Estrogen modulates central and peripheral responses to cold in female rats

Uchida, Yuzo; Kano, Masumi; Yasuhara, Saki; Kobayashi, Akiko; Tokizawa, Ken; Nagashima, Kei

doi:10.1007/s12576-009-0079-x

Cited by 25 publications

(23 citation statements)

References 39 publications

(52 reference statements)

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“…In addition, the sympathetic nerve stimulates brown adipose tissue to cause non-shivering thermogenesis. It is reported that estrogen acts on the hypothalamus and brown adipose tissue and affects thermoregulation (9,29). In the present study, changes in central body temperature during general anesthesia were observed.…”

Section: Discussionsupporting

confidence: 50%

Effects of Intravenous Amino Acids on Anesthesia-Induced Hypothermia in Ovariectomized Rats

Ando

Kanazawa

Tsuda

et al. 2012

J Nutr Sci Vitaminol

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Summary A decrease in core temperature during general anesthesia is attenuated by infusion of an intravenous amino acid mixture. The purpose of the present study was to investigate the influence of physical and endocrine changes caused by ovariectomy on the inhibitory effect of amino acid infusion on anesthesia-induced hypothermia. Sprague-Dawley female rats were divided into a sham-operated (Sham) group and an ovariectomized (OVX) group. Saline solution or an amino acid mixture solution was infused for 180 min during sevoflurane anesthesia, and the rectal temperature was measured (4 groups). Intraperitoneal white adipose tissue mass, bilateral gastrocnemius weight and plasma insulin levels were measured. In the Sham rats, no inhibitory effect of the amino acid mixture on anesthesia-induced hypothermia was found, while in the OVX rats, hypothermia was significantly decreased. The intraperitoneal fat weight/body weight ratio was significantly higher in the OVX rats than in the Sham rats, but the gastrocnemius weight/body weight ratio was not significantly different. After amino acid infusion, the plasma insulin level was significantly higher in the OVX rats than in the Sham rats. In conclusion, our findings suggest that, in rats, ovarian function or female hormone affects protein turnover mediated by increase in insulin secretion and, thus, decreases the inhibitory effect of an infusion of amino acid mixture on anesthesia-induced hypothermia. Key Words hypothermia, amino acids, general anesthesia, ovariectomy Redistribution hypothermia occurs in the body after induction of general anesthesia. Core body temperature gradually declines as heat is lost from the body surface, and heat production slows because of decreased metabolism. Selldén et al. reported that an amino acid infusion during anesthesia caused nutrient-induced thermogenesis (NIT), preventing the temperature reduction of redistribution hypothermia ( 1 ). Fujiwara et al. noted a similar effect after amino acid infusion but not after an infusion of glucose and fat emulsion ( 2 ). It is known that the metabolism of amino acids requires a large expenditure of energy ( 3 ), and protein synthesis induced by amino acids has been shown to correlate positively with energy expenditure ( 4 ). When rats were given the protein synthesis inhibitor puromycin, NIT did not occur after amino acid infusion ( 5 ). It has also been suggested that 75% of the increased oxygen uptake by amino acid infusion is produced in tissues other than the internal organs ( 6 ). Amino acid infusion during general anesthesia was found to stimulate protein synthesis in skeletal muscle via enhanced insulin secretion and to prevent hypothermia by heat accumulation through NIT ( 7 ). We have reported that skeletal muscle and plasma insulin levels play a major role in changes in body temperature during general anesthesia and the effect of amino acids on body temperature in a rat model of muscle atrophy ( 8 ).On the other hand, sex hormone is known to be involved in thermoregulation. In addition,...

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Section: Discussionsupporting

confidence: 50%

Effects of Intravenous Amino Acids on Anesthesia-Induced Hypothermia in Ovariectomized Rats

Ando

Kanazawa

Tsuda

et al. 2012

J Nutr Sci Vitaminol

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“…Uchida et al assessed the effect of estradiol on thermoregulation by comparing ovariectomized rats that did and did not receive estradiol replacement. They suggested that estradiol lessens the reduction in core temperature during cold exposure by affecting autonomic and behavioral thermoregulatory processes [13,14]. The influence of estradiol on heart rates has also been reported in female rats: they demonstrate tachycardia after the depletion of plasma estradiol [15][16][17][18].…”

Section: Introductionmentioning

confidence: 94%

“…Depletion of plasma estradiol and progesterone starts within an hour after surgical removal of the ovaries in rats [23]. To assess the influence of estradiol depletion, previous studies have compared ovariectomized animals to sham-operated/estradiol-dosed animals [13,14,24] or investigated animals with genetic depletion of estradiol or estradiol receptors [25]. However, these studies could not clarify the time-effect after the estradiol depletion.…”

Section: Introductionmentioning

confidence: 99%

Daily Changes of Body Temperature and Heart Rate are Modulated after Estradiol Depletion in Female Rats

Marui¹

2016

Anat Physiol

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We assessed the influence of estradiol depletion on daily changes of core temperature, spontaneous activity, and heart rate in female rats. In addition, we evaluated the effects of estradiol depletion on β-adrenoreceptors (AR) in the heart and plasma norepinephrine. Rats were bilaterally ovariectomized and two tubes that either contained estradiol (E2) or were empty (C) were placed subcutaneously in each rat's abdominal cavity. The tubes were removed 10 days later. Core temperature and heart rates were continuously measured by biotelemetry before and 1, 7, and 21 days after removal of the tubes (PRE and Days 1, 7, and 21). Core temperature was higher in the E2 group than in the C group at 2330-0130 h on PRE and on Days 1-21. Core temperature exceeded the PRE level in the E2 group at 1430-1830 h on Days 1-21. Heart rates were lower in the E2 group than the C group throughout the day on PRE and on Days 1-21. β1-AR expression and plasma norepinephrine levels were lower in the E2 group than in the C group on PRE. Heart rates in the E2 group exceeded the PRE level on Days 1-21. We concluded that the depletion of plasma estradiol modulates daily changes of core temperature and heart rate, an effect that occurs immediately after the estradiol depletion. In addition, plasma norepinephrine and β-AR in the heart may at least partially affect heart rate. A n a to my & P h y s io logy: C u r r e n t Re sea rc h

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“…Molecular mechanisms of impaired adaptive thermogenesis in Pacap-deficient mice following cold exposure Molecular experiments were performed only on male mice, as estrous cycle patterns and sexual hormones in female rodents are known to impact thermoregulatory responses (Bu & Lephart 2005, Uchida et al 2010. This experiment was conducted in two independent batches of male Pacap K/K and Pacap , 4 8C) as described above.…”

Section: Experimental Procedures Ne-induced Thermogenesis Inmentioning

confidence: 99%

PACAP is essential for the adaptive thermogenic response of brown adipose tissue to cold exposure

Diané¹,

Nikolic²,

Rudecki³

et al. 2014

Journal of Endocrinology

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Pituitary adenylate cyclase-activating polypeptide (PACAP) is a widely distributed neuropeptide that acts as a neurotransmitter, neuromodulator, neurotropic factor, neuroprotectant, secretagogue, and neurohormone. Owing to its pleiotropic biological actions, knockout of Pacap (Adcyap1) has been shown to induce several abnormalities in mice such as impaired thermoregulation. However, the underlying physiological and molecular mechanisms remain unclear. A previous report has shown that cold-exposed Pacap null mice cannot supply appropriate levels of norepinephrine (NE) to brown adipocytes. Therefore, we hypothesized that exogenous NE would rescue the impaired thermogenic response of Pacap null mice during cold exposure. We compared the adaptive thermogenic capacity of Pacap K/K to Pacap C/C mice in response to NE when housed at room temperature (24 8C) and after a 3.5-week cold exposure (4 8C). Biochemical parameters, expression of thermogenic genes, and morphological properties of brown adipose tissue (BAT) and white adipose tissue (WAT) were also characterized. Results showed that there was a significant effect of temperature, but no effect of genotype, on the resting metabolic rate in conscious, unrestrained mice. However, the normal cold-induced increase in the basal metabolic rate and NE-induced increase in thermogenesis were severely blunted in cold-exposed Pacap K/K mice. These changes were associated with altered substrate utilization, reduced b 3 -adrenergic receptor (b 3 -Ar (Adrb3)) and hormone-sensitive lipase (Hsl (Lipe)) gene expression, and increased fibroblast growth factor 2 (Fgf2) gene expression in BAT. Interestingly, Pacap K/K mice had depleted WAT depots, associated with upregulated uncoupling protein 1 expression in inguinal WATs. These results suggest that the impairment of adaptive thermogenesis in Pacap null mice cannot be rescued by exogenous NE perhaps in part due to decreased b 3 -Ar-mediated BAT activation.

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Estrogen modulates central and peripheral responses to cold in female rats

Cited by 25 publications

References 39 publications

Effects of Intravenous Amino Acids on Anesthesia-Induced Hypothermia in Ovariectomized Rats

Effects of Intravenous Amino Acids on Anesthesia-Induced Hypothermia in Ovariectomized Rats

Daily Changes of Body Temperature and Heart Rate are Modulated after Estradiol Depletion in Female Rats

PACAP is essential for the adaptive thermogenic response of brown adipose tissue to cold exposure

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