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Biomedical subjects

P K Opstad

Publications and source records attributed to P K Opstad.

At least 19 recordsLinked to original sources

Response of circulating immune cells to major gunshot injury, haemorrhage, and acute surgery.

PURPOSE: The purpose of this study was to use an established porcine model to investigate the effects on immune function of severe gunshot injury. METHODS: Twelve pigs sustained two standardised rounds, one through right femur and one through left upper abdomen. First aid treatment and acute surgery was started immediately. Blood samples were drawn before shooting and after 75 min. Circulating neutrophils were isolated and reactive oxygen species (ROS) measured. Serum levels of tumour necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), IL-6, and IL-10 were determined at 0, 75 min, as well as 2h after incubation with 1 microg/ml endotoxin in an ex vivo whole blood model. RESULTS: TNF-alpha, IL-1beta, and IL-6 significantly increased at 75 min. ROS in circulating granulocytes tended to increase (NS). Incubation with endotoxin led to a more than 100-fold increase of TNF-alpha pre-trauma, compared to a three-fold increase post-trauma (p<0.0001 between groups). A similar pattern was obtained for IL-1beta, and IL-6. IL-10 was below detection in all samples. The granulocytes maintained their ability to react to the protein kinase C activator phorbol myristate acetate (PMA) after trauma. CONCLUSION: Severe gunshot injury and peritraumatic stress rapidly activate circulating immune cells, but reduce their capacity to react to a subsequent challenge to endotoxin.

Abdominal Injuries↗

Glycine--an important neurotransmitter and cytoprotective agent.

BACKGROUND: Glycine, the simplest of the amino acids, is an essential component of important biological molecules, a key substance in many metabolic reactions, the major inhibitory neurotransmitter in the spinal cord and brain stem, and an anti-inflammatory, cytoprotective, and immune modulating substance. MATERIAL AND METHODS: Based on available literature, we discuss some of the important biological properties of glycine. In addition, we describe some clinical disorders where glycine plays a central role, either as an essential structural element, or through its metabolism or receptors. RESULTS: The past few years have witnessed a broadening of glycine research. The traditional prime interest in aspects related to its role as an inhibitory neurotransmitter in the central nervous system has been expanded to equally emphasize other organs and tissues. With the demonstration of glycine-gated chloride channels on neurons in the central nervous system, on most leukocytes, and subsequently on other cells as well, a unifying mechanism of action accounting for many of the widespread effects of glycine has been found. CONCLUSIONS: Glycine is a simple, easily available, and inexpensive substance with few and innocuous side-effects. The diversity of biological activities is well documented in the literature. Despite this, glycine has only gained a modest place in clinical medicine.

Cytoprotection↗

Modest protection of early hydrocortisone treatment in a rat model of volume-controlled haemorrhage.

BACKGROUND: Major insults may trigger generalized inflammatory responses that contribute to progressive multiple organ dysfunction. The present study was performed to test the potential of early hydrocortisone treatment to influence these responses as well as organ function following an episode of rapid and profound blood loss. METHODS: In isoflurane anaesthesia, 35 spontaneously breathing male Sprague-Dawley rats were bled 2.5 ml 100 g-1 body weight over 10 min. Immediately following withdrawal of blood, one group (n = 17) was given 2 mg of hydrocortisone, and the other (n = 18) had the same amount of normal saline. Seventy-five minutes after initiation of bleeding, two-thirds of the blood was retransfused, together with a new injection of hydrocortisone or saline. Thereafter the rats were observed for 2 h. Key mediators of systemic inflammation and plasma markers of organ function and integrity were measured. Internal organs were weighed and scored for visible pathology. Leukocyte infiltration of the liver was counted in a light microscope. RESULTS: Hydrocortisone reduced the plasma levels of IL-6 (P < 0.05); non-significant reductions of TNF-alpha (P = 0.12) and IL-10 (P = 0.44) were noted. The synthesis of reactive oxygen species in peritoneal cells was unaffected. Relative organ weights and organ injury scores tended to be reduced, but only wet organ weight for the lungs reached statistical significance. Leukocyte infiltration of the liver was equal in both groups. Plasma levels of ALT, AST, alpha-GST and creatinine did not differ significantly between groups. Two of the hydrocortisone treated rats died compared with four controls. CONCLUSION: Early treatment with hydrocortisone had a limited organ protective effect in this model of controlled haemorrhagic shock. Although a general tendency for better outcome in the hydrocortisone group was noted, clear-cut and significant advantages of the treatment were not obtained.

Animals↗

Chemiluminescence response of granulocytes from elite athletes during recovery from one or two intense bouts of exercise.

In this study nine elite athletes each participated in three different 24- h trials, as follows: (1) complete bed rest (REST), (2) one bout of exercise at 1515 hours (ONE-EX), (3) two exercise bouts, one at 1100 hours and one at 1515 hours (TWO-EX-3 h), and (4) two exercise bouts, one at 0800 hours and one at 1515 hours (TWO-EX-6 h). Exercise was performed on a cycle ergometer with 10 min of warm-up and then 65 min at an exercise intensity of 75% of maximum oxygen uptake (VO(2max)). The polymorphonuclear neutrophil (PMN) counts increased consistently in response to exercise, and more in trial TWO-EX-3 h than in the two other exercise trials (P < 0.01). The respiratory burst of PMN was measured as chemiluminescence (CL), obtained with phorbol myristate (PMA) and serum-opsonised zymosan (SOZ) as stimulators. Exercise triggered the CL response for a defined number of PMN, significantly above baseline (REST) values (P < 0.05) for ONE-EX and TWO-EX-3 h, but not for TWO-EX-6 h. The strongest response was observed for TWO-EX-3 h, but the difference between exercise procedures was not significant. However, as a novel approach, a comparison was made using total oxidative potentials per litre of blood, as obtained by combining CL values and PMN numbers. TWO-EX-3 h yielded significantly higher values than the other experimental treatments. Thus, by this measure the total oxidative potential of PMN x l(-1) blood remains at a higher level with short intervals between exercise bouts (i.e. 3 h instead of 6 h), possibly due to a combined effect of cell number increase and the priming state of PMN. This may suggest that for intensive training twice a day, a recovery phase of 5-6 h is preferable. The elevation in cell number is best explained by a combined effect of catecholamines and cortisol. Growth hormone is one probable candidate as a stimulator of CL, but other molecular participants that respond to exercise may exert roles as either stimulators or inhibitors of CL.

Adenosine Deaminase↗

Moderate hypothermia blunts the inflammatory response and reduces organ injury after acute haemorrhage.

BACKGROUND: Reduced body temperature is a common companion to trauma/haemorrhage. Several clinical studies have identified hypothermia as an independent risk variable predisposing to increased morbidity and mortality. At the same time it is known that most enzymatic reactions are downregulated at temperatures below 37 degrees C. Theoretically this should restrain the inflammatory response and protect the host from remote organ injury. The study was performed to test this hypothesis. METHODS: Twenty-six male Sprague Dawley rats were used for the experiments. Volume controlled haemorrhagic shock was induced by withdrawal of 2.5 ml blood/100 g body weight over 10 min. Half of the animals (n=13) were then cooled to 32.5-33 degrees C, the other half (n=13) were kept normothermic (37.5+/-0.5 degrees C). Seventy-five minutes after initiation of bleeding, two-thirds of the blood was retransfused. Thereafter the rats were observed for 2 h. Key substances of systemic inflammation were determined (plasma values of TNF-alpha, IL-6, IL-10, and corticosterone; reactive oxygen species in peritoneal phagocytes), plasma markers of organ function and integrity (AST, ALT, alphaGST, creatinine, urea), and survival. RESULTS: Hypothermia reduced the release of IL-6 (P<0.01). The reductions of plasma levels of TNFalpha (P=0.07) and IL-10 (P=0.09) were less clear-cut. The release of reactive oxygen species diminished (P<0.01). Organ injury was ameliorated, as reflected by decreased levels of AST (P<0.01), alphaGST (P<0.01), and creatinine (P<0.01). Both groups experienced an almost identical increase of plasma corticosterone. None of the hypothermic rats died, compared to two normothermic. CONCLUSION: Moderate hypothermia had an organ protective effect in this model of controlled haemorrhagic shock. This coincided with a significant reduction of the proximal cytokine IL-6 and reactive oxygen species, which conceivably influenced the outcome.

Animals↗

Hypothalamic-pituitary-adrenal axis activation by experimental periodontal disease in rats.

Organisms respond to inflammatory conditions by mounting a co-ordinated complex series of adaptive responses involving the immune, nervous and endocrine systems that are aimed at restoring the homeostatic balance. We have recently shown in a rat model that inappropriate hypothalamic-pituitary-adrenal (HPA) axis regulation and a subsequent inability to mount a suitable glucocorticoid response to gingival inflammation may influence susceptibility to periodontal disease. This study was designed to investigate whether ligature- and bacterial lipopolysaccharide (LPS)-induced inflammation in the gingival connective tissues may activate this physiological axis, and to further explore the significance of HPA regulation in periodontal disease. Experimental periodontal disease was induced in major histocompatibility complex (MHC)-identical but HPA low (LEW) and high (F344) responding rat strains. We tested (1) whether ongoing periodontal disease activates the HPA axis as measured by corticosterone levels, and (2) whether genetic differences in HPA regulation modulate periodontal disease progression. In the F344 strain. the periodontal tissue destruction was more severe. This observation was associated with a significant increase of corticosterone levels in F344 rats only. Addition of LPS at the gingival inflammatory site led to a further increase of corticosterone levels and disease severity in F344 rats. These findings illustrate a positive feedback loop between the HPA axis and periodontal disease: the disease activates the HPA axis, and a genetically determined high HPA responsivity further increases disease susceptibility.

Alveolar Bone Loss↗

No effect of seasonal variation in training load on immuno-endocrine responses to acute exhaustive exercise.

This study was designed to examine the relationship between seasonal changes in training and competition load, and changes in leukocyte subsets, stress hormones, and interleukin-6 (IL-6) in response to a standardised bout of endurance exercise. In addition, changes in mood states were monitored. Ten male, international Nordic skiers, age 20-29, maximal oxygen uptake 70-82 ml x kg(-1) x min(-1) performed the same incremental treadmill tests to exhaustion at the same time of day (+/-1 h), during the competitive season (in-season HI test) and the recovery season (off-season LO test). The subject filled out a training and competition log (TC score) for three weeks prior to each test and a 65-item Profile of Mood State (POMS) test on arrival at the laboratory. Venous blood for haematological, hormonal, and IL-6 analysis was drawn before and at 0, 15, 30, 60, 120 and 240 min after the test. TC score was more than twice as high during the competitive season (16.0 +/- 3.9) compared to the off-season period (7.0 +/- 4.4). An ANOVA procedure for repeated measures showed no difference in exercise induced changes in concentrations of neutrocytes, lymphocytes, epinephrine, ACTH or cortisol between the in-season HI and off-season LO tests; however, norepinephrine and the IL-6 concentrations were elevated at the in-season HI test compared to the off-season LO test. There were no significant differences in POMS global mood score or sub-scores between the in-season HI and the off-season LO tests. Thus, in a group of elite Nordic skiers, we conclude that a doubling of the training and competition load during the winter season does not alter the leukocyte and stress hormone responses to an incremental exercise test to exhaustion.

Adaptation, Physiological↗

Effects of hypothalamic-pituitary-adrenal axis reactivity on periodontal tissue destruction in rats.

The aim of this study was to test the hypothesis of an association between hypothalamic-pituitary-adrenal (HPA) axis reactivity and progression of periodontal disease. Histocompatible Lewis and Fischer 344 rats respond to stressful stimuli with low and high HPA axis reactivity, respectively. Experimental periodontitis was induced by tying a silk ligature around the neck of maxillary 2nd right molar teeth in 10 Lewis and 10 Fischer 344 rats with contralateral non-manipulated teeth as controls. Twenty non-manipulated animals were included. Also, experimental periodontitis was induced in 10 adrenalectomized Wistar rats and in 10 sham-operated rats. Furthermore, corticosterone pellets were subcutaneously implanted in 9 Lewis rats, while placebo pellets were implanted in 8 animals. Disease progression was evaluated histometrically and radiographically. The low-responding Lewis rats developed significantly less periodontal breakdown than did the high-responding Fischer 344 rats. Administration of corticosterone increased the disease development. while adrenalectomy reduced the disease severity. Our findings demonstrate the importance of genetic factors in the development of periodontal disease, and suggest that HPA axis hyper-activation is one mechanism by which periodontal disease susceptibility may be increased.

Adrenal Cortex Hormones↗

Glucocorticoid receptor antagonist RU 486 treatment reduces periodontitis in Fischer 344 rats.

Inappropriate hypothalamic pituitary adrenal (HPA) axis regulation of immune responses to bacterial challenges has been found to play an important role in infections and inflammatory disease susceptibility and progression. In the present study we investigated the tissue effects of experimental periodontitis in Fischer 344 rats, which were subcutaneously (s.c.) injected with 20 mg/kg of the glucocorticoid receptor antagonist and active antiglucocorticoid agent RU 486 every second day over a period of 14 d. Periodontitis was induced by placing a bacterial plaque retentive silk ligature in the gingival sulcus around the neck of maxillary right 2nd molar teeth 1 d after the first injection in 10 RU 486-treated and 10 vehicle (1,2-propanediol)-treated control animals. The contralateral maxillary left 2nd molars served as internal control teeth for naturally occurring periodontitis. Disease progression was evaluated radiographically and histometrically. The average level of corticosterone in blood at sacrifice was significantly lower in the RU 486-treated animals as compared to controls. The experimental animals also developed significantly less periodontal breakdown at both experimental and control teeth compared to the vehicle-treated control animals. The results support our recent findings showing that HPA hyper-reactivity, either genetically determined or experimentally induced, stimulates periodontal disease susceptibility. These findings suggest that central nervous regulation of inflammatory responses to dental plaque microorganisms in the gums may modulate periodontal disease susceptibility and progression.

Animals↗

Intestinal IgA- and IgM-producing cells are not decreased in marathon runners.

Alterations in duodenal immunoglobulin (Ig-)producing cells after excessive physical stress (marathon running) were studied by immunohistochemistry in 11 well-trained male adults, both shortly after running (race time, approximately 3.00 h) and later on after a "resting period" of 8-12 weeks with normal training (7-20 h/week). The ratios of IgA-, IgM- and IgG-producing cells were similar in the two biopsy specimens and virtually identical to those in eight normal duodenal controls (medians 77.6% IgA, 18.6% IgM, and 2.5% IgG). However, in the first sample the total number of positive cells per intestinal length unit was increased in five for IgA and in seven for IgM, while it was decreased in eight for IgG compared with the second biopsy. Also, the IgA cell number tended to be slightly increased immediately after the race (median 128 cells/unit) compared with that in normal controls (median 111 cells/unit); the same tendency was found for all Ig classes considered together. This apparent change was not explained by a thickening of the mucosa. Our study showed that marathon runners seem to maintain or even enhance their intestinal IgA and IgM-production, in contrast to the IgA decrease reported for other compartments such as salivary secretions and peripheral blood. The tendency to slightly increased intestinal IgA and IgM immunocyte populations in some runners might reflect a stress-induced hormonal influence on the homing of primed B cells to the mucosa, or perhaps an immune response to elevated influx of stimulatory luminal antigens.

Adolescent↗

Granulocyte chemiluminescence response to serum opsonized zymosan particles ex vivo during long-term strenuous exercise, energy and sleep deprivation in humans.

The chemiluminescence response of granulocytes to serum opsonized zymosan particles (SOZ) ex vivo was investigated during two ranger training courses lasting 7 days with continuous moderate physical activities corresponding to about 32% of maximal oxygen uptake or 35000 kJ.24 h-1, with energy deficiency (energy supply 0-4000 kJ.24 h-1), and less than 3-h sleep during the 7 days. Significant granulocytosis in combination with a lymphopenia in peripheral blood was observed during the whole course. A priming of the granulocytes for accentuated chemiluminescence response to SOZ was observed during the first days of the course with a maximal increase on day 3 in course A (+35% of control response) and on day 1 in course B (+12%). Thereafter, reduced responses to SOZ compared to control values (-28% and -21% in course A and B) were observed. In course A, a group (n = 8) receiving 5000 kJ.24 h-1 of additional energy, showed a more pronounced priming (maximum +57% versus +21% of control response) during the first days. In course B, all the cadets had 3 h of organised rest/sleep on day 5, and a second priming of the chemiluminescence response was observed on the subsequent 2 days. These data indicated that moderate, continuous, predominantly aerobic physical activities for 1-3 days around the clock primed the production of reactive oxygen species in granulocytes. This priming may be beneficial for, for example, host defence against micro-organisms, but may also contribute to inflammatory damage to normal tissues such as muscle, tendons and joints during exercise. However, when the moderate exercise continued for several more days, a down-modulation of the granulocyte response was observed. The findings of this study further support the possibility that moderate physical activity stimulates immunity, while more extreme duration of the same activities may result in a down-modulation of non-specific (and specific) immunity.

Blood↗

The effect of strenuous exercise, calorie deficiency and sleep deprivation on white blood cells, plasma immunoglobulins and cytokines.

Moderate exercise appears to stimulate the immune system, but there is good evidence that intense exercise can cause immune deficiency. In the present study the authors examined the effect of continuous physical exercise (35% of VO2 max), calorie deficiency and sleep deprivation on the immune system of young men participating in a 5-7 days military training course. There was a two-three fold increase of neutrophils from day 1, the values remained high and decreased slightly at the end of the course. Monocyte counts also increased with a pattern similar to that of neutrophils. Eosinophils decreased to 30% of control and lymphocyte numbers decreased by 30-40%. All the major subgroups (CD4 T cells, CD8 T cells, B cells, NK cells) were reduced. Neutrophil function, as tested by measuring chemotaxis, was significantly stimulated during the first days of the course, in particular in the group with the lowest calorie intake. The mitogenic response of lymphocytes to PHA and Con A was variable, ranging from stimulation during one course to no effect in another course. Serum levels of immunoglobulins decreased significantly during the course. IgG was reduced by 6-7%, IgA by 10-20% and IgM by 20-35%. The authors found no changes of interleukin 1, 2 and 4 during the course, but a (12-20%) reduction (P less than 0.01) of interleukin 6, and an increase (P less than 0.01) of granulocyte-macrophage colony stimulating factor. Altogether the results from the ranger course present a mixed-up picture. The non-specific phagocyte-related immunity was enhanced. On the other hand, the data indicate that even a moderate physical activity, around the clock, caused significant suppression of a number of parameters reflecting the status of the specific, lymphocyte-related immunity. It is noteworthy, however, that there was no significantly increased infection rate during the course or in the first 4-5 weeks thereafter.

Acute-Phase Proteins↗

Effect of in vivo corticosterone and acute food deprivation on rat resident peritoneal cell chemiluminescence after activation ex vivo.

Adrenoglucocorticoid regulation of rat peritoneal monocyte/macrophage function was studied by exposing rats to corticosterone (CS) in the drinking water, and to fast (48 h). Production of reactive oxygen metabolites was measured by luminol amplified chemiluminescence (CL) in preparations of peritoneal cells activated by serum treated zymosan (STZ). Administration of CS which led to an increase in plasma CS from 31 (controls) to 46 ng mL-1, reduced CL (per cell) by 31%. Fast, which did not change plasma CS or ACTH, also had an inhibitory effect on CL (-25%), while the combination of CS administration and fast strongly inhibited the CL (-89%), indicating that plasma CS and fast reduced CL in a synergistic way. Similar effects on cell number were observed: CS-administration, fast and the combination reduced macrophage numbers (-13, -19.7 and -55%), while no significant effect was observed on the number of monocytes. The effect of adrenalectomy (adx) was studied in another series of experiments; adx induced no significant change in peritoneal leucocyte number or composition, while cells from adx animals had significantly higher chemiluminescence reaction than cells from sham operated animals. CS substitution in adx animals reduced CL by 30% while sham operated animals had 49% lower CL in adx. The data from adx animals also suggest that endogenous levels of CS are inhibitory for CL, but the results are not conclusive for the effect of very low doses of CS since other mechanisms than elimination of CS could prime the chemiluminescence reaction after adx. In conclusion, a moderate elevation of CS after systemic administration in vivo reduced the total number of mononuclear phagocytes in rat peritoneum, reduced the relative number of macrophages compared with monocytes, and suppressed the function of monocytes/macrophages by reducing the production of reactive oxygen molecules in activated cells. Furthermore, the effect of corticosterone was also dependent on the physiological situation, since the effects of fast and corticosterone were synergistic.

Adrenalectomy↗

Atrial natriuretic peptide in plasma after prolonged physical strain, energy deficiency and sleep deprivation.

Plasma concentrations of atrial natriuretic peptide (ANP) were investigated daily in 16 male cadets during a 6-day military training course with continuous heavy physical activities, sleep and energy deficiency (course I). At the end of another similar course (course II) 15 cadets were studied during 30-min cycle exercise at 50% maximal oxygen uptake with and without glucose infusion. A small, but not significant increase was found in the plasma concentrations of ANP during course I from 9.6 (SEM 1.1) pmol.l-1 in the control experiment to 11.1 (SEM 0.5) pmol.l-1 on day 5. During course II a small but significant increase was found from 7.8 (SEM 0.5) pmol.l-1 in the control experiment to 9.1 (SEM 0.5) pmol.l-1 at the end of the course. Plasma osmolality and chloride concentration decreased during the course. During the exercise test a significant increase was seen in ANP concentration from 8.2 (SEM 0.8) to 13.1 (SEM 2.0) pmol.l-1 in the control experiment and from 9.4 (SEM 0.7) to 13.5 (SEM 1.2) pmol.l-1 during the course. This response was attenuated by glucose infusion, an effect which may have been due to an exercise induced increase in plasma chloride concentration being abolished. In contrast, the potassium concentration response to exercise was increased during the course but unaffected by glucose infusion. In conclusion, the large increases in endogenous plasma catecholamine concentration shown to take place during previous courses were not reflected in the plasma concentrations of ANP, indicating only a moderate cardiac stress or no cardiac work overload during such courses.

Adult↗

Adrenaline stimulated cyclic adenosine monophosphate response in leucocytes is reduced after prolonged physical activity combined with sleep and energy deprivation.

The mechanism for adrenergic desensitisation during physical stress was studied by measuring [125I] cyanopindolol ([125I]CYP) binding sites and the adrenaline stimulated cyclic adenosine monophosphate (cAMP) responses in peripheral blood leucocytes from ten male cadets during a 5-day military training course. The cadets had physical activities around the clock corresponding to a daily energy consumption of about 40,000 kJ but with an intake of only 2,000 kJ, and only 1-3 h of sleep in the 5 days. During the course, the maximal cAMP response to adrenaline stimulation was reduced to about 45% in granulocytes and to 52% in mononuclear cells, and the half maximal response was obtained only at 5-10 times higher adrenaline concentrations than in the control experiment. The binding sites for [125I]-CYP in mononuclear cells increased during the course. However, [125I]-CYP measured not only surface receptors but also intracellular receptors and might even have represented other binding sites. In conclusion, this study showed that decreased cAMP response to adrenergic stimulation would seem to be one of the mechanisms behind adrenergic desensitisation during stress.

Adrenergic beta-Antagonists↗

[Overtraining among elite athletes--causes, diagnosis and treatment].

Overtraining is an imbalance between training and recovery. We review the pathogenesis of overtraining, with emphasis on the neuroendocrinal changes which occur in response to acute overtraining. At present, no sensitive and specific tests are available to allow early diagnosis of overtraining. The diagnosis is based on medical history, clinical evaluation and exercise testing. The treatment is rest, and may take weeks to months.

Athletic Injuries↗

The effect of glucose on the plasma concentration of somatostatin during caloric deficiency in man.

Somatostatin produced in the D-cells of the stomach and the pancreas plays an important role in the carbohydrate metabolism and has been suggested to be involved in the disturbed glucose homeostasis during starvation. We investigated two groups of subjects during severe caloric deficiency. Nine healthy subjects (mean age, 32 years) fasted for 4 days, and the plasma concentration of somatostatin increased greatly, from 11.0 +/- 1.3 pM to 21.7 +/- 2.3 pM (p = 0.001). Intravenous infusion of 50 g glucose after a 60-h fast and oral loading of 50 g glucose after an 80-h fast normalized temporarily the plasma concentration within 45 min and 60 min, respectively. In another group of 12 subjects (mean age, 34 years), who participated in a 90-km cross-country ski race lasting 4.45-6.50 h and who were suspected of being in severely catabolic metabolic state, the plasma concentration of somatostatin increased from 6.1 +/- 0.8 pM to 26.9 +/- 4.7 pM (p < 0.001). Post-race oral feeding of 100 g glucose in seven of the subjects normalized the plasma concentration within 30 min, but the concentration remained increased in the five subjects who had no post-race caloric supply. The results indicate a close relationship between somatostatin and glucose during caloric deficiency in man.

Adult↗