Diurnal changes of blood pressure, heart rate and body temperature during sleep in the rat

Context: Conditions such as osteoarthritis, obesity, and spinal cord injury limit the ability of patients to exercise, preventing them from experiencing many well-documented physiologic stressors. Recent evidence indicates that some of these stressors might derive from exercise-induced body temperature increases. Objective: To determine whether whole-body heat stress without exercise triggers cardiovascular, hormonal, and extra-cellular protein responses of exercise. Design: Randomized controlled trial. Setting: University research laboratory. Patients or Other Participants: Twenty-five young, healthy adults (13 men, 12 women; age = 22.1 ± 2.4 years, height = 175.2 ± 11.6 cm, mass = 69.4 ± 14.8 kg, body mass index = 22.6 ± 4.0) volunteered. Intervention(s): Participants sat in a heat stress chamber with heat (73°C) and without heat (26°C) stress for 30 minutes on separate days. We obtained blood samples from a subset of 13 participants (7 men, 6 women) before and after exposure to heat stress. Main Outcome Measure(s): Extracellular heat shock protein (HSP72) and catecholamine plasma concentration, heart rate, blood pressure, and heat perception. Results: After 30 minutes of heat stress, body temperature measured via rectal sensor increased by 0.8°C. Heart rate increased linearly to 131.4 ± 22.4 beats per minute (F6,24 = 186, P < .001) and systolic and diastolic blood pressure decreased by 16 mm Hg (F6,24 = 10.1, P < .001) and 5 mm Hg (F6,24 = 5.4, P < .001), respectively. Norepinephrine (F1,12 = 12.1, P = .004) and prolactin (F1,12 = 30.2, P < .001) increased in the plasma (58% and 285%, respectively) (P < .05). The HSP72 (F1,12 = 44.7, P < .001) level increased with heat stress by 48.7% ± 53.9%. No cardiovascular or blood variables showed changes during the control trials (quiet sitting in the heat chamber with no heat stress), resulting in differences between heat and control trials. Conclusions: We found that whole-body heat stress triggers some of the physiologic responses observed with exercise. Future studies are necessary to investigate whether carefully prescribed heat stress constitutes a method to augment or supplement exercise.

Download Full-text

Changes of arterial blood pressure and heart rate in the ox (Bos taurus) with changes of body temperature

The Journal of Physiology ◽

10.1113/jphysiol.1963.sp007219 ◽

1963 ◽

Vol 168 (4) ◽

pp. 736-746 ◽

Cited By ~ 12

Author(s):

D. L. Ingram ◽

G. C. Whittow

Keyword(s):

Blood Pressure ◽

Heart Rate ◽

Body Temperature ◽

Arterial Blood Pressure ◽

Bos Taurus ◽

Arterial Blood

Download Full-text

“On-” and “off-” cells in the rostral ventromedial medulla of rats held in thermoneutral conditions: are they involved in thermoregulation?

Journal of Neurophysiology ◽

10.1152/jn.00722.2013 ◽

2014 ◽

Vol 112 (9) ◽

pp. 2199-2217 ◽

Cited By ~ 7

Author(s):

Nabil El Bitar ◽

Bernard Pollin ◽

Daniel Le Bars

Keyword(s):

Blood Pressure ◽

Heart Rate ◽

Body Temperature ◽

Core Body Temperature ◽

Rostral Ventromedial Medulla ◽

Sequence Of Events ◽

Ventromedial Medulla ◽

Cyclic Variations ◽

On And Off Cells ◽

Core Body

In thermal neutral condition, rats display cyclic variations of the vasomotion of the tail and paws, synchronized with fluctuations of blood pressure, heart rate, and core body temperature. “On-” and “off-” cells located in the rostral ventromedial medulla, a cerebral structure implicated in somatic sympathetic drive, 1) exhibit similar spontaneous cyclic activities in antiphase and 2) are activated and inhibited by thermal nociceptive stimuli, respectively. We aimed at evaluating the implication of such neurons in autonomic regulation by establishing correlations between their firing and blood pressure, heart rate, and skin and core body temperature variations. When, during a cycle, a relative high core body temperature was reached, the on-cells were activated and within half a minute, the off-cells and blood pressure were depressed, followed by heart rate depression within a further minute; vasodilatation of the tail followed invariably within ∼3 min, often completed with vasodilatation of hind paws. The outcome was an increased heat loss that lessened the core body temperature. When the decrease of core body temperature achieved a few tenths of degrees, sympathetic activation switches off and converse variations occurred, providing cycles of three to seven periods/h. On- and off-cell activities were correlated with inhibition and activation of the sympathetic system, respectively. The temporal sequence of events was as follows: core body temperature → on-cell → off-cell ∼ blood pressure → heart rate → skin temperature → core body temperature. The function of on- and off-cells in nociception should be reexamined, taking into account their correlation with autonomic regulations.

Download Full-text

SKULL METASTASES OF FOLLICULAR CARCINOMA THYROID: A RARE CASE REPORT

10.36106/gjra/3605234 ◽

2021 ◽

pp. 24-25

Author(s):

Smriti Kumari ◽

Manoj Kumar Paswan ◽

Nishat Ahamad

Keyword(s):

Blood Pressure ◽

Heart Rate ◽

Case Report ◽

Body Temperature ◽

Thyroid Gland ◽

Basal Metabolic Rate ◽

Rare Case ◽

Follicular Carcinoma ◽

Rare Case Report ◽

Follicular Carcinoma Thyroid

The thyroid gland, usually located below and anterior to the larynx, consists of two bulky lateral lobes connected by a relatively thin isthmus. The thyroid is divided by thin brous septae into lobules composed of about 20 to 40 evenly dispersed follicles, lined by a cuboidal to low columnar [1] epithelium, and lled with PAS-positive thyroglobulin. The thyroid secretes hormones that control the heart rate, blood pressure, body temperature and basal metabolic rate

Download Full-text

Heat Stress, Physiological Response, and Heat-Related Symptoms among Thai Sugarcane Workers

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph17176363 ◽

2020 ◽

Vol 17 (17) ◽

pp. 6363

Author(s):

Pongsit Boonruksa ◽

Thatkhwan Maturachon ◽

Pornpimol Kongtip ◽

Susan Woskie

Keyword(s):

Blood Pressure ◽

Heart Rate ◽

Heat Stress ◽

Body Temperature ◽

Health Effects ◽

Heat Strain ◽

Control Measures ◽

Muscle Cramp ◽

Factory Workers ◽

Limit Values

Prolonged or intense exposure to heat can lead to a range of health effects. This study investigated heat exposure and heat-related symptoms which sugarcane workers (90 sugarcane cutters and 93 factory workers) experienced during a harvesting season in Thailand. During the hottest month of harvesting season, wet bulb globe temperature was collected in the work environment, and workloads observed, to assess heat stress. Urine samples for dehydration test, blood pressure, heart rate, and body temperature were measured pre- and post-shift to measure heat strain. Fluid intake and heat-related symptoms which subjects had experienced during the harvesting season were gathered via interviews at the end of the season. From the results, sugarcane cutters showed high risk for heat stress and strain, unlike factory workers who had low risk based on the American Conference of Governmental Industrial Hygiene (ACGIH) threshold limit values (TLVs) for heat stress. Dehydration was observed among sugarcane cutters and significant physiological changes including heart rate, body temperature, and systolic blood pressure occurred across the work shift. Significantly more sugarcane cutters reported experiencing heat-related symptoms including weakness/fatigue, heavy sweating, headache, rash, muscle cramp, dry mouth, dizziness, fever, dry/cracking skin, and swelling, compared to sugarcane factory workers. We conclude that the heat stress experienced by sugarcane cutters working in extremely hot environments, with high workloads, is associated with acute health effects. Preventive and control measures for heat stress are needed to reduce the risk of heat strain.

Download Full-text