Arginine vasopressin does not mediate the attenuated febrile response to intravenous IL-1β in pregnant rats

1999 ◽  
Vol 276 (2) ◽  
pp. R450-R454 ◽  
Author(s):  
Heather L. Eliason ◽  
James E. Fewell
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Receptor Antagonist ◽  
Core Temperature ◽  
Arginine Vasopressin ◽  
Temperature Response ◽  
Endogenous Pyrogen ◽  
Febrile Response ◽  
Pregnant Rats ◽  
The Central Nervous System

Rats have an attenuated febrile response to intravenous endogenous pyrogen [e.g., interleukin-1β (IL-1β)] near the term of pregnancy. The present experiments were carried out on 25 nonpregnant and 32 pregnant rats to test the hypothesis that arginine vasopressin functioning as an endogenous antipyretic substance in the central nervous system mediates this attenuated febrile response. An intravenous injection of recombinant rat IL-1β (rrIL-1β) after intracerebroventricular vehicle produced a significant increase in core temperature in both nonpregnant and pregnant animals, the magnitude and duration of which was greater in the nonpregnant rats. In nonpregnant rats, intravenous rrIL-1β after intracerebroventricular vasopressin V1-receptor antagonist accentuated the core temperature response compared with that observed with intravenous rrIL-1β after intracerebroventricular vehicle. In pregnant animals, however, intravenous rrIL-1β after intracerebroventricular vasopressin V1-receptor antagonist produced a decrease in core temperature rather than an increase in core temperature, which was observed with intravenous rrIL-1β after intracerebroventricular vehicle. Thus our data do not support the hypothesis that a pregnancy-related activation of arginine vasopressin as an endogenous antipyretic substance in the central nervous system attenuates the febrile response to intravenous rrIL-1β near the term of pregnancy in rats.

scholarly journals AVP mediates the attenuated febrile response to administration of PGE1 in rats near term of pregnancy

1998 ◽  
Vol 275 (3) ◽  
pp. R691-R696 ◽  
Author(s):  
Heather L. Eliason ◽  
James E. Fewell
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Receptor Antagonist ◽  
Core Temperature ◽  
Arginine Vasopressin ◽  
Intracerebroventricular Injection ◽  
Intracerebroventricular Administration ◽  
Febrile Response ◽  
The Central Nervous System ◽  
Near Term

Rats have an attenuated febrile response to intracerebroventricular injection of PGE1 near the term of pregnancy, the mechanism of which is unknown. The present experiments were carried out to test the hypothesis that arginine vasopressin (AVP), functioning as an endogenous antipyretic substance in the central nervous system, mediates this attenuated febrile response. The febrile response to intracerebroventricular injection of 0.2 μg PGE1 was determined in pregnant and nonpregnant rats after an intracerebroventricular injection of either vehicle or a vasopressin V1-receptor antagonist. After intracerebroventricular administration of vehicle, intracerebroventricular administration of 0.2 μg PGE1 produced significant increases in core temperature in both nonpregnant and pregnant animals. The increase in core temperature, however, was attenuated both in magnitude and duration in pregnant compared with nonpregnant animals. After intracerebroventricular administration of a vasopressin V1-receptor antagonist, intracerebroventricular administration of 0.2 μg PGE1 produced significant increases in core temperature that were similar in nonpregnant and pregnant animals. Our data support the hypothesis that a pregnancy-related activation of AVP as an endogenous antipyretic substance in the central nervous system attenuates the febrile response to intracerebroventricular administration of PGE1 near term of pregnancy in rats.

scholarly journals Role of AVP in mediating the altered core temperature response to a simulated open field in pregnant rats

1999 ◽  
Vol 87 (1) ◽  
pp. 170-174
Author(s):  
Patricia A. Tang ◽  
James E. Fewell ◽  
Heather L. Eliason
Keyword(s):  
Receptor Antagonist ◽  
Open Field ◽  
Core Temperature ◽  
Arginine Vasopressin ◽  
Temperature Response ◽  
Pregnant Rats ◽  
Temperature Index ◽  
The Core ◽  
The Central Nervous System

Near the term of pregnancy, rats have an attenuated core temperature response on exposure to a novel environment (e.g., a simulated open field) compared with that observed early in pregnancy or in nonpregnant rats. The present experiments were carried out on 26 nonpregnant and 26 pregnant rats to test the hypothesis that arginine vasopressin, functioning as an endogenous antipyretic substance in the central nervous system, mediates this attenuated core temperature response. Exposure to a simulated open field after intracerebroventricular (ICV) vehicle produced a significant increase in core temperature in both nonpregnant and pregnant animals, the magnitude and duration of which were greater in the nonpregnant rats. In nonpregnant rats, exposure to a simulated open field after ICV vasopressin V1-receptor antagonist altered the pattern of the core temperature response but not the core temperature index compared with that observed on exposure to a simulated open field after ICV vehicle. In pregnant animals, ICV vasopressin V1-receptor antagonist did not alter the core temperature response to a simulated open field compared with that observed after ICV vehicle. Thus our data do not support the hypothesis that a pregnancy-related activation of arginine vasopressin attenuates the core temperature response to a simulated open field in rats near the term of pregnancy.

Body-core temperature decreases during hypoxic hypoxia in Long–Evans and Brattleboro rats

1994 ◽  
Vol 72 (12) ◽  
pp. 1528-1531 ◽  
Author(s):  
Deborah J. Clark ◽  
James E. Fewell
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Core Temperature ◽  
Arginine Vasopressin ◽  
Hypoxic Hypoxia ◽  
Body Core Temperature ◽  
Brattleboro Rats ◽  
Body Core ◽  
The Central Nervous System ◽  
Long Evans

In newborn mammals, hypoxic hypoxia produces a regulated decrease in body-core temperature, the mechanism of which is unknown. Since plasma and cerebrospinal fluid levels of arginine vasopressin increase during hypoxemia and intracerebroventricular administration of arginine vasopressin decreases body-core temperature, it has been hypothesized that an increase in central arginine vasopressin may mediate this response. Experiments were therefore carried out to test the hypothesis that the body-core temperature response to hypoxic hypoxia would be different in Brattleboro rats (which lack arginine vasopressin containing cells in the central nervous system) compared with that observed in Long–Evans rats (which have arginine vasopressin containing cells in the central nervous system). Both mild (15% oxygen) and severe (10% oxygen) hypoxic hypoxia decreased body-core temperature in both strains of rats, the decrease actually being accentuated in the Brattleboro rats. Thus, our data do not support the hypothesis that an increase in central arginine vasopressin mediates the regulated decrease in body-core temperature during hypoxic hypoxia in rats.Key words: hypoxic hypoxia, thermoregulation, arginine vasopressin, Brattleboro rats, Long–Evans rats.

scholarly journals Effects of Electroacupuncture on Pain Threshold of Laboring Rats and the Expression of Norepinephrine Transporter andα2 Adrenergic Receptor in the Central Nervous System

2016 ◽  
Vol 2016 ◽  
pp. 1-8
Author(s):  
Qianli Tang ◽  
Qiuyan Jiang ◽  
Suren R. Sooranna ◽  
Shike Lin ◽  
Yuanyuan Feng ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Adrenergic Receptor ◽  
Pain Threshold ◽  
Norepinephrine Transporter ◽  
Control Group ◽  
Tail Flick ◽  
Pregnant Rats ◽  
Tail Flick Test ◽  
The Central Nervous System

To observe the effects of electroacupuncture on pain threshold of laboring rats and the expression of norepinephrine transporter andα2 adrenergic receptor in the central nervous system to determine the mechanism of the analgesic effect of labor. 120 pregnant rats were divided into 6 groups: a control group, 4 electroacupuncture groups, and a meperidine group. After interventions, the warm water tail-flick test was used to observe pain threshold. NE levels in serum, NET, andα2AR mRNA and protein expression levels in the central nervous system were measured. No difference in pain threshold was observed between the 6 groups before intervention. After intervention, increased pain thresholds were observed in all groups except the control group with a higher threshold seen in the electroacupuncture groups. Serum NE levels decreased in the electroacupuncture and MP groups. Increases in NET andα2AR expression in the cerebral cortex and decreases in enlarged segments of the spinal cord were seen. Acupuncture increases uptake of NE via cerebral NET and decreases its uptake by spinal NET. The levels ofα2AR are also increased and decreased, respectively, in both tissues. This results in a decrease in systemic NE levels and may be the mechanism for its analgesic effects.

Body temperature response to IL-1 beta in pregnant rats

1995 ◽  
Vol 269 (5) ◽  
pp. R1179-R1182 ◽  
Author(s):  
R. L. Simrose ◽  
J. E. Fewell
Keyword(s):  
Body Temperature ◽  
Intravenous Injection ◽  
Interleukin 1 ◽  
Temperature Response ◽  
Sprague Dawley ◽  
Endogenous Pyrogen ◽  
Febrile Response ◽  
Pregnant Rats ◽  
Sprague Dawley Rats ◽  
Near Term

Rats have an attenuated or absent febrile response to exogenous pyrogen (e.g., bacterial endotoxin) near term of pregnancy. With the aim of providing insight into possible mechanism(s) of the altered febrile response to exogenous pyrogen, experiments have been carried out on 67 time-bred Sprague-Dawley rats to investigate the febrile response to endogenous pyrogen [i.e., interleukin-1 beta (IL-1 beta)]. On day 13 of gestation, intravenous injection of IL-1 beta produced a significant increase in body temperature with a latency of approximately 30 min and a duration of approximately 120 min. In contrast, on days 17 and 21 of gestation as well as on the day of delivery, intravenous injection of IL-1 beta produced significant decreases in body temperature. Thus rats do not develop fever in response to endogenous pyrogen near term of pregnancy but rather become hypothermic. The mechanism of the altered body temperature response to exogenous pyrogen as pregnancy proceeds remains unknown. We speculate, however, that it most likely lies downstream from the formation of endogenous pyrogen.

Peri-OVLT E-series prostaglandins and core temperature do not increase after intravenous IL-1β in pregnant rats

2002 ◽  
Vol 93 (2) ◽  
pp. 531-536 ◽  
Author(s):  
James E. Fewell ◽  
Heather L. Eliason ◽  
Roland N. Auer
Keyword(s):  
Core Temperature ◽  
Intravenous Administration ◽  
Sprague Dawley ◽  
Endogenous Pyrogen ◽  
Febrile Response ◽  
Pregnant Rats ◽  
Organum Vasculosum Laminae Terminalis ◽  
Sprague Dawley Rats ◽  
Maternal Adaptation ◽  
Near Term

Rats have an attenuated febrile response to endogenous pyrogen near the term of pregnancy. Given the fundamental role of E-series prostaglandins (PGEs) in mediating the febrile response to blood-borne endogenous pyrogen, the present experiments were carried out to determine whether PGEs increase in the area surrounding the organum vasculosum laminae terminalis (peri-OVLT) of near-term pregnant (P) rats as in nonpregnant (NP) rats after intravenous (iv) administration of recombinant rat interleukin-1β (rrIL-1β). Core temperature was measured by telemetry and peri-OVLT interstitial fluid was sampled in 12 NP and 12 P chronically instrumented, Sprague-Dawley rats by microdialysis for determination of total PGEs by radioimmunoassay. Basal core temperatures were higher in NP compared with P rats (NP 37.9°C ± 0.5, P 36.9°C ± 0.4; P < 0.05), but basal peri-OVLT PGEs were similar in both groups (NP 260 ± 153 pg/ml, P 278 ± 177 pg/ml; P =not significant). Intravenous administration of rrIL-1β to NP rats produced a significant increase in core temperature with a latency, magnitude, and duration of 10 min, 0.87°C, and at least 170 min, respectively; peri-OVLT PGEs were increased significantly by 30 min and averaged 270% above basal levels throughout the experiment. In P rats, however, neither core temperature nor peri-OVLT PGEs increased significantly after iv administration of rrIL-1β. Intravenous administration of vehicle did not significantly alter core temperature or peri-OVLT PGEs in either group of rats. Thus peri-OVLT PGEs do not increase in P rats as they do in NP rats after iv administration of rrIL-1β. The mechanism of this interesting component of the maternal adaptation to pregnancy, which likely plays a major role in mediating the attenuated febrile response to endogenous pyrogen near the term of pregnancy, warrants further investigation.

scholarly journals Effect of suramin, a P2 receptor antagonist, on the central nervous system.

1996 ◽  
Vol 71 ◽  
pp. 263
Author(s):  
Seiji Hori ◽  
Kunie Kamata ◽  
Yasushi Noguchi ◽  
Junko Sato ◽  
Mikio Nakamura ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Receptor Antagonist ◽  
P2 Receptor ◽  
The Central Nervous System
Sign in / Sign up

Export Citation Format

Share Document