Physiological changes during thermoregulation and fever in urethan-anesthetized rats

1988 ◽  
Vol 255 (1) ◽  
pp. R73-R81 ◽  
Author(s):  
T. J. Malkinson ◽  
K. E. Cooper ◽  
W. L. Veale
Keyword(s):  
Interleukin 1 ◽  
Cerebral Ventricle ◽  
Arterial Blood ◽  
Dependent Change ◽  
Male Wistar Rats ◽  
Series Of Experiments ◽  
Dose Dependent ◽  
Conscious Animals ◽  
Maintain Body Temperature ◽  
Lateral Cerebral Ventricle

Adult male Wistar rats were anesthetized with urethan (1.5 g/kg). They were unable to maintain body temperature (Tb) in a warm (32 degrees C) or cool (9 degrees C) environment or at a laboratory room temperature of 22 degrees C. Tb was allowed to fall to 35.8, 34.5, or 33.3 degrees C, and prostaglandin E1 (PGE1, 400 ng) was delivered into a lateral cerebral ventricle. An immediate feverlike rise in Tb resulted, accompanied by vigorous shivering. Animals were vasoconstricted throughout. When Tb was raised to and maintained at 38.3 or 39.5 degrees C, animals also responded with a fever; however, the magnitude of the fever diminished as the starting Tb increased. In a series of experiments in which Tb was maintained (36.8-37.4 degrees C) by means of a heating pad, PGE1 delivered into a lateral cerebral ventricle or into the anterior hypothalamus caused a dose-dependent change in Tb, which was similar in time of onset, magnitude, and duration to that observed in conscious animals. This fever was accompanied by shivering and increased O2 uptake, heart rate, arterial blood pressure, respiratory rate, and intracranial pressure during the rising phase of the fever, and vasodilation of the paws occurred during defeveresence. Animals were also able to develop a dose-dependent rise in Tb in response to purified human interleukin 1.

Central effect of endothelin on blood pressure in conscious rats

1989 ◽  
Vol 256 (6) ◽  
pp. H1747-H1751 ◽  
Author(s):  
Y. Ouchi ◽  
S. Kim ◽  
A. C. Souza ◽  
S. Iijima ◽  
A. Hattori ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Conscious Rats ◽  
Arterial Blood ◽  
Norepinephrine Concentration ◽  
Artificial Cerebrospinal Fluid ◽  
Male Wistar Rats ◽  
The Mean ◽  
Dose Dependent Increase ◽  
Dose Dependent ◽  
Lateral Cerebral Ventricle

This study was conducted to investigate the effect of intracerebroventricular administration of endothelin (EDT), a novel potent vasoconstricting peptide, on blood pressure in conscious rats. The lateral cerebral ventricle of male Wistar rats was cannulated, and the femoral artery was also cannulated to measure the mean arterial blood pressure (MABP) and heart rate (HR). EDT dissolved in 10 microliters of artificial cerebrospinal fluid (ACSF) (8.25-66 pmol icv) provoked a dose-dependent increase in MABP. EDT also increased HR, although the effect of 66 pmol was variable. Intracerebroventricular ACSF did not provoke any effects on MABP and HR. Intracerebroventricular EDT also provoked contralateral rotational behavior. Pretreatment with 2 mg/kg iv phenoxybenzamine significantly suppressed the 16.5 pmol icv EDT-induced increase in MABP. Moreover, 16.5 pmol icv EDT markedly increased plasma epinephrine and norepinephrine concentration. These results indicate that EDT has a central pressor action, and the action might be mediated, at least in part, by catecholamine release to the periphery. EDT might play a role in the central control of blood pressure, although the physiological implications have not yet been determined.

Cholecystokinin is not a peripheral satiety signal in the dog

1985 ◽  
Vol 249 (6) ◽  
pp. G733-G738
Author(s):  
T. N. Pappas ◽  
R. L. Melendez ◽  
K. M. Strah ◽  
H. T. Debas
Keyword(s):  
Pancreatic Enzyme ◽  
Cerebral Ventricle ◽  
Gastric Distension ◽  
Dependent Manner ◽  
Gallbladder Contraction ◽  
Sham Feeding ◽  
Pancreatic Enzyme Secretion ◽  
Pancreatic Fistulas ◽  
Dose Dependent ◽  
Lateral Cerebral Ventricle

The doses of cholecystokinin (CCK) that have been shown to cause satiety after peripheral administration are pharmacological and whether "physiological" doses of exogenous CCK or endogenously released CCK have a satiety effect is not known. The purpose of the present study is threefold: to compare the potency of endogenous and exogenous CCK for their satiety, cholecystokinetic, and pancreozyminic actions; to determine whether small doses of CCK in the presence of gastric distension cause satiety; and to test the satiety effect of CCK administered centrally into the lateral cerebral ventricle. Dogs were prepared with cerebroventricular guides and esophageal and duodenal fistulas (n = 4), with chronic bile fistulas (n = 8), and chronic pancreatic fistulas (n = 7). Satiety effect was quantified in the esophageal fistula dog by the amount of blenderized food sham fed within 7.5 min. Duodenal perfusion of fat, used as a releaser of endogenous CCK, stimulated pancreatic protein, and gallbladder contraction with D50 values of 1.5 and 0.3 mmol/h, respectively, but had no effect on the volume sham fed (316 +/- 82 ml/min without and 371 +/- 41 ml/min with the maximal dose of sodium oleate infused). The D50 values of CCK-8 (pmol X kg-1 X h-1) for satiety and for stimulation of pancreatic enzyme secretion and gallbladder contraction were 440, 120, and 22, respectively. Injection of CCK-8 into the lateral cerebral ventricle inhibited sham feeding in a dose-dependent manner. We conclude that duodenal fat in doses producing maximal gallbladder and pancreatic stimulation has no satiety effect in the dog.(ABSTRACT TRUNCATED AT 250 WORDS)

Enhanced fever following castration: possible involvement of brain arginine vasopressin

1988 ◽  
Vol 254 (3) ◽  
pp. R513-R517 ◽  
Author(s):  
Q. J. Pittman ◽  
T. J. Malkinson ◽  
N. W. Kasting ◽  
W. L. Veale
Keyword(s):  
Arginine Vasopressin ◽  
Wistar Rats ◽  
Prostaglandin E1 ◽  
Interleukin 1 ◽  
Lateral Septum ◽  
Male Wistar Rats ◽  
Thermal Indexes ◽  
The Brain ◽  
Lateral Cerebral Ventricle

Arginine vasopressin (AVP) is thought to act as an antipyretic in the ventral-septal area (VSA) of the brain. As AVP content of this area has been shown to be virtually eliminated following long-term castration, we have tested the hypothesis that castrated rats would display enhanced fevers. Four months after castration (or sham castration), male Wistar rats were given prostaglandin E1 (200 ng), purified interleukin 1 (25 U), or saline (5 microliters) into a lateral cerebral ventricle. Castrated rats displayed fevers of longer duration, reflected as significantly enhanced thermal indexes, than did age-matched sham-operated controls. Castrated rats also were less able to defend their body temperatures to ambient heat stress but not to ambient cold. AVP content of VSA and lateral septum, but not of hippocampus, of castrated rats was significantly reduced; oxytocin content of the three areas was unchanged following castration. These data support earlier studies concerning effects of castration on septal AVP content and are consistent with the possibility that AVP is an antipyretic in the VSA of the rat.

Vasorelaxant and Antihypertensive Effects of Mentha pulegium L. in Rats: An in vitro and in vivo Approach

2020 ◽  
Vol 20 ◽  
Author(s):  
Mohammed Ajebli ◽  
Mohamed Eddouks
Keyword(s):  
Blood Pressure ◽  
Acute Experiment ◽  
Antihypertensive Activity ◽  
Mentha Pulegium ◽  
In Vitro Experiment ◽  
Arterial Blood ◽  
Dose Dependent ◽  
Ca2 Channels

Aims and objective: The aim of the study was to investigate the effect of aqueous aerial part extract of Mentha pulegium L. (Pennyrile) (MPAE) on arterial pressure parameters in rats. Background: Mentha pulegium is a medicinal plant used to treat hypertension in Morocco. Material and methods: In the current study, MPAE was prepared and its antihypertensive activity was pharmacologically investigated. L-NAME-hypertensive and normotensive rats have received orally MPAE (180 and 300 mg/kg) during six hours for the acute experiment and during seven days for the sub-chronic treatment. Thereafter, systolic, diastolic, mean arterial blood pressure and heart rate were evaluated. While, in the in vitro experiment, isolated denuded and intact thoracic aortic rings were suspended in a tissue bath system and the tension changes were recorded. Results: A fall in blood pressure was observed in L-NAME-induced hypertensive treated with MPAE. The extract also produced a dose-dependent relaxation of aorta pre-contracted with NE and KCl. The study showed that the vasorelaxant ability of MPAE seems to be exerted through the blockage of extracellular Ca2+ entry. Conclusion: The results demonstrate that the extract of pennyrile exhibits antihypertensive activity. In addition, the effect may be, at least in part, due to dilation of blood vessels via blockage of Ca2+ channels.

scholarly journals Differentiation factor/leukemia inhibitory factor protection against lethal endotoxemia in mice: synergistic effect with interleukin 1 and tumor necrosis factor.

1992 ◽  
Vol 175 (4) ◽  
pp. 1139-1142 ◽  
Author(s):  
H R Alexander ◽  
G G Wong ◽  
G M Doherty ◽  
D J Venzon ◽  
D L Fraker ◽  
...  
Keyword(s):  
Tumor Necrosis Factor ◽  
Leukemia Inhibitory Factor ◽  
Tumor Necrosis ◽  
Interleukin 1 ◽  
Inhibitory Factor ◽  
Dependent Manner ◽  
Lps Challenge ◽  
Differentiation Factor ◽  
Dose Dependent ◽  
Necrosis Factor

Differentiation factor (D factor), also called leukemia inhibitory factor (LIF), is a glycoprotein that has been increasingly recognized to possess a wide range of physiological activities. We examined the possibility that the administration of D factor may confer beneficial effects and enhance host resistance against lethal endotoxemia. A single intravenous dose of recombinant human D factor completely protected C57/Bl6 mice from the lethal effect of Escherichia coli endotoxin (lipopolysaccharide [LPS]). The protective effects were dose dependent and observed when administered 2-24 h before LPS. Previous work has shown that interleukin 1 (IL-1) and tumor necrosis factor (TNF) also protect against a subsequent LPS challenge in a dose-dependent manner. When human D factor was combined with sub-protective doses of IL-1 beta or TNF-alpha, there was dramatic synergistic protection against a subsequent lethal LPS challenge.

scholarly journals Regulation of rabbit acute phase protein biosynthesis by monokines

1988 ◽  
Vol 253 (3) ◽  
pp. 851-857 ◽  
Author(s):  
A Mackiewicz ◽  
M K Ganapathi ◽  
D Schultz ◽  
D Samols ◽  
J Reese ◽  
...  
Keyword(s):  
Acute Phase ◽  
Serum Amyloid A ◽  
Interleukin 1 ◽  
Serum Amyloid ◽  
C Reactive Protein ◽  
Reactive Protein ◽  
Amyloid A ◽  
Primary Hepatocyte Cultures ◽  
Dose Dependent ◽  
Necrosis Factor

We defined the acute phase behaviour of a number of rabbit plasma proteins in studies (in vivo) and studied the effects of monokine preparations on their synthesis by rabbit primary hepatocyte cultures. Following turpentine injection, increased serum levels of C-reactive protein, serum amyloid A protein, haptoglobin, ceruloplasmin, and decreased concentrations of albumin were observed. In contrast to what is observed in man, concentrations of alpha 2-macroglobulin and transferrin were increased. Co-culture of primary hepatocyte cultures with lipopolysaccharide-activated human peripheral blood monocytes or incubation with conditioned medium prepared from lipopolysaccharide-activated human or rabbit monocytes resulted in dose-dependent induction of serum amyloid A, haptoglobin, ceruloplasmin and transferrin and depression of albumin synthesis, while C-reactive protein synthesis and mRNA levels remained unchanged. A variety of interleukin-1 preparations induced dose-dependent increases in the synthesis and secretion of serum amyloid A, haptoglobin, ceruloplasmin and transferrin and decreased albumin synthesis. Human recombinant tumour necrosis factor (cachectin) induced a dose-dependent increase in synthesis of haptoglobin and ceruloplasmin. In general, human interleukin-1 was more potent than mouse interleukin-1 and tumour necrosis factor. None of the monokines we studied had an effect on C-reactive protein synthesis or mRNA levels. These data confirm that C-reactive protein, serum amyloid A, haptoglobin and ceruloplasmin display acute phase behaviour in the rabbit, and demonstrate that, in contrast to their behaviour in man, alpha 2M and transferrin are positive acute phase proteins in this species. While both interleukin-1 and tumour necrosis factor regulate biosynthesis of a number of these acute phase proteins in rabbit primary hepatocyte cultures, neither of these monokines induced C-reactive protein synthesis. Comparison of these findings with those in human hepatoma cell lines, in which interleukin-1 does not induce serum amyloid A synthesis, suggests that the effect of interleukin-1 on serum amyloid A synthesis may be indirect.

cAMP inhibition of interleukin-1-induced interleukin-6 production by human lung fibroblasts

1993 ◽  
Vol 264 (3) ◽  
pp. L253-L260 ◽  
Author(s):  
R. J. Zitnik ◽  
T. Zheng ◽  
J. A. Elias
Keyword(s):  
Human Lung ◽  
Interleukin 1 ◽  
Cell Number ◽  
Lung Fibroblasts ◽  
Intracellular Camp ◽  
Inhibitory Effects ◽  
Mrna Accumulation ◽  
Human Lung Fibroblasts ◽  
Dose Dependent ◽  
Necrosis Factor

We characterized the effects of agents that alter intracellular adenosine 3',5'-cyclic monophosphate (cAMP) on the interleukin (IL)-6 production of human lung fibroblasts. Unstimulated fibroblasts did not produce significant amounts of IL-6. Recombinant (r) tumor necrosis factor (TNF) weakly stimulated, recombinant interleukin-1-alpha (rIL-1 alpha) strongly stimulated, and rIL-1 alpha and rTNF in combination synergistically augmented fibroblast IL-6 production. Prostaglandin (PG)E1, forskolin, dibutyryl cAMP (DBcAMP), 3-isobutyl-1-methylxanthine (IBMX), and cholera toxin did not cause a detectable alteration in the IL-6 production of unstimulated fibroblasts. However, these agents inhibited the IL-6 production of rIL-1 and rIL-1 plus rTNF-stimulated cells. These effects were dose dependent with a concentration of 2 x 10(-9) M PGE1, 5 x 10(-6) M forskolin, 5 x 10(-4) M DBcAMP, and 1 x 10(-3) M IBMX decreasing rIL-1 alpha (2.5 ng/ml)-induced IL-6 production by approximately 50%. The inhibitory effects of these agents, correlated with their ability to induce fibroblast cAMP accumulation, could not be explained by alterations in cell number or viability and were appreciable even when cAMP modifiers were added to fibroblast culture, 1 h after rIL-1. They were also at least partly specific for rIL-1, since these agents increased the IL-6 production of rTNF-stimulated cells. These cAMP-induced alterations in IL-6 production were associated with corresponding alterations in IL-6 mRNA accumulation. Nuclear run-on analysis demonstrated that the inhibitory effects of PGE1 were associated with a comparable decrease in IL-6 transcription. Agents that increase the levels of intracellular cAMP inhibit rIL-1-induced IL-6 by human lung fibroblasts.

POTENTIAL DIURETIC EFFECT OF CURCUMA AMADA ROXB. RHIZOME EXTRACTS

INDIAN DRUGS ◽  
2013 ◽  
Vol 50 (04) ◽  
pp. 34-38
Author(s):  
P Bommannavar ◽  
◽  
K. Patil
Keyword(s):  
Aqueous Extract ◽  
Urine Volume ◽  
Control Group ◽  
Aqueous Extracts ◽  
Diuretic Activity ◽  
Curcuma Amada ◽  
Male Wistar Rats ◽  
Total Urine ◽  
Dose Dependent Increase ◽  
Dose Dependent

The present study was undertaken to establish the diuretic activity of alcoholic and aqueous extract of dried rhizomes of Curcuma amada Roxb in rats. Alcoholic and aqueous extracts of rhizomes were administered to experimental male Wistar rats orally at doses of 250 and 500 mg/kg and compared with furosemide (10 mg/kg) as the reference standard. The parameters measured for diuretic activity were total urine volume, urine electrolyte concentration such as sodium, potassium and chloride have been evaluated. The rats treated with alcoholic and aqueous extract of Curcuma amada in a dose of 250 and 500 mg/kg showed higher urine output when compared to the respective control. Both alcoholic and aqueous extracts have showed a significant dose-dependent increase in the excretion of electrolytes when compared to the control group. The result indicates that alcoholic and aqueous extract is an effective natriuretic and kaliuretic diuretic, which supports the traditional claim about the Curcuma amada Roxb being used as diuretics.

Measurements of metabolic rate in rats: a comparison of techniques

1988 ◽  
Vol 65 (2) ◽  
pp. 964-970 ◽  
Author(s):  
T. I. Musch ◽  
A. Bruno ◽  
G. E. Bradford ◽  
A. Vayonis ◽  
R. L. Moore
Keyword(s):  
Metabolic Rate ◽  
Maximal Exercise ◽  
Ambient Air ◽  
Open Circuit ◽  
Submaximal Exercise ◽  
Co2 Production ◽  
Arterial Blood ◽  
In Series ◽  
Series Of Experiments ◽  
Four Levels

Two different open-circuit techniques of measuring metabolic rate were examined in rats at rest and during exercise. With one technique ambient air was drawn through a tightly fitting mask that was secured to the rat's head, whereas with the other technique the rat was placed into and ambient air was drawn through a Plexiglas box. Two series of experiments were performed. In series I, two groups were studied that consisted of rats that had received myocardial infarctions produced by coronary arterial ligations and rats that had received sham operations. In this series of experiments O2 uptake (VO2) and CO2 production (VCO2) were measured at rest, during four levels of submaximal exercise, and during maximal treadmill exercise in the same group of rats by use of both techniques in random order. VO2, VCO2, and the calculated respiratory exchange ratio (R) were similar at rest, during the highest level of submaximal exercise (20% grade, 37 m/min), and during maximal exercise; however, VO2 and VCO2 were significantly lower with the metabolic box technique compared with the mask technique during the three lowest work loads (5% grade, 19 m/min; 10% grade, 24 m/min; and 15% grade, 31 m/min). These differences appeared to be associated with a change in gait produced when the mask was worn. In series II, the arterial blood gas and acid-base responses to both submaximal and maximal exercise were measured using both techniques in a group of instrumented rats that had a catheter placed into the right carotid artery.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Acute pulmonary effects of aerosolized nicotine

2019 ◽  
Vol 316 (1) ◽  
pp. L94-L104 ◽  
Author(s):  
Shama Ahmad ◽  
Iram Zafar ◽  
Nithya Mariappan ◽  
Maroof Husain ◽  
Chih-Chang Wei ◽  
...  
Keyword(s):  
Electronic Cigarettes ◽  
White Blood Cells ◽  
Weight Ratio ◽  
Airway Epithelial Cells ◽  
Mrna Levels ◽  
Safe Alternative ◽  
Arterial Blood ◽  
Dose Dependent Increase ◽  
Dose Dependent ◽  
E Cadherin

Nicotine is a highly addictive principal component of both tobacco and electronic cigarette that is readily absorbed in blood. Nicotine-containing electronic cigarettes are promoted as a safe alternative to cigarette smoking. However, the isolated effects of inhaled nicotine are largely unknown. Here we report a novel rat model of aerosolized nicotine with a particle size (~1 μm) in the respirable diameter range. Acute nicotine inhalation caused increased pulmonary edema and lung injury as measured by enhanced bronchoalveolar lavage fluid protein, IgM, lung wet-to-dry weight ratio, and high-mobility group box 1 (HMGB1) protein and decreased lung E-cadherin protein. Immunohistochemical analysis revealed congested blood vessels and increased neutrophil infiltration. Lung myeloperoxidase mRNA and protein increased in the nicotine-exposed rats. Complete blood counts also showed an increase in neutrophils, white blood cells, eosinophils, and basophils. Arterial blood gas measurements showed an increase in lactate. Lungs of nicotine-inhaling animals revealed increased mRNA levels of IL-1A and CXCL1. There was also an increase in IL-1α protein. In in vitro air-liquid interface cultures of airway epithelial cells, there was a dose dependent increase in HMGB1 release with nicotine treatment. Air-liquid cultures exposed to nicotine also resulted in a dose-dependent loss of barrier as measured by transepithelial electrical resistance and a decrease in E-cadherin expression. Nicotine also caused a dose-dependent increase in epithelial cell death and an increase in caspase-3/7 activities. These results show that the nicotine content of electronic cigarettes may have adverse pulmonary and systemic effects.

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