Sanaz Aghajani, Elham Roshandel, Alireza Farsinezhad, Abbas Hajifathali,
Volume 42, Issue 1 (3-2018)
Abstract
Backgrond: Hematopoietic Stem Cells (HSCs), which have the ability to differentiate into various types of blood cell lines,
are usually separate from the bone marrow. But these cells are also present in a small amount in the peripheral blood,
and their amounts increase in blood following the injection of G-CSF. However, the mechanism involved in moving HSCs
under the influence of G-CSF is unknown. The aim of the present study was to investigate the role of circadian rhythms and
nervous system in HSCs mobilization. Despite the abandant information on the effect of 24-hour rhythms in physiological
processes in the body, there is no evidence of the role of circadian rhythms and its relation to the nervous system receiving
environmental information and neurotransmitters in HSCs mobilization.
Materials and methods: An experimental study was performed on 15 healthy bone marrow donors. Samples from
peripheral blood were taken at 9 o’clock in the morning and 9 o’clock at night before the injection of G-CSF as control
group, and at 9 o’clock in the morning and 9 o’clock at night on the fourth day of the G-CSF injection. The total counts of
leukocytes and CD34 + stem cells were performed on the samples using flow cytometry. Plasma levels of adrenaline and
noradrenaline were measured using ELISA method running Paired T test.
Results: In the present study, it was found that total cell count, stem cell count (CD34 +)(p value: 0.03), and plasma levels
of adrenaline (p value: 0.04) and noradrenaline (p value: 0.01) in the morning increased over night. Additionally, after
receiving the G-CSF, adrenalin and norepinephrine levels are higher in the early hours after the onset of lighting compared
with the night, and CD34 + cells count was higher in the morning compared with that in the evening similar to control
samples.
Discussion: Although numerous factors are involved in the etiology of azoospermia, clinical tests and genetic counseling
plays an important role in early detection of disease that helps to retrieve sperm production and fertility to the patient in
many cases.
Conclusion: Given that the number of stem cells and total WBC count in the morning were more than those at nights, in
general, following the injection of G-CSF, the number of stem cells circulating with the same pattern shows a multiplier
increase, it is suggested that the phenomenon of mobilization, like other biological processes of the body, is affected
by circadian rhythms. Therefore, increased secretion of adrenaline and noradrenaline in the morning and the effect on
ß2-adrenergic receptors in the bone marrow space resulted in increased mobilization and, during the day, reducing the
secretion of these neurotransmitters leads to the opposite process and reduces mobilization in the final hours of the day
and at night. In fact, G-CSF, along with other functional mechanisms for increasing the mobilization of stem cells to
the peripheral blood, uses this natural remedy for the body. These findings can be effective in enhancing approaches to
improving mobilization with the help of the nervous system.
Dr Asgar Iranpour, Ms Fereshteh Abdei, Ms Somayeh Azarian, Ms Sayeh Bolbol,
Volume 46, Issue 3 (9-2022)
Abstract
Background and Aim: It seems that performing exercise at different times of the day is associated with different responses in the functioning of the cardiac autonomic system. The aim of the present study was to investigate the acute effects of exhaustive exercise and circadian rhythms on recovery period heart rate variability in sedentary men with prehypertension.
Methods: A total of 15 sedentary men with prehypertension performed exhausting aerobic exercise in three sessions in the morning, noon, and afternoon using intra-subject comparisons and crossover design. Heart rate variability at baseline, end of exercise, and 5, 10, 20, and 30 minutes of recovery period were recorded at each time of exercise using a heart rate Holter-monitor. Preliminary data were analyzed using repeated measures analysis of variance and bonferroni post hoc test.
Results: Considering the participants' descriptive data (mean±SD age; 35.3±3.87, weight; 89.2±5.73, and mean blood pressure; 101.2±4.68), the results showed that performing exhausting exercise in the afternoon time compared to the morning and noon time caused a significant difference in standard deviation of RR interval (p=0/01 morning 10 min, p=0/01 noon 10 min), variance of RR interval (p=0/01 morning 5 min, p=0/001 noon 5 min; p=0/03 morning 10 min, p=0/001 noon 10 min) time indices and low-frequency(p=0/03 morning 5 min, p=0/01 noon 5 min; p=0/01 morning 10 min), and high-frequency(p=0/01 morning 5 min, p=0/01 noon 5 min; p=0/04 morning 10 min, p=0/01 noon 10 min) indices of heart rate variability in 5 and 10 min of recovery period.
Conclusion: It was found that performing exhaustive exercise by sedentary males with hypertension in the afternoon is desirable.
