Attenuation of metabolic heat production and cold-escape/warm-seeking behaviour during a cold exposure following systemic salt loading in rats

Masahiro Konishi, Kei Nagashima, Kento Asano, Kazuyuki Kanosue

Research output: Contribution to journalArticle

14 Citations (Scopus)

Abstract

The reduction of body core temperature (Tcore) after salt loading has been reported. In this study, we tested the hypothesis that, during a cold exposure in rats, (1) salt loading would decrease metabolic rate (MR), reducing Tcore but (2) Tcore would be maintained when cold-escape/warm-seeking behaviour is available. In the first experiment (n = 7), MR and Tcore were measured by indirect calorimetry and telemetry, respectively, during 26, 20 and 10 °C exposure for 1 h each, in that order. In the second experiment (n = 7), each rat was placed in an operant system during the same exposure protocol as in the first experiment, where it could trigger a 40 °C air reward for 30 s at 20 and 10 °C by moving into specific areas (operant behaviour). In each experiment, rats repeated the same protocol twice with a subcutaneous injection (10 ml kg-1) of either isotonic saline (154 mM) or hypertonic saline (2500 mM). In the first experiment, MR in the isotonic-saline trial increased (P < 0.05) at 20 and 10 °C compared with that at 26 °C by 21 ± 5 and 48 ± 6%, respectively (means ± S.E.M.), with Tcore unchanged. However, values for MR and Tcore in the hypertonic-saline trial were lower (P < 0.05) than those in the isotonic-saline trial in any ambient temperature. In the second experiment, Tcore was also lower (P < 0.05) in the hypertonic-saline trial than in the isotonic-saline trial. The counts of the operant behaviour in the hypertonic-saline trial remained unchanged in each exposure period, but those in the isotonic-saline trial increased (P < 0.05) at 10 °C. These results may suggest that salt loading attenuates both metabolic and behavioural thermoregulatory responses to the cold.

Original languageEnglish
Pages (from-to)713-720
Number of pages8
JournalJournal of Physiology
Volume551
Issue number2
DOIs
Publication statusPublished - 2003 Sep 1
Externally publishedYes

Fingerprint

Thermogenesis
Salts
Indirect Calorimetry
Telemetry
Subcutaneous Injections
Body Temperature
Reward
Air
Temperature

ASJC Scopus subject areas

  • Physiology

Cite this

Attenuation of metabolic heat production and cold-escape/warm-seeking behaviour during a cold exposure following systemic salt loading in rats. / Konishi, Masahiro; Nagashima, Kei; Asano, Kento; Kanosue, Kazuyuki.

In: Journal of Physiology, Vol. 551, No. 2, 01.09.2003, p. 713-720.

Research output: Contribution to journalArticle

@article{ec8235537e6e4eb0a478bd8b7275b963,
title = "Attenuation of metabolic heat production and cold-escape/warm-seeking behaviour during a cold exposure following systemic salt loading in rats",
abstract = "The reduction of body core temperature (Tcore) after salt loading has been reported. In this study, we tested the hypothesis that, during a cold exposure in rats, (1) salt loading would decrease metabolic rate (MR), reducing Tcore but (2) Tcore would be maintained when cold-escape/warm-seeking behaviour is available. In the first experiment (n = 7), MR and Tcore were measured by indirect calorimetry and telemetry, respectively, during 26, 20 and 10 °C exposure for 1 h each, in that order. In the second experiment (n = 7), each rat was placed in an operant system during the same exposure protocol as in the first experiment, where it could trigger a 40 °C air reward for 30 s at 20 and 10 °C by moving into specific areas (operant behaviour). In each experiment, rats repeated the same protocol twice with a subcutaneous injection (10 ml kg-1) of either isotonic saline (154 mM) or hypertonic saline (2500 mM). In the first experiment, MR in the isotonic-saline trial increased (P < 0.05) at 20 and 10 °C compared with that at 26 °C by 21 ± 5 and 48 ± 6{\%}, respectively (means ± S.E.M.), with Tcore unchanged. However, values for MR and Tcore in the hypertonic-saline trial were lower (P < 0.05) than those in the isotonic-saline trial in any ambient temperature. In the second experiment, Tcore was also lower (P < 0.05) in the hypertonic-saline trial than in the isotonic-saline trial. The counts of the operant behaviour in the hypertonic-saline trial remained unchanged in each exposure period, but those in the isotonic-saline trial increased (P < 0.05) at 10 °C. These results may suggest that salt loading attenuates both metabolic and behavioural thermoregulatory responses to the cold.",
author = "Masahiro Konishi and Kei Nagashima and Kento Asano and Kazuyuki Kanosue",
year = "2003",
month = "9",
day = "1",
doi = "10.1113/jphysiol.2003.040592",
language = "English",
volume = "551",
pages = "713--720",
journal = "Journal of Physiology",
issn = "0022-3751",
publisher = "Wiley-Blackwell",
number = "2",

}

TY - JOUR

T1 - Attenuation of metabolic heat production and cold-escape/warm-seeking behaviour during a cold exposure following systemic salt loading in rats

AU - Konishi, Masahiro

AU - Nagashima, Kei

AU - Asano, Kento

AU - Kanosue, Kazuyuki

PY - 2003/9/1

Y1 - 2003/9/1

N2 - The reduction of body core temperature (Tcore) after salt loading has been reported. In this study, we tested the hypothesis that, during a cold exposure in rats, (1) salt loading would decrease metabolic rate (MR), reducing Tcore but (2) Tcore would be maintained when cold-escape/warm-seeking behaviour is available. In the first experiment (n = 7), MR and Tcore were measured by indirect calorimetry and telemetry, respectively, during 26, 20 and 10 °C exposure for 1 h each, in that order. In the second experiment (n = 7), each rat was placed in an operant system during the same exposure protocol as in the first experiment, where it could trigger a 40 °C air reward for 30 s at 20 and 10 °C by moving into specific areas (operant behaviour). In each experiment, rats repeated the same protocol twice with a subcutaneous injection (10 ml kg-1) of either isotonic saline (154 mM) or hypertonic saline (2500 mM). In the first experiment, MR in the isotonic-saline trial increased (P < 0.05) at 20 and 10 °C compared with that at 26 °C by 21 ± 5 and 48 ± 6%, respectively (means ± S.E.M.), with Tcore unchanged. However, values for MR and Tcore in the hypertonic-saline trial were lower (P < 0.05) than those in the isotonic-saline trial in any ambient temperature. In the second experiment, Tcore was also lower (P < 0.05) in the hypertonic-saline trial than in the isotonic-saline trial. The counts of the operant behaviour in the hypertonic-saline trial remained unchanged in each exposure period, but those in the isotonic-saline trial increased (P < 0.05) at 10 °C. These results may suggest that salt loading attenuates both metabolic and behavioural thermoregulatory responses to the cold.

AB - The reduction of body core temperature (Tcore) after salt loading has been reported. In this study, we tested the hypothesis that, during a cold exposure in rats, (1) salt loading would decrease metabolic rate (MR), reducing Tcore but (2) Tcore would be maintained when cold-escape/warm-seeking behaviour is available. In the first experiment (n = 7), MR and Tcore were measured by indirect calorimetry and telemetry, respectively, during 26, 20 and 10 °C exposure for 1 h each, in that order. In the second experiment (n = 7), each rat was placed in an operant system during the same exposure protocol as in the first experiment, where it could trigger a 40 °C air reward for 30 s at 20 and 10 °C by moving into specific areas (operant behaviour). In each experiment, rats repeated the same protocol twice with a subcutaneous injection (10 ml kg-1) of either isotonic saline (154 mM) or hypertonic saline (2500 mM). In the first experiment, MR in the isotonic-saline trial increased (P < 0.05) at 20 and 10 °C compared with that at 26 °C by 21 ± 5 and 48 ± 6%, respectively (means ± S.E.M.), with Tcore unchanged. However, values for MR and Tcore in the hypertonic-saline trial were lower (P < 0.05) than those in the isotonic-saline trial in any ambient temperature. In the second experiment, Tcore was also lower (P < 0.05) in the hypertonic-saline trial than in the isotonic-saline trial. The counts of the operant behaviour in the hypertonic-saline trial remained unchanged in each exposure period, but those in the isotonic-saline trial increased (P < 0.05) at 10 °C. These results may suggest that salt loading attenuates both metabolic and behavioural thermoregulatory responses to the cold.

UR - http://www.scopus.com/inward/record.url?scp=0141857807&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0141857807&partnerID=8YFLogxK

U2 - 10.1113/jphysiol.2003.040592

DO - 10.1113/jphysiol.2003.040592

M3 - Article

C2 - 12815190

AN - SCOPUS:0141857807

VL - 551

SP - 713

EP - 720

JO - Journal of Physiology

JF - Journal of Physiology

SN - 0022-3751

IS - 2

ER -