigate the effects of electroacupuncture (EA) on endolymphatic hydrops (EH) and the regulation of arginine vasopressin (AVP)-aquaporin-2 (AQP2) pathway in guinea pigs.@*METHODS@#EH was induced in male guinea pigs by an intraperitoneal injection of AVP. For the treatment, EA was delivered to Baihui (GV 20) and Tinggong (SI 19) acupoints, once per day for 10 consecutive days. In histomorphological studies, cochlear hydrops degree was evaluated by hematoxylin-eosin (HE) staining, and then the ratio of scala media (SM) area to SM + scala vestibuli (SV) area (R value) was calculated. In mechanical studies, a comparison of plasma AVP (p-AVP) concentrations, cyclic adenosine monophosphate (cAMP) levels, vasopressin type 2 receptor (V2R) and AQP2 mRNA expressions in the cochlea were compared among groups.@*RESULTS@#EA significantly reduced cochlear hydrops in guinea pigs (P=0.001). EA significantly attenuated the AVPinduced up-regulation of p-AVP concentrations (P=0.006), cochlear cAMP levels (P=0.003) and AQP2 mRNA expression (P=0.016), and up-regulated the expression of V2R mRNA (P=0.004) in the cochlea.@*CONCLUSIONS@#The dehydrating effect of EA might be associated with its inhibition of AVP-AQP2 pathway activation.
ABSTRACT
The maintenance of the osmolality of body fluids within a very narrow physiologic range is possible by water balance mechanisms that control the intake and excretion of water. Main factors of this process are the thirst and antidiuretic hormon arginine vasopressin (AVP), secretion regulated by osmoreceptors in the hypothalamus. Body water is the primary determinant of the osmolality of the extracellular fluid (ECF), disorders of body water homeostasis can be divided into hypo-osmolar disorders, in which there is an excess of body water relative to body solute, and hyperosmolar disorders, in which there is a deficiency of body water relative to body solute. The sodium is the predominant cation in ECF and the volume of ECF is directly proportional to the content of sodium in the body. Disorders of sodium balance, therefore, may be viewed as disorders of ECF volume. This reviews addresses the regulatory mechanisms underlying water and sodium metabolism, the two major determinants of body fluid homeostasis for a good understanding of the pathophysiology and proper management of disorders with disruption of water and sodium balance.
Subject(s)
Arginine Vasopressin , Body Fluids , Body Water , Extracellular Fluid , Homeostasis , Hypothalamus , Osmolar Concentration , Sodium , ThirstABSTRACT
BACKGROUND: A decreased level of serum arginine vasopressin(AVP) and an increased sensitivity to an exogenous AVP is expected in patients with septic shock who often require a high infusion rate of catecholamines. The goal of the study was to determine whether an exogenous AVP infusion to the patients with septic shock would achieve a significant decrement in infusion rate of catecholamine vasopressors while maintaining hemodynamic stability and adequate urine output. METHODS: Eight patients with septic shock who require a high infusion rate of norepinephrine had received a trial of 4-hour AVP infusion with simultaneous titration of norepinephrine. Hemodynamic parameters and urine output were monitored during the AVP infusion and the monitoring continued up to 4 hours after the AVP infusion had stopped. RESULTS: Mean arterial pressure showed no significant changes during the study period(p=0.197). Norepinephrine infusion rate significantly decreased with concurrent AVP administration(p=0.001). However, beneficial effects had disappeared after the AVP infusion was stopped. In addition, hourly urine output showed no significant changes throughout the trials(p=0.093). CONCLUSION: Concurrent AVP infusion achieved the catecholamine vasopressor sparing effect in the septic shock patients, but there was no evidence of the improvement of renal function. Further study may be indicated to determine whether AVP infusion would provide an organ-protective effect to the septic shock patients.
Subject(s)
Humans , Arginine , Arterial Pressure , Catecholamines , Hemodynamics , Norepinephrine , Shock, SepticABSTRACT
@#ObjectiveTo probe the effect of the electroacupuncture on vascular dementia(VD) and content of arginine vasopressin(AVP) in brain of rats. Methods30 Sprague Dawley rats were made renal hypertension(RHR) by the kidney arteries pinched with silver clip.After 42 days, their bilateral common carotid arteries were blocked repeatedly to cause cerebral ischemia.The Hypertension Vascular Dementia model was made. Then they were divided into model group,electroacupuncture group and medicine group(Dihydroergotoxine,DHET) with 10 in each group. The course was 28 days. The ability of learning and memorizing was observed by water maze, and the content of AVP in brain was detected after treatment. ResultsThe latent period of the electroacupuncture group and medicine group was shorter than that of the model group(P<0.05-0.005), and that of the electroacupuncture group was shorter than medicine group(P<0.05-0.005). In frontal lobe, the contents of AVP in the electroacupuncture and medicine groups were higher than that of model group( P<0.01,P<0.05), and the electroacupuncture group was higher than medicine group in striatum (P<0.05). Conclusions It indicated that electroacupuncture therapy can promote the ability of learning and memorizing and enhance the content of AVP in the brain of VD rats. It's therapeutic effect is better than that of DHET.
ABSTRACT
Aim To observe the effect of the polymerization of HSF1 on the febrile response in fever rabbits,and further to investigate HSF1 action in thermoregulation and the possible central mechanism.Methods 70 rabbits were divided randomly into 4 groups:the control group(N),the quercetin group(Q),the LPS-feverish group(L),the quercetin+LPS-feverish group(Q+L).Changes in body temperature were continually observed;the expression of HSF1 and HSP70 in hypothalamus was detected by Western blot;the content of AVP in hypothalamus and VSA was measured by radioimmunoassay.Results ① The sequence of the maximum change of temperature(△Tmax)from low to high:group Q
ABSTRACT
The author studied the changes of the plasma arginine vasopressin(AVP) levels in 10 brain surgery patient to evaluate the water balance during the postoperative period. The control group was 15 normally hydrated adult subjects. The plasma AVP levels were measured by the radioimmunoassays(RIA). The plasma and urine osmolality was also measured simultaneously using the conventional method. The followings were presented here-in as the results. 1) In control group, the average plasma AVP level was 2.00pg/mL with the range of 0.4 to 5.6pg/mL. There was relative constant relationship between the plasma AVP and the plasma osmolality. The osmotic threshold was 280.4mosm/Kg. 2) In preoperative brain surgery group, the plasma AVP level was similar to control group but the range was wider than control group. There was no constant relationship between the plasma AVP level and the plasma osmolality. 3) The plasma AVP levels were markedly increased in the postoperative brain surgery group. The average level was 10.99pg/mL ranging 0.4 to 47.50pg/mL. In spite of increased plasma AVP concentration, the plasma osmolality and urine/plasma osmolality(Uosm/Posm) ratios were relatively constant to normal control and preoperative brain surgery group. 4) The relationship between the plasma AVP level and the Uosm/Posm ratio was changed according to the plasma AVP level but above 3.0pg/mL it was nearly constant.