1
|
Fonseca CS, Aquino NSS, Goncalves GKN, Drummond LR, Hipolito LTM, Silva JF, Silva KSC, Henriques PC, Domingues TE, Lacerda ACR, Guatimosim S, Coimbra CC, Szawka RE, Reis AM. Norepinephrine modulation of heat dissipation in female rats lacking estrogen. J Neuroendocrinol 2022; 34:e13188. [PMID: 36306200 DOI: 10.1111/jne.13188] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 06/10/2022] [Accepted: 07/15/2022] [Indexed: 11/27/2022]
Abstract
Postmenopausal hot flushes are caused by lack of estradiol (E2) but their neuroendocrine basis is still poorly understood. Here, we investigated the interrelationship between norepinephrine and hypothalamic neurons, with emphasis on kisspeptin neurons in the arcuate nucleus (ARC), as a regulatory pathway in the vasomotor effects of E2. Ovariectomized (OVX) rats displayed increased tail skin temperature (TST), and this increase was prevented in OVX rats treated with E2 (OVX + E2). Expression of Fos in the hypothalamus and the number of ARC kisspeptin neurons coexpressing Fos were increased in OVX rats. Likewise, brainstem norepinephrine neurons of OVX rats displayed higher Fos immunoreactivity associated with the increase in TST. In the ARC, the density of dopamine-ß-hydroxylase (DBH)-immunoreactive (ir) fibers was not altered by E2 but, importantly, DBH-ir terminals were found in close apposition to kisspeptin cells, revealing norepinephrine inputs to ARC kisspeptin neurons. Intracerebroventricular injection of the α2-adrenergic agonist clonidine (CLO) was used to reduce central norepinephrine release, confirmed by the decreased 3-methoxy-4-hydroxyphenylglycol/norepinephrine ratio in the preoptic area and ARC. Accordingly, CLO treatment in OVX rats reduced ARC Kiss1 mRNA levels and TST to the values of OVX + E2 rats. Conversely, CLO stimulated Kiss1 expression in the anteroventral periventricular nucleus (AVPV) and increased luteinizing hormone secretion. These findings provide evidence that augmented heat dissipation in OVX rats involves the increase in central norepinephrine that modulates hypothalamic areas related to thermoregulation, including ARC kisspeptin neurons. This neuronal network is suppressed by E2 and its imbalance may be implicated in the vasomotor symptoms of postmenopausal hot flushes.
Collapse
Affiliation(s)
- Cristina S Fonseca
- Departamento de Fisiologia e Biofisica, Instituto de Ciencias Biologicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Nayara S S Aquino
- Departamento de Fisiologia e Biofisica, Instituto de Ciencias Biologicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Gleisy K N Goncalves
- Departamento de Fisiologia e Biofisica, Instituto de Ciencias Biologicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Lucas R Drummond
- Departamento de Fisiologia e Biofisica, Instituto de Ciencias Biologicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Laisa T M Hipolito
- Departamento de Fisiologia e Biofisica, Instituto de Ciencias Biologicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Juneo F Silva
- Centro de Microscopia Eletronica, Departamento de Ciencias Biologicas, Universidade Estadual de Santa Cruz, Ilheus, Brazil
| | - Kaoma S C Silva
- Departamento de Fisiologia e Biofisica, Instituto de Ciencias Biologicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Patricia C Henriques
- Departamento de Fisiologia e Biofisica, Instituto de Ciencias Biologicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Talita E Domingues
- Faculdade de Ciencias Biologicas e da Saude, Universidade Federal dos Vales do Jequitinhonha e Mucuri, Diamantina, Brazil
| | - Ana C R Lacerda
- Faculdade de Ciencias Biologicas e da Saude, Universidade Federal dos Vales do Jequitinhonha e Mucuri, Diamantina, Brazil
| | - Silvia Guatimosim
- Departamento de Fisiologia e Biofisica, Instituto de Ciencias Biologicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Candido C Coimbra
- Departamento de Fisiologia e Biofisica, Instituto de Ciencias Biologicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Raphael E Szawka
- Departamento de Fisiologia e Biofisica, Instituto de Ciencias Biologicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Adelina M Reis
- Departamento de Fisiologia e Biofisica, Instituto de Ciencias Biologicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| |
Collapse
|
2
|
Marui S, Masuda Y, Kato I, Nagashima K. Influence of exogenous and endogenous estrogen on thermoregulatory responses to mild heat and the interaction with light and dark phases. J Physiol Sci 2020; 70:56. [PMID: 33256597 PMCID: PMC10717522 DOI: 10.1186/s12576-020-00782-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 11/11/2020] [Indexed: 11/10/2022]
Abstract
The present study aimed to determine the influence of estradiol (E2) and the interaction with circadian phases on thermoregulatory responses to mild heat in female rats. Heat loss and production during 3-h exposure to the environment at an ambient temperature of 28-34 °C were assessed by measuring abdominal temperature (Tabd), tail skin temperature, and oxygen consumption in ovariectomized rats with and without E2 replacement (OVX + E2 and OVX, respectively) and in control rats in the proestrus (P) and diestrus (D) phases. In the light phase, Tabd remained unchanged in all groups. Tabd increased in the dark phase, but was lower in the OVX + E2 and P groups than in the OVX and D groups. Oxygen consumption decreased at 34 °C, but to a lesser extent in the OVX + E2 group than in the OVX group. These results suggest that E2 activates thermoregulation in mild heat in the dark phase.
Collapse
Affiliation(s)
- Shuri Marui
- Body Temperature and Fluid Laboratory, Faculty of Human Sciences, Waseda University, Mikajima 2-579-15, Tokorozawa, Saitama, 359-1192, Japan
| | - Yuta Masuda
- Body Temperature and Fluid Laboratory, Faculty of Human Sciences, Waseda University, Mikajima 2-579-15, Tokorozawa, Saitama, 359-1192, Japan
- Graduate School of Human Sciences, Faculty of Human Sciences, Waseda University, Tokorozawa, Japan
| | - Issei Kato
- Body Temperature and Fluid Laboratory, Faculty of Human Sciences, Waseda University, Mikajima 2-579-15, Tokorozawa, Saitama, 359-1192, Japan
- Graduate School of Human Sciences, Faculty of Human Sciences, Waseda University, Tokorozawa, Japan
| | - Kei Nagashima
- Body Temperature and Fluid Laboratory, Faculty of Human Sciences, Waseda University, Mikajima 2-579-15, Tokorozawa, Saitama, 359-1192, Japan.
| |
Collapse
|
3
|
Hairi HA, Shuid AN, Ibrahim N‘I, Jamal JA, Mohamed N, Mohamed IN. The Effects and Action Mechanisms of Phytoestrogens on Vasomotor Symptoms During Menopausal Transition: Thermoregulatory Mechanism. Curr Drug Targets 2018; 20:192-200. [DOI: 10.2174/1389450118666170816123740] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Revised: 07/14/2017] [Accepted: 07/26/2017] [Indexed: 01/07/2023]
Abstract
Background:
Phytoestrogens have recently been claimed to positively influence menopausal
discomforts, including hot flashes. However, little is known about the influence of phytoestrogens
on core body temperature during oestrogen fluctuation at menopause.
Objective:
Previously published findings showed that phytoestrogens could relieve menopausal complaints,
thus, the present review was aimed at assessing the effects of phytoestrogens on thermoregulatory
mechanism during menopausal transition.
Results:
The molecular mechanisms underlying hot flashes are complex. Oestrogen fluctuations cause
hypothalamic thermoregulatory centre dysfunction, which leads to hot flashes during menopause. The
phytoestrogens of interest, in relation to human health, include isoflavones, lignans, coumestans, and
stilbenes, which are widely distributed in nature. The phytoestrogens are capable of reducing hot
flashes via their oestrogen-like hormone actions. The potential effects of phytoestrogens on hot flashes
and their molecular mechanisms of action on thermoregulatory centre are discussed in this review.
Conclusion:
The effects of phytoestrogens on these mechanisms may help explain their beneficial effects
in alleviating hot flashes and other menopausal discomforts.
Collapse
Affiliation(s)
- Haryati Ahmad Hairi
- Department of Pharmacology, Faculty of Medicine, Preclinical Building, Universiti Kebangsaan Malaysia, Jalan Yaacob Latiff, Bandar Tun Razak, Cheras, 56000 Kuala Lumpur, Malaysia
| | - Ahmad Nazrun Shuid
- Department of Pharmacology, Faculty of Medicine, Preclinical Building, Universiti Kebangsaan Malaysia, Jalan Yaacob Latiff, Bandar Tun Razak, Cheras, 56000 Kuala Lumpur, Malaysia
| | - Nurul ‘Izzah Ibrahim
- Department of Biomedical Science, Faculty of Science, Lincoln University College, Jalan Stadium, SS 7/15, Kelana Jaya, 47301 Petaling Jaya, Selangor, Malaysia
| | - Jamia Azdina Jamal
- Faculty of Pharmacy, Universiti Kebangsaan Malaysia, Jalan Raja Abdul Aziz, 50300 Kuala Lumpur, Malaysia
| | - Norazlina Mohamed
- Department of Pharmacology, Faculty of Medicine, Preclinical Building, Universiti Kebangsaan Malaysia, Jalan Yaacob Latiff, Bandar Tun Razak, Cheras, 56000 Kuala Lumpur, Malaysia
| | - Isa Naina Mohamed
- Department of Pharmacology, Faculty of Medicine, Preclinical Building, Universiti Kebangsaan Malaysia, Jalan Yaacob Latiff, Bandar Tun Razak, Cheras, 56000 Kuala Lumpur, Malaysia
| |
Collapse
|
4
|
Sun Y, Qin LH, Chen X, Yan X, Mao L, Bai W, Kang J. Effects of black cohosh and estrogen on core body and tail-skin temperatures in ovariectomized rats by telemetric monitoring with dual thermistor probes. Climacteric 2018; 21:153-159. [PMID: 29323578 DOI: 10.1080/13697137.2017.1415320] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
OBJECTIVES To investigate the effects of black cohosh and estrogen on the temperature in ovariectomized rats, the core body temperature (CBT) and tail-skin temperature (TST) were simultaneously monitored and the relationship between these two temperatures was explored. METHODS Twenty-four female Sprague-Dawley rats aged 8 weeks were randomly divided into four groups: sham-operated (SHAM), ovariectomized (OVX), OVX treated with estradiol valerate (OVX + E), and OVX treated with isopropanolic black cohosh extract (OVX + ICR). Rats were sham-operated or ovariectomized and were implanted with telemetry transmitters with dual thermistor probes. Two weeks after surgery, the animals were treated with drugs for 4 weeks. During the last week of the treatments, the dynamic temperature profiles of the CBT and TST were collected. RESULTS The average CBT and TST, TST fluctuation frequency, and the average amplitude fluctuation were significantly higher in OVX than in SHAM rats. In addition, dramatic fluctuations of TST in OVX rats occurred at the time points of the day when the CBTs were lower in OVX rats than in SHAM rats. Treatment of OVX rats with estradiol valerate or isopropanolic black cohosh extract markedly decreased the average CBT and TST, TST fluctuation frequency, and the average amplitude fluctuation. Moreover, CBT was found to be significantly higher, while TST was lower in OVX + E than in OVX + ICR rats. CONCLUSIONS Both black cohosh and estradiol treatments ameliorated the abnormal thermoregulation in OVX rats. In particular, black cohosh reduced CBT better than estradiol and estradiol reduced TST better than black cohosh.
Collapse
Affiliation(s)
- Y Sun
- a Department of Obstetrics and Gynecology , Beijing Shijitan Hospital, Capital Medical University , Beijing , China
| | - L H Qin
- b Department of Anatomy and Embryology , Peking University Health Science Center , Beijing , China
| | - X Chen
- c Department of Obstetrics and Gynecology , Peking University First Hospital , Beijing , China
| | - X Yan
- d Department of Clinical Research Institute , Peking University Health Science Center , Beijing , China
| | - L Mao
- c Department of Obstetrics and Gynecology , Peking University First Hospital , Beijing , China
| | - W Bai
- a Department of Obstetrics and Gynecology , Beijing Shijitan Hospital, Capital Medical University , Beijing , China
| | - J Kang
- e Department of Physiology and Pathophysiology, School of Basic Medical Sciences , Peking University Health Science Center , Beijing , China
| |
Collapse
|
5
|
Krajewski-Hall SJ, Blackmore EM, McMinn JR, Rance NE. Estradiol alters body temperature regulation in the female mouse. Temperature (Austin) 2017; 5:56-69. [PMID: 29687044 DOI: 10.1080/23328940.2017.1384090] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2017] [Revised: 09/18/2017] [Accepted: 09/18/2017] [Indexed: 10/18/2022] Open
Abstract
Hot flushes are due to estrogen withdrawal and characterized by the episodic activation of heat dissipation effectors. Recent studies (in humans and rats) have implicated neurokinin 3 (NK3) receptor signaling in the genesis of hot flushes. Although transgenic mice are increasingly used for biomedical research, there is limited information on how 17β-estradiol and NK3 receptor signaling alters thermoregulation in the mouse. In this study, a method was developed to measure tail skin temperature (TSKIN) using a small data-logger attached to the surface of the tail, which, when combined with a telemetry probe for core temperature (TCORE), allowed us to monitor thermoregulation in freely-moving mice over long durations. We report that estradiol treatment of ovariectomized mice reduced TCORE during the light phase (but not the dark phase) while having no effect on TSKIN or activity. Estradiol also lowered TCORE in mice exposed to ambient temperatures ranging from 20 to 36°C. Unlike previous studies in the rat, estradiol treatment of ovariectomized mice did not reduce TSKIN during the dark phase. Subcutaneous injections of an NK3 receptor agonist (senktide) in ovariectomized mice caused an acute increase in TSKIN and a reduction in TCORE, consistent with the activation of heat dissipation effectors. These changes were reduced by estradiol, suggesting that estradiol lowers the sensitivity of central thermoregulatory pathways to NK3 receptor activation. Overall, we show that estradiol treatment of ovariectomized mice decreases TCORE during the light phase, reduces the thermoregulatory effects of senktide and modulates thermoregulation differently than previously described in the rat.
Collapse
Affiliation(s)
- Sally J Krajewski-Hall
- Departments of Pathology (S.J.K-H., E.M.B., J.R.M. and N.E.R.), Cellular and Molecular Medicine (N.E.R.), Neurology (N.E.R.) and the Evelyn F. McKnight Brain Institute (N.E.R.) University of Arizona College of Medicine, Tucson, AZ, USA
| | - Elise M Blackmore
- Departments of Pathology (S.J.K-H., E.M.B., J.R.M. and N.E.R.), Cellular and Molecular Medicine (N.E.R.), Neurology (N.E.R.) and the Evelyn F. McKnight Brain Institute (N.E.R.) University of Arizona College of Medicine, Tucson, AZ, USA
| | - Jessi R McMinn
- Departments of Pathology (S.J.K-H., E.M.B., J.R.M. and N.E.R.), Cellular and Molecular Medicine (N.E.R.), Neurology (N.E.R.) and the Evelyn F. McKnight Brain Institute (N.E.R.) University of Arizona College of Medicine, Tucson, AZ, USA
| | - Naomi E Rance
- Departments of Pathology (S.J.K-H., E.M.B., J.R.M. and N.E.R.), Cellular and Molecular Medicine (N.E.R.), Neurology (N.E.R.) and the Evelyn F. McKnight Brain Institute (N.E.R.) University of Arizona College of Medicine, Tucson, AZ, USA
| |
Collapse
|
6
|
Incorporation of capillary microsampling into whole body plethysmography and modified Irwin safety pharmacology studies in rats. Regul Toxicol Pharmacol 2015; 73:19-26. [DOI: 10.1016/j.yrtph.2015.06.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Revised: 06/01/2015] [Accepted: 06/02/2015] [Indexed: 11/22/2022]
|
7
|
Chapon PA, Bulla J, Gauthier A, Moussay S. On the importance of telemetric temperature sensor location during intraperitoneal implantation in rats. Lab Anim 2014; 48:114-23. [PMID: 24585934 DOI: 10.1177/0023677214522035] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
This study aims to assess the thermal homogeneity of the intraperitoneal (IP) cavity and the relevance of using a fixed telemetric temperature sensor at a given location in studying rodents. Ten rats were intraperitoneally implanted with three Jonah® capsules each; after assessing the accuracy and reliability of the sensors. Two capsules were attached, one to the right iliac fossa (RIF) and the other to the left hypochondrium (LH), and another was placed between the intestines but not attached (Free). In the ex vivo condition, the differences between sensors and reference values remained in the range of ±0.1. In the in vivo condition, each sensor enabled the observation of temperature patterns. However, sensor location affected mean and median temperature values while the rats were moving freely. Indeed, temperature data collected in the LH were 0.1 significantly higher than those collected in the RIF and temperature data collected in the LH were 0.11 significantly higher than those collected with the Free capsules. In in vivo conditions, intra-sensor variability of temperature data was not affected by sensor location. Taking into account sensor accuracy, similar intra-sensor variability, and mean differences observed between the three locations, the impact of sensor location within the IP cavity could be considered negligible. In in vivo conditions, temperature differences between locations regularly exceeded ±0.2 and reached up to 2.5. These extreme values could be explained by behavioral factors such as food or water intake. Finally, considering the good thermal homogeneity of the IP cavity and possible adverse consequences of sensor attachment, it seems better to let sensors range free within the cavity.
Collapse
|
8
|
Ishiwata T. Role of serotonergic system in thermoregulation in rats. JOURNAL OF PHYSICAL FITNESS AND SPORTS MEDICINE 2014. [DOI: 10.7600/jpfsm.3.445] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
9
|
Rance NE, Dacks PA, Mittelman-Smith MA, Romanovsky AA, Krajewski-Hall SJ. Modulation of body temperature and LH secretion by hypothalamic KNDy (kisspeptin, neurokinin B and dynorphin) neurons: a novel hypothesis on the mechanism of hot flushes. Front Neuroendocrinol 2013; 34:211-27. [PMID: 23872331 PMCID: PMC3833827 DOI: 10.1016/j.yfrne.2013.07.003] [Citation(s) in RCA: 201] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2013] [Revised: 07/09/2013] [Accepted: 07/12/2013] [Indexed: 12/31/2022]
Abstract
Despite affecting millions of individuals, the etiology of hot flushes remains unknown. Here we review the physiology of hot flushes, CNS pathways regulating heat-dissipation effectors, and effects of estrogen on thermoregulation in animal models. Based on the marked changes in hypothalamic kisspeptin, neurokinin B and dynorphin (KNDy) neurons in postmenopausal women, we hypothesize that KNDy neurons play a role in the mechanism of flushes. In the rat, KNDy neurons project to preoptic thermoregulatory areas that express the neurokinin 3 receptor (NK3R), the primary receptor for NKB. Furthermore, activation of NK₃R in the median preoptic nucleus, part of the heat-defense pathway, reduces body temperature. Finally, ablation of KNDy neurons reduces cutaneous vasodilatation and partially blocks the effects of estrogen on thermoregulation. These data suggest that arcuate KNDy neurons relay estrogen signals to preoptic structures regulating heat-dissipation effectors, supporting the hypothesis that KNDy neurons participate in the generation of flushes.
Collapse
Affiliation(s)
- Naomi E Rance
- Department of Pathology and the Evelyn F. McKnight Brain Research Institute, University of Arizona College of Medicine, Tucson, AZ 85724, USA.
| | | | | | | | | |
Collapse
|
10
|
Role for kisspeptin/neurokinin B/dynorphin (KNDy) neurons in cutaneous vasodilatation and the estrogen modulation of body temperature. Proc Natl Acad Sci U S A 2012; 109:19846-51. [PMID: 23150555 DOI: 10.1073/pnas.1211517109] [Citation(s) in RCA: 113] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Estrogen withdrawal in menopausal women leads to hot flushes, a syndrome characterized by the episodic activation of heat dissipation effectors. Despite the extraordinary number of individuals affected, the etiology of flushes remains an enigma. Because menopause is accompanied by marked alterations in hypothalamic kisspeptin/neurokinin B/dynorphin (KNDy) neurons, we hypothesized that these neurons could contribute to the generation of flushes. To determine if KNDy neurons participate in the regulation of body temperature, we evaluated the thermoregulatory effects of ablating KNDy neurons by injecting a selective toxin for neurokinin-3 expressing neurons [NK(3)-saporin (SAP)] into the rat arcuate nucleus. Remarkably, KNDy neuron ablation consistently reduced tail-skin temperature (T(SKIN)), indicating that KNDy neurons facilitate cutaneous vasodilatation, an important heat dissipation effector. Moreover, KNDy ablation blocked the reduction of T(SKIN) by 17β-estradiol (E(2)), which occurred in the environmental chamber during the light phase, but did not affect the E(2) suppression of T(SKIN) during the dark phase. At the high ambient temperature of 33 °C, the average core temperature (T(CORE)) of ovariectomized (OVX) control rats was significantly elevated, and this value was reduced by E(2) replacement. In contrast, the average T(CORE) of OVX, KNDy-ablated rats was lower than OVX control rats at 33 °C, and not altered by E(2) replacement. These data provide unique evidence that KNDy neurons promote cutaneous vasodilatation and participate in the E(2) modulation of body temperature. Because cutaneous vasodilatation is a cardinal sign of a hot flush, these results support the hypothesis that KNDy neurons could play a role in the generation of flushes.
Collapse
|
11
|
Ma X, Zhang H, Wang K, Yang L, Qin L, Bai W, Guan Y, Jia J, Kang J, Zhou C. Effects of an isopropanolic-aqueous black cohosh extract on central body temperature of ovariectomized rats. JOURNAL OF ETHNOPHARMACOLOGY 2011; 138:156-161. [PMID: 21924343 DOI: 10.1016/j.jep.2011.08.076] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2011] [Revised: 08/22/2011] [Accepted: 08/30/2011] [Indexed: 05/31/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Black cohosh (Cimicifuga racemosa) is widely used in menopause symptoms strategy. AIM OF THE STUDY The aim of this study was to examine the effect of isopropanolic black cohosh extract (iCR) on the central body temperature (CBT) of ovariectomized rats (OVX) and elaborate its possible effects in alleviating menopause related hot flushes. MATERIALS AND METHODS 64 female Sprague-Dawley rats, weighing 230 ± 10g and aged 6-8 weeks, were divided into four groups: ovariectomy (OVX), sham, ovariectomy plus estradiol valerate (OVX+E), and ovariectomy plus iCR (OVX+ICR). The sham group underwent a sham surgery without ovariectomies, while the other three groups underwent bilateral ovariectomies under sterile conditions and a temperature implant was embedded in the abdominal cavity of all four groups. After 2-week recovery period, the temperature of all animals was monitored for 6 weeks. RESULTS CBT of four groups maintained a normal circadian rhythm, with a low day CBT and a high night CBT. CBTs of the sham group were lower than that of the other three groups. The day CBTs of the (OVX+E) group and (OVX+ICR) group were lower than that of the OVX group from day 2 and day 22 respectively. For the difference between day and night CBT, the sham group was smallest, while (OVX+E) and (OVX+ICR) groups were higher than that of OVX group. The amplitude of day and night CBT, CBT fluctuation frequency at 5 min intervals, were higher for the OVX group than the sham group; the amplitude of day and night CBT of (OVX+E) group and the amplitude of night CBT of (OVX+ICR) group were higher than those of OVX group; while the amplitude of day CBT of (OVX+ICR) group was lower than that of OVX group; CBT fluctuation frequency at 5 min intervals was higher for the (OVX+E) and (OVX+ICR) groups than the OVX group. CONCLUSIONS Ovariectomized rats had abnormal thermoregulation, demonstrating an increase in day and night CBT, greater difference between day and night CBT, higher amplitude of day and night CBT, and more CBT fluctuation frequency. For the herbal extract iCR, the onset of affecting abnormal thermoregulation took longer than that of estradiol valerate. ICR had a significant effect on day CBT but was only little effective on night CBT of ovariectomized rats.
Collapse
Affiliation(s)
- Xiaoyan Ma
- Department of Gynecology, The First Hospital of Peking University, Beijing, China
| | | | | | | | | | | | | | | | | | | |
Collapse
|
12
|
Williams H, Dacks PA, Rance NE. An improved method for recording tail skin temperature in the rat reveals changes during the estrous cycle and effects of ovarian steroids. Endocrinology 2010; 151:5389-94. [PMID: 20861232 PMCID: PMC2954718 DOI: 10.1210/en.2010-0630] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
In the rat, tail skin vasomotion is a primary heat loss mechanism that can be monitored by changes in tail skin temperature (T(SKIN)). Previous studies showed that ovariectomy and estrogen replacement modify T(SKIN) in the rat. Based on these findings, the ovariectomized (OVX) rat has been used as a model to study the mechanisms and treatment of menopausal hot flushes. It is not known, however, if T(SKIN) changes across the estrous cycle in intact rats. Here, we describe an improved method for monitoring T(SKIN) in freely moving rats using a SubCue Mini datalogger mounted on the ventral surface of the tail. This method is noninvasive, cost-effective, and does not require restraints or tethering. We observed a distinct pattern of T(SKIN) across the estrous cycle characterized by low T(SKIN) on proestrous night. To determine whether this pattern was secondary to secretion of ovarian steroids, we monitored the thermoregulatory effects of 17β-estradiol (E(2)) and E(2) plus progesterone, administered via SILASTIC capsules to OVX rats. E(2) treatment of OVX rats significantly reduced T(SKIN) in the dark phase from 2 to 21 d after hormone treatment. The T(SKIN) of E(2)-treated OVX animals was not significantly different from OVX rats receiving E(2) plus progesterone. These data provide evidence that the reduction in T(SKIN) on proestrous night was secondary to elevated levels of ovarian estrogens. This study provides the first description of T(SKIN) changes with the estrous cycle and supports the role of estrogens in normal thermoregulation in the rat.
Collapse
Affiliation(s)
- Hemalini Williams
- Department of Pathology, Evelyn F. McKnight Brain Research Institute, University of Arizona College of Medicine, 1501 North Campbell Avenue, Tucson, Arizona 85724, USA
| | | | | |
Collapse
|
13
|
Roepke TA, Bosch MA, Rick EA, Lee B, Wagner EJ, Seidlova-Wuttke D, Wuttke W, Scanlan TS, Rønnekleiv OK, Kelly MJ. Contribution of a membrane estrogen receptor to the estrogenic regulation of body temperature and energy homeostasis. Endocrinology 2010; 151:4926-37. [PMID: 20685867 PMCID: PMC2946146 DOI: 10.1210/en.2010-0573] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The hypothalamus is a key region of the central nervous system involved in the control of homeostasis, including energy and core body temperature (Tc). 17β-Estradiol (E2) regulates Tc, in part, via actions in the basal hypothalamus and preoptic area. E2 primarily controls hypothalamic functions via the nuclear steroid receptors, estrogen receptor α/β. However, we have previously described an E2-responsive, Gq-coupled membrane receptor that reduces the postsynaptic inhibitory γ-aminobutyric acid-ergic tone and attenuates postovariectomy body weight gain in female guinea pigs through the administration of a selective Gq-mER ligand, STX. To determine the role of Gq-mER in regulating Tc, energy and bone homeostasis, ovariectomized female guinea pigs, implanted ip with temperature probes, were treated with STX or E2 for 7-8 wk. Tc was recorded for 4 wk, whereas food intake and body weight were monitored daily. Bone density and fat accumulation were determined postmortem. Both E2 and STX significantly reduced Tc in the females compared with controls. STX, similar to E2, reduced food intake and fat accumulation and increased tibial bone density. Therefore, a Gq-mER-coupled signaling pathway appears to be involved in maintaining homeostatic functions and may constitute a novel therapeutic target for treatment of hypoestrogenic symptoms.
Collapse
Affiliation(s)
- Troy A Roepke
- Department of Physiology and Pharmacology, Mail Code L334, Oregon Health and Science University, 3181 SW Sam Jackson Park Road, Portland, Oregon 97239, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
14
|
Huang H, Deng M, Jin H, Dirsch O, Dahmen U. Intraoperative vital and haemodynamic monitoring using an integrated multiple-channel monitor in rats. Lab Anim 2010; 44:254-63. [DOI: 10.1258/la.2009.009055] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The aim of this study is to give a hands-on description of the successful monitoring procedure established for extended liver resections and liver transplantations in rats and to provide the typical range of data as obtained before and after a hepatobiliary surgical procedure (right median hepatic vein [RMHV] ligation) in healthy male Lewis rats. All manipulations were performed in anaesthetized (3% isoflurane in O2 1 L/min) healthy male Lewis rats (250–350 g) with an integrated multiple-channel intraoperative monitor (Powerlab® system) using a series of sensors for data acquisition. Vital parameters (body temperature, electrocardiogram, respiratory rate and heart rate), haemodynamic parameters (mean arterial blood pressure [MAP] and central venous pressure) and liver perfusion parameters (inferior hepatic venous pressure, portal vein pressure [PVP], blood flow of portal vein and inferior hepatic cava) were monitored. Catheters were placed in microsurgical technique after careful exposure guided by anatomical landmarks. Vascular incisions were closed with interrupted sutures. Complete instrumentation of animals was performed within 1 h. No specific complications occurred. Vital and haemodynamic parameters such as MAP (94 ± 16.2 mmHg) or portal pressure (9.6 ± 1.34 mmHg) were in the same range as known for humans (MAP = 100 mmHg, portal pressure = 5–10 mmHg), whereas parameters dependent on the size of the body or organ such as flow rates (portal blood flow = 16.2 ± 6 mL/min) were obviously different compared with those of humans (portal blood flow = 800 mL/min). In conclusion, the normal range for vital, haemodynamic and liver perfusion parameters was reported as reference values to allow quality control for future surgical hepatobiliary research projects. As the procedure can be easily learned, the extensive intraoperative monitoring can be used routinely.
Collapse
Affiliation(s)
- Hai Huang
- Department of General, Visceral and Transplantation Surgery, University Hospital Essen, Essen, Germany
| | - Meihong Deng
- Department of General, Visceral and Transplantation Surgery, University Hospital Essen, Essen, Germany
| | - Hao Jin
- Department of General, Visceral and Transplantation Surgery, University Hospital Essen, Essen, Germany
| | - Olaf Dirsch
- Division of Pathology, German Heart Institute Berlin, Berlin, Germany
| | - Uta Dahmen
- Department of General, Visceral and Transplantation Surgery, University Hospital Essen, Essen, Germany
| |
Collapse
|