Unacylated ghrelin, leptin, and appetite display diurnal rhythmicity in lean adults.

2021 ◽  
Author(s):  
Iain Templeman ◽  
Harry A. Smith ◽  
Jean-Philippe Walhin ◽  
Benita Middleton ◽  
Javier T. Gonzalez ◽  
...  
Keyword(s):  
Diurnal Rhythm ◽  
Diurnal Rhythms ◽  
Appetite Regulation ◽  
Ghrelin Concentration ◽  
Unacylated Ghrelin ◽  
Liquid Meal ◽  
Healthy Humans ◽  
Plasma Leptin ◽  
Light Sleep ◽  
Meal Replacements

Constant routine and forced desynchrony protocols typically remove the effects of behavioural/environmental cues to examine endogenous circadian rhythms, yet this may not reflect rhythms of appetite regulation in the real world. It is therefore important to understand these rhythms within the same subjects under controlled diurnal conditions of light, sleep and feeding. Ten healthy adults (9M/1F, Mean ±SD: age: 30 ± 10 y; BMI: 24.1 ± 2.7 kg·m-2) rested supine in the laboratory for 37 hours. All data were collected during the final 24 hours of this period (i.e. 0800 - 0800 h). Participants were fed hourly isocaloric liquid meal replacements alongside appetite assessments during waking before a sleep opportunity from 2200-0700 h. Hourly blood samples were collected throughout the 24-h period. A diurnal rhythm in mean plasma unacylated ghrelin concentration was identified (p=0.04), with the acrophase occurring shortly after waking (08:19 h), falling to a nadir in the evening with a relative amplitude of 9%. Plasma leptin concentration also exhibited a diurnal rhythm (p<0.01), with the acrophase occurring shortly after lights-out (00:32 h) and the lowest concentrations at midday. The amplitude for this rhythm was 25%. Diurnal rhythms were established in all dimensions of appetite except for sweet preference (p=0.29), with both hunger (21:03) and prospective food consumption (19:55) reaching their peak in the evening before falling to their nadir shortly after waking. Under controlled diurnal conditions, simultaneous measurement of leptin, unacylated ghrelin, and subjective appetite over a 24-hour period revealed rhythmicity in appetite regulation in lean, healthy humans.

Effects of light and food on plasma leptin concentrations in ewes

2000 ◽  
Vol 71 (2) ◽  
pp. 235-242 ◽  
Author(s):  
T. Tokuda ◽  
T. Matsui ◽  
H. Yano
Keyword(s):  
Diurnal Rhythm ◽  
Energy Requirement ◽  
Pulse Length ◽  
Pulse Amplitude ◽  
Pulse Frequency ◽  
Pulse Plasma ◽  
Dark Cycle ◽  
Blood Samples ◽  
The Mean ◽  
Plasma Leptin

AbstractPlasma leptin concentration shows pulsatility and diurnal rhythm in humans. However, there are few reports concerning the 24-h profile of circulating leptin levels in ruminants. Five crossbred ewes were housed in metabolism cages under a 1-h light-dark cycle. The ewes were offered alfalfa hay daily to meet their energy requirement. Blood samples were collected at 15-min intervals for 24 h. Plasma leptin concentrations were determined using a radioimmunoassay and the profile of plasma leptin levels was analysed by the PULSAR algorithmic program for detecting pulse. Plasma leptin concentration changed in a pulsatile fashion. The mean leptin concentration was 2·93 ng/ml. The mean pulse frequency was 4·8 pulses per day and the mean pulse amplitude was 0·67 ng/ml with an average pulse length of 1:13 h. Plasma leptin level was not affected by feeding or lighting cycle. These results indicate that plasma leptin level in sheep shows pulsatility but diurnal rhythm is not exhibited.

Studies in Diurnal Rhythms

1951 ◽  
Vol 28 (2) ◽  
pp. 165-172
Author(s):  
J. L. CLOUDSLEY-THOMPSON
Keyword(s):  
Diurnal Rhythm ◽  
Rhythmic Activity ◽  
Temperature Fluctuations ◽  
West African ◽  
Diurnal Rhythms ◽  
Locomotory Activity ◽  
Depressing Effect ◽  
African Species ◽  
Fluctuating Light ◽  
Effect Of Light

Visual experiments on two small British species of millipedes have demonstrated that the diurnal cycle of rhythmic activity as represented by the number of animals on the surface is primarily a response to light and darkness, but is also correlated with the stimulus of falling temperature in the evening. Aktograph experiments on two large West African species of millipedes have demonstrated an endogenous diurnal rhythm independent of fluctuating light and temperature, and persisting (in Ophistreptus) up to 19 days. Locomotory activity is stimulated both by increases and decreases of temperature; and it is probable that temperature fluctuations are of primary importance in the initiation of diurnal rhythms. The effect of light on activity is slight, but constant temperatures over long periods have, a depressing effect.

The effect of interval versus continuous exercise on plasma leptin and ghrelin concentration in young trotters

2011 ◽  
Vol 14 (3) ◽  
pp. 373-378 ◽  
Author(s):  
S. Kowalik ◽  
W. Kędzierski
Keyword(s):  
Lactic Acid Concentration ◽  
Experimental Conditions ◽  
Ghrelin Concentration ◽  
Interval Exercise ◽  
Continuous Exercise ◽  
Type Of Exercise ◽  
Exercise Induced ◽  
Interval Type ◽  
Plasma Leptin ◽  
Plasma Ghrelin Concentration

The effect of interval versus continuous exercise on plasma leptin and ghrelin concentration in young trottersThe effect of interval vs. continuous exercise on plasma leptin and ghrelin concentration in young Standardbred horses was studied. The experiment was conducted on 27 trotters, in the age between 2 and 3 years. They were divided into two groups according to the type of exercise. Blood samples were collected through jugular venipuncture in the following experimental conditions: at rest, immediately after exercise and 30 minutes after the end of the effort. Plasma leptin and ghrelin concentrations were determined using RIA tests. The continuous exercise induced an increase in plasma leptin concentration whereas the interval type of exercise did not influence the level of this hormone (3.47 ± 0.78 vs. 4.07 ± 0.94 and 2.31 ± 0.15 vs. 2.36 ± 0.21 ng/mL, respectively). The plasma ghrelin concentration measured after the continuous exercise, significantly increased (720 ± 27.4 vs. 814 ± 13.8; p ≤ 0.05) whereas concentration of this hormone assessed after the interval exercise, significantly dropped (982 ± 56.5 vs. 842 ± 35.6 pg/mL; p ≤ 0.05). The changes in plasma ghrelin concentration measured after the end of the effort correlated inversely with blood lactic acid concentration. In conclusion, the obtained results showed that medium-intensive type of exercise, such as trot, interval or continuous, slightly affected plasma leptin level but significantly affected plasma ghrelin concentration in young Standardbred trotters.

Circadian Rhythms of Serum Thyrotrophin and Body Temperature in Euthyroid Individuals and their Responses to Warming

1984 ◽  
Vol 67 (4) ◽  
pp. 433-437 ◽  
Author(s):  
B. P. O'malley ◽  
A. Richardson ◽  
N. Cook ◽  
S. Swart ◽  
F. D. Rosenthal
Keyword(s):  
Body Temperature ◽  
Circadian Rhythms ◽  
Diurnal Rhythm ◽  
Normal Subjects ◽  
The Body ◽  
Diurnal Rhythms ◽  
Tsh Levels

1. The diurnal rhythms of body temperature and serum thyrotrophin (TSH) levels in euthyroid individuals behaved inversely to one another. 2. An artificially induced rise in the body temperature of these individuals was accompanied by a fall in serum thyrotrophin levels, the amplitudes of their respective rhythms decreasing simultaneously. 3. There was a marked correlation between the degrees of change in body temperature and circulating thyrotrophin levels respectively during warming. 4. In normal subjects manipulation of the diurnal rhythm of body temperature brings about inverse alterations in the thyrotrophin rhythm.

Glucagon-like peptide 1 inhibition of gastric emptying outweighs its insulinotropic effects in healthy humans

1997 ◽  
Vol 273 (5) ◽  
pp. E981-E988 ◽  
Author(s):  
Michael A. Nauck ◽  
Ulrich Niedereichholz ◽  
Rainer Ettler ◽  
Jens Juul Holst ◽  
Cathrine Ørskov ◽  
...  
Keyword(s):  
Gastric Emptying ◽  
Normal Subjects ◽  
Diabetic Patients ◽  
Phenol Red ◽  
Type 2 Diabetic Patients ◽  
Liquid Meal ◽  
Healthy Humans ◽  
Glucagon Like Peptide ◽  
Glucagon Like Peptide 1 ◽  
Insulin Responses

Glucagon-like peptide 1 (GLP-1) has been shown to inhibit gastric emptying of liquid meals in type 2 diabetic patients. It was the aim of the present study to compare the action of physiological and pharmacological doses of intravenous GLP-1-(7—36) amide and GLP-1-(7—37) on gastric emptying in normal volunteers. Nine healthy subjects participated (26 ± 3 yr; body mass index 22.9 ± 1.6 kg/m2; hemoglobin A1C 5.0 ± 0.2%) in five experiments on separate occasions after an overnight fast. A nasogastric tube was positioned for the determination of gastric volume by use of a dye-dilution technique (phenol red). GLP-1-(7—36) amide (0.4, 0.8, or 1.2 pmol ⋅ kg−1 ⋅ min−1), GLP-1-(7—37) (1.2 pmol ⋅ kg−1 ⋅ min−1), or placebo was infused intravenously from −30 to 240 min. A liquid meal (50 g sucrose, 8% amino acids, 440 ml, 327 kcal) was administered at 0 min. Glucose, insulin, and C-peptide were measured over 240 min. Gastric emptying was dose dependently slowed by GLP-1-(7—36) amide ( P < 0.0001). Effects of GLP-1-(7—37) at 1.2 pmol ⋅ kg−1 ⋅ min−1were virtually identical. GLP-1 dose dependently stimulated fasting insulin secretion (−30 to 0 min) and slightly reduced glucose concentrations. After the meal (0–240 min), integrated incremental glucose ( P < 0.0001) and insulin responses ( P = 0.01) were reduced (dose dependently) rather than enhanced. In conclusion, 1) GLP-1-(7—36) amide or -(7—37) inhibits gastric emptying also in normal subjects, 2) physiological doses (0.4 pmol ⋅ kg−1 ⋅ min−1) still have a significant effect, 3) despite the known insulinotropic actions of GLP-1-(7—36) amide and -(7—37), the net effect of administering GLP-1 with a meal is no change or a reduction in meal-related insulin responses. These findings suggest a primarily inhibitory function for GLP-1 (ileal brake mechanisms).

scholarly journals Effect of Glutamate on Postprandial Glucose Excursion and Gastric Emptying of a Lipid-Containing Liquid Meal in Healthy Humans

2011 ◽  
Vol 140 (5) ◽  
pp. S-868
Author(s):  
Hiroko Hosaka ◽  
Motoyasu Kusano ◽  
Hiroaki Zai ◽  
Shiko Kuribayashi ◽  
Atsuto Nagoshi ◽  
...  
Keyword(s):  
Gastric Emptying ◽  
Postprandial Glucose ◽  
Glucose Excursion ◽  
Liquid Meal ◽  
Healthy Humans ◽  
Postprandial Glucose Excursion

scholarly journals Diurnal rhythms of cortisol and melatonin in night eating and non-night eating male police officers

2019 ◽  
Vol 29 (Supplement_4) ◽  
Author(s):  
J K Sørensen ◽  
M A Jensen ◽  
ÅM Hansen ◽  
R Rugulies ◽  
A H Garde
Keyword(s):  
Diurnal Rhythm ◽  
Police Officers ◽  
Night Shift ◽  
Eating Behaviour ◽  
Cortisol Concentration ◽  
Diurnal Rhythms ◽  
Consecutive Night ◽  
Night Eating ◽  
Main Meal ◽  
Night Shifts

Abstract Background Working during the night has in previous studies been associated with behavioural changes and diseases. Disturbance between behavioural and biological circadian rhythms have been suggested as a possible mechanism linking night work with cardiovascular diseases and pre-diabetic changes. The aim of this study was to investigate if night eating during two, four and seven consecutive night shifts is associated with differences in the diurnal rhythms of cortisol and melatonin in male police officers in Denmark. Methods We conducted an experimental study among 37 male police officers in Denmark who all collected data on the last night shift in three different work schedules with two, four and seven consecutive night shifts, respectively. Night eating was self-reported and defined as eating at least one main meal between midnight and early morning. Differences in the diurnal rhythms of concentrations of cortisol and melatonin in saliva were tested by phase changes and amplitude differences. Results Sixteen (43.2%) police officers ate a main meal during the last night shift in all three work schedules. The timing of the lowest cortisol concentration was on average delayed with 2:10 hours (95% CI 0:24-3:56 hours) and the level of the lowest cortisol concentration was on average supressed with 66% (95% CI 47-94%) for night eaters compared to non-night eaters. There was no association with number of consecutive night shifts. The phase and amplitude of melatonin were not statistically significantly different between night eaters and non-night eaters. Conclusions Night eating behaviour is associated with differences in the diurnal rhythm of cortisol in Danish male police officers working during the night. The difference in cortisol rhythm between night eaters and non-night eaters on night shifts is not affected by the number of consecutive night shifts. Key messages Night eating behaviour is associated with differences in the diurnal rhythm of cortisol. Future studies should focus on potential health outcomes of night eating behaviour among night workers.

scholarly journals Human Milk Endocannabinoid Levels as a Function of Obesity and Diurnal Rhythm

Nutrients ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 2297
Author(s):  
Palika Datta ◽  
Michael W. Melkus ◽  
Kathleen Rewers-Felkins ◽  
Dhavalkumar Patel ◽  
Tiffany Bateman ◽  
...  
Keyword(s):  
Breast Milk ◽  
Human Milk ◽  
Cognitive Processes ◽  
Diurnal Rhythm ◽  
Limit Of Detection ◽  
Endocannabinoid System ◽  
Storage Conditions ◽  
Diurnal Rhythms ◽  
Night Time ◽  
And Storage

The endocannabinoid system is involved in the regulation of a variety of physiological and cognitive processes. While the endocannabinoids 2-arachidonoylglycerol (2-AG) and anandamide (N-arachidonoylethanolamine, AEA) have been found in breast milk, their role(s) have yet to be determined. This study determined the normal concentration ranges of endocannabinoids (2-AG and AEA) in breast milk and the influences, if any, of obesity and diurnal rhythms on their levels. Milk samples were collected from 36 breastfeeding mothers at 4–8 weeks postpartum at each feed over a 24-h period, and further stratified into three groups based on body mass index (BMI). The samples were analyzed using liquid chromatography mass spectrometry. AEA was below the limit of detection and 2-AG levels averaged 59.3 ± 18.3 ng/mL (± SD) in women with normal BMI. Wide-ranging 2-AG concentrations in the overweight (65.5 ± 41.9 ng/mL) /obese (66.1 ± 40.6 ng/mL) groups suggest BMI may be a contributing factor influencing its levels. Following a diurnal pattern, there was a significantly higher 2-AG concentration observed during the day, as compared to night time samples. In conclusion, our study clearly suggests that appropriate milk collection and storage conditions are critical. Further, body weight and diurnal rhythm appear to influence levels of 2-AG. Based on these results, future studies are underway to determine what specific roles endocannabinoids may play in human milk and how elevated levels of 2-AG may modulate infant appetite and health.

Diurnal rhythm of cone opsin expression in the teleost fish Haplochromis burtoni

2005 ◽  
Vol 22 (2) ◽  
pp. 135-141 ◽  
Author(s):  
SVEN HALSTENBERG ◽  
KRISTIN M. LINDGREN ◽  
SANJUM P. S. SAMAGH ◽  
MIREYA NADAL-VICENS ◽  
STEVE BALT, ◽  
...  
Keyword(s):  
Diurnal Rhythm ◽  
Teleost Fish ◽  
Outer Segment ◽  
Expression Patterns ◽  
Diurnal Rhythms ◽  
Opsin Expression ◽  
Cone Opsin ◽  
Haplochromis Burtoni ◽  
Polymerase Chain ◽  
Cone Opsins

The biochemical and morphological specializations of rod and cone photoreceptors reflect their roles in sight. The apoprotein opsin, which converts photons into chemical signals, functions at one end of these highly polarized cells, in the outer segment. Previous work has shown that the mRNA of rod opsin, the opsin specific to rods, is renewed in the outer segment with a diurnal rhythm in the retina of the teleost fish Haplochromis burtoni. Here we show that in the same species, all three cone opsin mRNAs (blue, green, and red) also have a diurnal rhythm of expression. Quantitative real-time polymerase chain reaction (PCR) with primer pairs specific for the cone photoreceptor opsin subtypes was used to detect opsin mRNA abundance in animals sacrificed at 3-h intervals around the clock. All three cone opsins were expressed with diurnal rhythms similar to each other but out of phase with the rod opsin rhythm. Specifically, cone opsin expression occurs at a higher level near the onset of the dark period, when cones are not used for vision. Finally, we found that the rhythm of cone opsin expression in fish appears to be light dependent, as prolonged darkness changes normal diurnal expression patterns.

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