To elucidate the effect of ethanol on the secretion of ACTH and beta-endorphin (BE) as the representatives of the pro-opiomelanocortin (POMC) system, as well as cortisol as the hypophyseally regulated peripheral hormone, we measured concentrations of serum ethanol and plasma ACTH, BE, and cortisol at 1- to 4-hr intervals for 12 hr after administration of 0.5 and 1.0 g ethanol/kg of body weight and placebo drinks between 1900-1945 hr to nine healthy volunteers according to a double-blind, cross-over design. Plasma ACTH, BE, and cortisol showed an expected diurnal rhythm with the highest levels at 0700 hr. Intake of ethanol had no statistically significant effects on plasma ACTH up to 0700 hr in the morning. The higher dose caused increased levels of BE at 0100 hr and both doses at 0200 hr. Plasma cortisol at 0400 hr was higher in subjects receiving 1.0 g ethanol/kg than in those receiving placebo (p
The effects of analgesia on plasma beta-endorphin (beta-E), serum cortisol and blood glucose responses were investigated in 20 distressed, mechanically ventilated neonates during the first 3 days of life. Morphine 0.1 mg/kg, meperidine 1 mg/kg or alfentanil 10 micrograms/kg were used for analgesia as clinically indicated. Plasma beta-E, serum cortisol and blood glucose were recorded before analgesia and 1 and/or 2, 12 and 24 h afterwards in the distress group and once in 20 healthy neonates (control group). beta-E, cortisol, and blood glucose before analgesia were significantly higher in the distress group than in the control group. Cortisol values had decreased significantly 2 h after analgesia and blood glucose within 12 h. Plasma beta-E values had decreased to the same level as in the controls 24 h after the start of analgesia. The results indicate that the stress response in the distressed neonates with cardiorespiratory problems, as assessed by beta-E, cortisol, and blood glucose, is attenuated by opioid medication, and it is concluded that these patients should be given adequate analgesia.
The aim of the study was to investigate the inter-relationships between pituitary-adrenal hormones and catecholamines during a prolonged competition over 6 days. Plasma adrenocorticotropic hormone (ACTH), cortisol (C), beta-endorphin (beta EP), free and sulphated adrenaline (A) and noradrenaline (NA) were measured in 11 volunteer male subjects during a national Nordic-ski race (323 km). Blood samples were obtained before the competition in the evening as control (D0), and before and after each day's racing (D1-D6). The mean daily heart rate (fc) was calculated from fc values recorded every minute during the race. The results showed the following: changes in mean fc [from 147 (SEM 3) to 156 (SEM 3) beats.min-1 according to the day] were not significant during the race. Diurnal variations in ACTH, beta EP and C were no longer apparent after the race: evening levels were higher than their respective D0 values during the race, except on D3 when there was a lack of response to exercise in the three hormones. Unlike ACTH and beta EP, pre- and postexercise C values on D1 and D2 were higher than those on the subsequent days (P less than 0.001). In contrast, there was a progressive accumulation of A and NA in pre- and postrace concentrations which reached a plateau in about 4 days. Positive correlations between exercise responses in ACTH, C and beta EP were found especially on D3 and D6 (P less than 0.001) but there were no significant correlations between catecholamines and the other three hormones. Thus, prolonged competition over 6 days evoked different control mechanisms for hormones of the pituitary-adrenal axis and catecholamines.(ABSTRACT TRUNCATED AT 250 WORDS)
BACKGROUND: Information processing and stress tolerance are necessary features for instrument flying (IFR), especially among student pilots. Psychological workload of IFR flight may lead to stress reactions such as neuroendocrine activity. METHODS: Neuroendocrine responses to an IFR flight with Vinka piston-engined primary trainer were studied in 35 male volunteers who participated in the basic military flying course of the Finnish Air Force (FAF). The student pilots performed a 40-min IFR flight mission and a control session on land in randomized order between 11.00 h and 15.00 h. The IFR flight included 3 NDB approaches and was evaluated by flight instructors. Blood samples were collected 15 min before, 5 min and 60 min after the flight as well as control session, and. Plasma ACTH, beta3-endorphin (BE), cortisol, prolactin, adrenaline (A) and noradrenaline (NA) were measured. Psychological evaluations included psychomotor test (Wiener), Multi Coordination and Attention Test, ability tests and personality tests (CMPS and 16 PF). The overall psychological evaluation was made by an aviation psychologist. RESULTS: Plasma ACTH was significantly higher before and 5 min after the flight compared with control levels, but plasma BE increased significantly only before the flight. Plasma cortisol was significantly elevated before and 5 min after the flight. Plasma prolactin, NA and A increases were significant 5 min after the flight. High A levels after the flight correlated significantly with poor IFR flight performance as well as with poor psychomotor test results. CONCLUSIONS: The plasma prolactin and NA increases after the flight represented a direct type of stress reaction to the flight situation. The plasma BE response to IFR flight was an anticipatory stress reaction, but plasma ACTH, cortisol and A responses included both anticipatory and direct types of stress reactions. Psychological factors, flight performance and neuroendocrine responses to IFR flight appear to be associated with each other. Therefore, neuroendocrine reactions as a response to the psychological workload of military flying could be used for identifying stress tolerance in military pilots.
The effects of psychological workload on the plasma levels of eight neuroendocrine hormones were studied in 5 undergraduate and 5 senior military pilots of the Finnish Air Force (FAF). All subjects performed the same short-term basic flight mission, which included the following: 1) start; 2) ILS-approach in minimum weather conditions; 3) visual approach; and 4) landing. The mission was performed twice: first with the BA Hawk MK 51 simulator with minimal G-forces and after that with a BA Hawk MK 51 jet trainer with Gz-forces below +2. Blood samples were collected 30 min before and 10 min after the mission and were measured for adrenaline, noradrenaline, ACTH, beta-endorphin, prolactin, vasopressin (AVP), atrial natriuretic peptide (ANP), and cortisol. The plasma levels of adrenaline, noradrenaline, ACTH, beta-endorphin, and cortisol did not change significantly in response to simulated or real flight. Plasma prolactin levels increased significantly (p = 0.037) in all subjects after the mission performed with jet trainer, and the increase was especially great in cadets. However, the same mission performed with the simulator did not raise plasma prolactin levels. This finding suggests that the psychological workload in a flight simulator does not correspond to the psychological workload in a real jet trainer, at least not in basic flying. Plasma AVP increased significantly (p = 0.032) after the mission performed with the simulator in cadets; this increase can be described as a "first-time effect." Plasma ANP also increased significantly (p
OBJECTIVE. To determine whether the use of opioids could reduce the hypoxemia and hemodynamic instability associated with routine intensive care procedures in neonates with respiratory distress. DESIGN. Randomized and placebo-controlled study. METHODS. Physiological, plasma beta-endorphin, cortisol, and glucose responses to routine treatment procedures were studied in 84 mechanically ventilated distressed neonates randomized into groups receiving 1 mg/kg meperidine or 0.9% saline 15 minutes before tracheal suction or routine nursing care. RESULTS. The duration of hypoxemia (transcutaneous partial pressure of O2
Physiological, plasma beta-endorphin and cortisol responses to nasotracheal intubation were studied in 20 distressed infants of median age 0.3 days (range 0.1-23 days) randomized into groups given pethidine 1 mg/kg (n = 10) or alfentanil 20 micrograms/kg plus suxamethonium 1.5 mg/kg (n = 10) before intubation. All of the infants were given glycopyrrolate 3-5 micrograms/kg. Hypoxaemia during intubation was found in all 10 infants in the pethidine group and in 7 of 10 infants in the alfentanil-suxamethonium group, its duration being significantly longer in the pethidine group and being associated with the duration of the intubation procedure. Blood pressure increased, but not statistically significantly, in all except 2 patients in the alfentanil-suxamethonium group and bradycardia appeared in 1 patient in each group. Plasma beta-endorphin and cortisol values did not show any statistically significant intra-group or inter-group differences. Newborn infants suffer from hypoxaemia during intubation when awake more and therefore need adequate premedication before elective intubation. One alternative is the combination of glycopyrrolate, alfentanil and suxamethonium described here, although the ideal medication and dosage still remain to be defined.
Plasma beta-endorphin, prolactin (PRL), FSH and LH were measured in 17 volunteer male subjects at rest and under the stress caused by a long-distance nordic ski race. The race induced increased levels of beta-endorphin and PRL in all skiers. The changes in PRL with exercise were significantly related to the changes in beta-endorphin (r = 0.69, p less than 0.001). Furthermore, the highly trained skiers training over 150 km.week-1 of nordic ski showed consistently higher post-exercise beta-endorphin and PRL levels than the moderately trained skiers who trained for 20 km.week-1. In addition the race induced slight falls in FSH and LH; however plasma gonadotropin levels did not show any correlation with plasma beta-endorphin concentrations and did not differ between the two groups of skiers. These results suggest that endogenous opioid peptides may modulate PRL secretion in heavy exercise, since they are of minor importance in the release of FSH and LH in such a situation. The observations also suggest that the degree of previous training and the exercise intensity do seem to be responsible for the hormonal changes.
In order to study the long-term effects of prolonged physical training in hypobaric hypoxia on plasma stress hormone concentrations, male rats (N = 84) were exposed to progressive running training on a motordriven treadmill for 10, 21 or 56 days, twice a day and 5 days a week either in hypobaric hypoxic (O2-pressure 740-770 mbar) or in normobaric conditions. The plasma samples were taken 14-16 hours after the last exercise bout. Plasma corticosterone concentration was higher in animals trained 10 days in hypobaric conditions than in those trained in normobaric conditions (1127 +/- 158 nmol/l and 710 +/- 87 nmol/l, p
A medico-legal case is presented where a jogger was struck by a car while crossing an intersection and later sought major damages in a civil court. This incident is reviewed in the context of overall information on injury to joggers by vehicles, and the possibility (raised by the defendant's counsel) that the euphoria generated by prolonged exercise may have created a sense of "invincibility" that predisposed the jogger to reckless actions. The defendants argued that the young man concerned was taking an amount of exercise that could have led to a jogging addiction and alteration of consciousness in a susceptible individual, and a history of alcohol, drug and video addiction was advanced as evidence that he may indeed have been a susceptible person. During the actual incident, the jogger recognised that the driver of the vehicle had not seen him, but nevertheless he proceeded to enter a crosswalk that had already been 75% traversed by the car, leaving himself only 0.6 metres of space, a half of the lane width normally required by a runner. A calculation of the relative velocities of the car and the jogger suggests that the latter must have veered 1-2 metres onto the main highway in order to pass in front of the care and be hit from the side. The behaviour of the jogger was plainly reckless, but more information is needed on the relative incidence of traffic injuries in joggers and walkers, on the prevalence of jogging addiction, and on diagnostic criteria for this condition before the accident could be categorically attributed to a jogging-related euphoria.