Increase In Scrotal Temperature Research Articles

Influence of heat stress on the quality of sperm production of boars-producers of different breeds and its fertilizing ability

The primary purpose of this work is to study the heat stress on the quality of sperm production in boars of different breeds (Large White, Landrace, Duroc, Maxgro). The authors found that heat stress affects the activity of pigs. The desire to reduce heat production leads to sedentary, passive animals, accompanied by decreased appetite, shortness of breath and inhibition of sexual reflexes in individuals. Against this background, the disturbances arising in the body, reinforced by a local increase in scrotal temperature, harm semen quality. The authors observed a tendency for decreased ejaculate volume and a decrease (statistically significant in most breeds) in the sperm concentration in the ejaculate by 11.47-34.96%. But at the same time, the organoleptic values (colour, consistency, smell) did not change. Heat stress hurts the fertility of pigs, reducing the probability of successful embryo implantation. The fertility of sow inseminated with semen from boars during heat stress decreased by 10.3-23.7%. And also, the fertility of the sow did not reach pre-stress levels until the end of the observation. Based on the study results, the authors found that, depending on the breed, pigs can tolerate heat stress in a more severe or milder form. The species Large White and Maxgro are less sensitive to increased ambient temperature (they had fewer changes in general condition, semen and fertility) than Duroc and Landrace pigs.

Twenty-four-hour monitoring of scrotal temperature in obese men and men with a varicocele as a mirror of spermatogenic function.

How do day and night scrotal temperatures, spermatogenesis parameters, sex hormones and intratesticular perfusion in obese men and men with a varicocele compare with healthy controls? Compared with healthy controls, 24-h monitoring of scrotal temperature in men with a varicocele and obese men showed higher temperatures and this condition was related to a significant alteration of spermatogenesis and stasis of testicular perfusion. Several studies have shown that increased scrotal temperature has dramatic effects on spermatogenesis. Scrotal hyperthermia by exposure to sauna is able to induce a significant alteration of sperm production. In a case-control study, data were collected over a period of 2 years from 60 subjects with risk factors for testicular heating and 20 healthy subjects who consecutively attended an andrology unit as participants in an infertility prevention program. Forty subjects with a left varicocele, 20 obese men and 20 healthy subjects who served as controls, were evaluated for testicular volumes, sex hormones, sperm parameters, sperm aneuploidies, mean transit time (MTT) of intratesticular blood and 24-h scrotal temperature monitoring by a cutaneous thermochip. Subjects with a varicocele were further subgrouped on the basis of normo or oligozoospermia (VN and VO). Student's t-test was used for statistical analysis. We found a significant increase in 24-h mean scrotal temperature in obese men and men with a varicocele compared with controls (both P < 0.01). This increase in scrotal temperature was associated with impaired sperm parameters and higher FSH plasma levels compared with controls. Dynamic evaluation of scrotal temperatures showed wide fluctuations in controls, but little variation in obese men and men with a varicocele. Men with VO had left and right increase in scrotal temperatures (the right was increased also versus VN, P < 0.01) (both P < 0.001). Men with VN showed a left scrotal temperature higher than controls (P < 0.01) and a right scrotal temperature no different from controls (34.92 ± 0.53 and 34.66 ± 0.65, respectively). Mean MTT values recorded in men with VO were significantly higher than men with VN and obese men (both P < 0.001). Different lifestyle, diet, occupation, stress level and environmental temperatures due to seasonal conditions are major limitations of this study. Our data suggested for the first time that dynamic evaluation of scrotal temperatures seems to reflect alterations of testicular function and perfusion in obese men and men with a varicocele. In these clinical conditions, spermatogenic impairment and scrotal heating seem to be related to different mechanisms. The dynamic evaluation of scrotal temperature in subjects with risk factors for testicular heating could allow the identification of subjects needing treatment or a change in lifestyle. No external funding was sought for this study, and the authors have no conflict of interest to declare.

Scrotal heat stress causes a transient alteration in tight junctions and induction of TGF-β expression

Specialized junctions, which occur at sites of Sertoli-Sertoli and Sertoli-germ cell contact of seminiferous epithelium, play pivotal roles in spermatogenesis. Slight increase in scrotal temperature can induce oligospermia or azoospermia via increasing germ cell apoptosis. In this study, we demonstrated that the expression of tight junction (TJ) components, such as occludin, claudin-3 and zonula occludens-1 (ZO-1), was reduced 24-48h after a single mild scrotal heat exposure (43°C for 30min), whereas mRNA levels of claudin-11 were increased. Moreover, the protein localization of occludin and ZO-1 was lost from the blood-testis barrier (BTB) site, whereas claudin-11 immunostaining became diffuse and cytoplasmic 2days following heat exposure. Electron microscopic analysis showed that 2days after the heat treatment, the intercellular space between the two adjacent Sertoli cells was expanded, coupled with defragmentation of actin bundles and the endoplasmic reticulum. In addition, the TJ permeability increased significantly 2days after the heat exposure and recovered approximately 10days later. Heat-induced reversible BTB disruption was associated with a transient induction of transforming growth factor (TGF)-β2, -3 and p38 mitogen-activated protein kinase activation. However, the TGF-β antagonist only partially prevented the heat-induced BTB disruption. In conclusion, the expression of TJ-associated molecules and BTB were reversibly perturbed after mild testicular hyperthermia, and the induction of TGF-β expression may be partially involved in heat-induced BTB damage.

Increase in Scrotal Temperature in Laptop Computer Users

No AccessJournal of UrologyUrological Survey: Male Infertility1 Aug 2005Increase in Scrotal Temperature in Laptop Computer Users Craig NiederbergerM.D. Craig NiederbergerCraig Niederberger More articles by this author View All Author Informationhttps://doi.org/10.1016/S0022-5347(01)68357-5AboutFull TextPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail "Increase in Scrotal Temperature in Laptop Computer Users." The Journal of Urology, 174(2), p. 661 © 2005 by American Urological Association, Inc.FiguresReferencesRelatedDetails Volume 174Issue 2August 2005Page: 661 Advertisement Copyright & Permissions© 2005 by American Urological Association, Inc.MetricsAuthor Information Craig Niederberger More articles by this author Expand All Advertisement PDF downloadLoading ...

Impact of a mild scrotal heat stress on DNA integrity in murine spermatozoa

An increase in scrotal temperature can lead to the production of poor quality spermatozoa and infertility. In the present study we have used mice to examine the impact of mild, scrotal heat stress (42 degrees C for 30 min) on numbers of spermatozoa as well as on the integrity of their DNA. Spermatozoa recovered from the epididymides hours (1 to 24) or days (7 to 32) after treatment were analysed using COMET and sperm chromatin structure (SCSA) assays. The treatment induced a stress response in both the testis and the epididymis that was associated with reduced expression of the cold inducible RNA binding protein (Cirp) and an increase in germ cell apoptosis (Apotag positive cells). Although spermatozoa present in the epididymis at the time of heating contained correctly packaged DNA, its integrity was compromised by heat stress. In addition, although some germ cells, which were present within the testis at the time of heat stress, were removed by apoptosis, many germ cells completed their development and were recovered as motile spermatozoa with damaged DNA. In conclusion, these data demonstrate that scrotal heat stress can compromise the DNA integrity of spermatozoa and this may have clinical implications for patients undergoing IVF and intra-cytoplasmic sperm injection (ICSI).

Increase in scrotal temperature in laptop computer users

Scrotal hyperthermia has been identified as a risk factor for male infertility. Laptop computers (LC) have become part of a contemporary lifestyle and have gained popularity among the younger population of reproductive age. LC are known to reach high internal operating temperatures. We evaluated the thermal effect of LC on the scrotum. Right and left scrotal temperature (ScT) was measured in 29 healthy volunteers in two separate 60 min sessions. ScT was recorded from thermocouples on a digital datalogger every 3 min with the working LC in a laptop position and in the same sitting position with approximated thighs without LC. ScT increased significantly on the right and left side in the group with working LC (2.8 degrees C and 2.6 degrees C, respectively; P<0001) and without LC (2.1 degrees C, P<0.0001). However, ScT elevation with working LC was significantly higher (P<0.0001). Working LC in a laptop position causes significant ScT elevation as a result of heat exposure and posture-related effects. Long-term exposure to LC-related repetitive transient scrotal hyperthermia is a modern lifestyle feature that may have a negative impact upon spermatogenesis, specifically in teenage boys and young men. Further studies of such thermal effects on male reproductive health are warranted.

Nurture vs nature: how can we optimize sperm quality?

Nurture vs nature: how can we optimize sperm quality?

Improvement of semen quality by nocturnal scrotal cooling and moderate behavioural change to reduce genital heat stress in men with oligoasthenoteratozoospermia

A questionnaire assessing factors that might cause an increase in scrotal temperature was completed by patients with reproducible oligoasthenoteratozoospermia of idiopathic nature or caused by varicocele. Evaluation by means of a grading scale revealed increased scrotal heat stress in oligoasthenoteratozoospermic patients compared with normozoospermic men (P < 0.01). In addition, long-term determination of 24 h scrotal temperature profiles showed that compared with semen donors, oligoasthenoteratozoospermic patients frequently had scrotal temperatures above 35.5 degrees C despite the same environmental temperatures (P < 0.05). In 88% of cases, maximum scrotal temperatures were measured during rest or sleep phases, whereas minimum values were recorded during physical activity or frequent change of position. Nocturnal scrotal cooling by means of an air stream resulted in a decrease in scrotal temperature of approximately 1 degrees C. Furthermore, a highly significant increase in sperm concentration (P < 0.0001) and total sperm output (P < 0.0001) was achieved after nocturnal scrotal cooling for 12 weeks together with a moderate decrease in factors leading to genital heat stress. A significant improvement in sperm motility (P < 0.05) and sperm morphology (P < 0.05) was also observed, but this improvement was markedly less pronounced than the changes in sperm concentration. This study shows the importance of genital heat stress as a cofactor in fertility impairment in men and indicates nocturnal scrotal cooling as a therapeutic option.

Improvement of semen quality by nocturnal scrotal cooling and moderate behavioural change to reduce genital heat stress in men with oligoasthenoteratozoospermia.

A questionnaire assessing factors that might cause an increase in scrotal temperature was completed by patients with reproducible oligoasthenoteratozoospermia of idiopathic nature or caused by varicocele. Evaluation by means of a grading scale revealed increased scrotal heat stress in oligoasthenoteratozoospermic patients compared with normozoospermic men (P < 0.01). In addition, long-term determination of 24 h scrotal temperature profiles showed that compared with semen donors, oligoasthenoteratozoospermic patients frequently had scrotal temperatures above 35.5 degrees C despite the same environmental temperatures (P < 0.05). In 88% of cases, maximum scrotal temperatures were measured during rest or sleep phases, whereas minimum values were recorded during physical activity or frequent change of position. Nocturnal scrotal cooling by means of an air stream resulted in a decrease in scrotal temperature of approximately 1 degrees C. Furthermore, a highly significant increase in sperm concentration (P < 0.0001) and total sperm output (P < 0.0001) was achieved after nocturnal scrotal cooling for 12 weeks together with a moderate decrease in factors leading to genital heat stress. A significant improvement in sperm motility (P < 0.05) and sperm morphology (P < 0.05) was also observed, but this improvement was markedly less pronounced than the changes in sperm concentration. This study shows the importance of genital heat stress as a cofactor in fertility impairment in men and indicates nocturnal scrotal cooling as a therapeutic option.

Increase in scrotal temperature in car drivers

Several recent studies have reported a gradual decline in sperm production in men. Endocrine disrupters as well as lifestyle have been suggested as risk factors. One lifestyle factor that may affect human fertility is driving a vehicle for a prolonged period. Several authors have suggested that driving position may increase the scrotal temperature. In order to validate this hypothesis we conducted continuous monitoring of scrotal temperature in real conditions, i.e. in men driving a car for a prolonged period. Nine volunteer men were asked to walk outside for 40 min and then to drive a car for 160 min. Scrotal temperatures were measured from thermocouples and values recorded every 2 min on a portable data recorder. Scrotal temperature increased significantly (P < 0.0001) in driving posture after 2 h of driving, reaching a value 1.7-2.2 degrees C higher than that recorded while walking. This link between driving position and increased scrotal temperature indicates a potential exposure of male reproductive function to lifestyle factors.

Effect of Increased Scrotal Temperature on Sperm Production in Normal Men

Abstract Objective: To determine whether application of polyester-lined athletic supports to bring the testes closer to the abdomen increases scrotal temperature and decreases sperm production. Design: Prospective clinical study. Setting: University academic medical center. Patient(s): Twenty-one healthy male volunteers. Intervention(s): The study consisted of a pretreatment period of 6 weeks, a treatment phase of 52 weeks, and a recovery phase until return to normal sperm production. During the treatment phase, the men wore polyester-lined athletic supports (single layer, double layer, or double layer impregnated with aluminum) throughout the day. Main Outcome Measure(s): Semen parameters and sperm function tests. Result(s): In all three groups of subjects, scrotal temperature was consistently increased by 0.8 to 1°C while the subjects were wearing the athletic supports. Mean sperm concentration; sperm motility, morphology, and viability; sperm hyperactivation; and ability of spermatozoa to penetrate zone-free hamster oocytes were not affected by the increase in scrotal temperature. Conclusion(s): The increase in scrotal temperature induced by polyester-lined athletic supports was insufficient to cause significant suppression of spermatogenesis or alteration of sperm function.

Effect of increased scrotal temperature on sperm production in normal men

Objective: To determine whether application of polyester-lined athletic supports to bring the testes closer to the abdomen increases scrotal temperature and decreases sperm production. Design: Prospective clinical study. Setting: University academic medical center. Patient(s): Twenty-one healthy male volunteers. Intervention(s): The study consisted of a pretreatment period of 6 weeks, a treatment phase of 52 weeks, and a recovery phase until return to normal sperm production. During the treatment phase, the men wore polyester-lined athletic supports (single layer, double layer, or double layer impregnated with aluminum) throughout the day. Main Outcome Measure(s): Semen parameters and sperm function tests. Result(s): In all three groups of subjects, scrotal temperature was consistently increased by 0.8 to 1°C while the subjects were wearing the athletic supports. Mean sperm concentration; sperm motility, morphology, and viability; sperm hyperactivation; and ability of spermatozoa to penetrate zone-free hamster oocytes were not affected by the increase in scrotal temperature. Conclusion(s): The increase in scrotal temperature induced by polyester-lined athletic supports was insufficient to cause significant suppression of spermatogenesis or alteration of sperm function.

Threshold temperatures of diencephalic neurons responding to scrotal warming

Neurons in the rat's thalamus and hypothalamus abruptly change their firing rates from minimum to maximum, or vice versa, with increase in scrotal temperature of 1 degree C or less ("switching response"). The threshold temperature of the switching response was compared in pairs of neurons simultaneously recorded from the right and left thalamus or from the right thalamus and the left hypothalamus. In dynamic conditions in which scrotal skin was gradually warmed at rates of 1-7 degrees C/min, the threshold temperatures of each neuron pair differed by only 0.4 degree C or less. The threshold temperatures of static responses of each pair of neurons, which was determined with step changes in scrotal temperature, fell in a range less than 0.8 degree C. Scrotal warming produced desynchronization of cortical EEG which was monitored during unit recordings. The change in EEG occurred at about the same scrotal temperature at which the switching responses of the diencephalic neurons were elicited.

Varying the temperature around the scrotum of a conscious dog between 15 degrees C and 31 degrees C does not affect respiration or metabolism.

A jockstrap which contained a temperature-controlled water perfusion system was placed around the scrotum of a resting conscious dog. Two series of experiments (five studies each) were carried out. In one series scrotal perfusion temperature was lowered in steps at 30-min intervals at temperatures of 31, 27, 23, 19, and 15 °C. Another comparable series of experiments was carried out except that the scrotal perfusion temperature was increased in the same steps from 15 to 31 °C. In both experiments there was a fall in hypothalamic and rectal temperatures with time but this was not different from control studies over a similar time in which scrotal perfusion temperature was maintained constant. Warming the scrotal area resulted in an increase in scrotal temperature and cooling the scrotal area resulted in a decrease in scrotal temperature. Despite these changes in local perfusion and scrotal temperatures, there were no significant changes in respiration or oxygen consumption. There was only a small increase in heart rate in the order of 12 beats/min with scrotal warming. It is unlikely that changes in thermal stimulation of the scrotum due to postural variations in resting conscious dogs are primarily responsible for variations in cardio–respiratory function for the conditions of this study.

The effect of temperature on characteristics of semen of rams

The effect on a number of semen characteristics of exposure to four periods (4, 6, 9, and 13.5 hr) of high temperature (41�C) was studied in nine rams. Individual rams varied in their susceptibility to seminal degeneration, and repeatability within rains at successive heat treatments was low. There were significant linear effects of duration of heat treatment on volume, density, number of spermatozoa per ejaculate, percentage of abnormal spermatozoa, motility, fructose concentration, and reaction time. There was a significant effect of week of collection after treatment on all characteristics. The major component of this effect was quadratic, showing a degeneration and recovery pattern. Evidence of degeneration appeared at approximately the 12th day and reached its maximum at the 19th day, after which recovery was shown up to the 30th day. This pattern was observed in most of the characteristics studied. There was a significant negative correlation (r = -0.593 ; P &lt; 0.01) between a mean semen composite score and the maximum subcutaneous scrotal temperature recorded during the corresponding heat treatment period. Correlations between mean semen composite score and the increase in scrotal temperature (r = -0.22) and the minimum difference between body and scrotal temperature (r = +0.33) were not significant. Thus, the maximum subcutaneous scrotal temperature appears the important factor involved in seminal degeneration following exposure to high temperature.