Cytokine modulation of pituitary hormone secretion

Hormonal changes in veterans with Gulf War Illness

AIMS

Gulf War Illness (GWI) is a multi-system condition of complex etiology and pathophysiology without specific treatment. There is an overlap between the symptoms of GWI and endocrinopathies. This study aimed to identify hormonal alterations in 1990-91 Gulf War (GW) veterans and the relationship between GWI and hormonal dysregulation.

MAIN METHODS

Data from 81 GW veterans (54 with GWI and 27 controls without GWI) was analyzed in a cross-sectional, case-control observational study. Participants completed multiple questionnaires, neuropsychiatric assessments, and a comprehensive set of hormone assays including a glucagon stimulation test (GST) for adult growth hormone deficiency (AGHD) and a high-dose adrenocorticotropic hormone (ACTH) stimulation test for adrenal insufficiency.

KEY FINDINGS

The GWI group had lower quality of life and greater severity of all symptoms compared to controls. Pain intensity and pain-related interference with general activity were also higher in the GWI group. AGHD was observed in 18 of 51 veterans with GWI (35.3 %) and 2 of 26 veterans without GWI (7.7 %) (p = 0.012 for interaction). Veterans with GWI also exhibited reduced insulin-like growth factor 1 (IGF-1) levels and IGF-1 Z-scores compared to controls. One participant with GWI met the criteria for adrenal insufficiency. No significant changes were observed in other hormonal axes.

SIGNIFICANCE

The frequency of AGHD was significantly higher in veterans with GWI compared to controls. Recombinant human growth hormone replacement therapy (GHRT) may become a breakthrough therapeutic option for this subgroup. A large clinical trial is needed to evaluate the efficacy of GHRT in patients with GWI and AGHD.

Increased pain and inflammatory sensitivity in growth hormone-releasing hormone (GHRH) knockout mice

Growth hormone (GH) and GH-releasing hormone (GHRH), in addition to metabolic and endocrine effects, play a role in the modulation of pain and inflammation. We aimed to elucidate the consequences of GHRH deficiency on acute nociceptive stimulation and on both acute and chronic inflammatory stimuli in a mouse model of GH deficiency. Mice with generalized ablation of the GHRH gene (GHRH knock out, GHRHKO, -/-) were compared to wild type (GHRH +/+) mice. Responsiveness to acute nociceptive stimulation and to acute inflammatory stimulation was evaluated by conventional hot plate apparatus and formalin test, respectively. We also evaluated responsiveness to colonic inflammation induced both in vivo, after dextran sodium sulfate (DSS) treatment, or ex vivo, by incubating colon segments with bacterial lipopolysaccaride (LPS). Macroscopical and histological examinations were performed, prostaglandin (PG) E₂ and 8-iso-PGF_2α levels and cyclooxigenase (COX)-2 and tumor necrosis factor (TNF)-α gene expression were measured. Compared to controls, -/- mice showed decreased response latency during the hot plate test, and increased licking/biting time in formalin test, particularly in the second phase of inflammation. DSS treated -/- mice showed a significant increase of colonic inflammation compared to controls. Moreover DSS treatment increased PGE₂ and 8-iso-PGF_2α levels, along with COX-2 and TNF-α gene expression more markedly in colon specimens of -/- mice compared to controls. LPS-induced PGE₂ and 8-iso-PGF_2α production from colonic segments incubated ex vivo was also increased in -/- mice. Generalized GHRH gene ablation increases sensitivity to thermal pain and both acute and persistent inflammatory stimuli in male mice.

Interactions between the growth hormone and cytokines - A review

Numerous reports on the interactions between the immune and endocrine systems, especially growth hormone axis, can be found in the literature. Growth hormone acts mainly indirectly through insulin-like growth factor-1, which stimulates the growth and development processes, metabolism of lipids, proteins, and carbohydrates, and it also has a modulating effect on the cells of the immune system. Several studies have been conducted on the influence of growth hormone therapy on the immunological parameters in children and adults with and without growth hormone deficiency. However, there have been no definite results and some of them have been even contradictory. Some studies have suggested that administration of growth hormone increases the production of tumor necrosis factor and certain pro- and anti-inflammatory cytokines; whereas other studies have demonstrated the lack of correlation between growth hormone and interleukins. The aim of this paper was to evaluate the available literature on the interaction between growth hormone and TNF-α, pro-inflammatory (IL-1β, IL-2, IL-6) and anti-inflammatory (IL-4, IL-10) interleukins.

Therapeutic efficacy of antibiotic-loaded gelatin microsphere/silk fibroin scaffolds in infected full-thickness burns

Despite advances in burn treatment, burn infection remains a major cause of morbidity and mortality. In this study, an antibacterial silk fibroin (SF) scaffold for burn treatment was designed; gelatin microspheres (GMs) were impregnated with the antibiotic gentamycin sulfate (GS), and the GS-impregnated GMs were then embedded in a SF matrix to fabricate GS/GM/SF scaffolds. The developed GS/GM/SF scaffolds could serve as a dermal regeneration template in full-thickness burns. The average pore size and porosity of the GS/GM/SF scaffolds were 40-80 μm and 85%, respectively. Furthermore, the drug release rate of the scaffolds was significantly slower than that of either GS/GM or GS/SF scaffolds. And the composite scaffold exhibited stronger antimicrobial activities against Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa. Hence, we evaluated the wound-healing effects and antibacterial properties of the GS/GM/SF scaffolds in a rat full-thickness burn infection model. Over 21 days, the GS/GM/SF scaffolds not only significantly reduced burn infection by P. aeruginosa but also accelerated the regeneration of the dermis and exhibited higher epithelialization rates than did GS/SF and SF scaffolds. Thus, GS/GM/SF scaffolds are potentially effective for treatment of full-thickness infected burns, and GS/GM/SF scaffolds are a promising therapeutic tool for severely burned patients.

Spinal-general anaesthesia decreases neuroendocrine stress response in laparoscopic cholecystectomy

OBJECTIVE

A randomized clinical study to compare the stress response to laparoscopic cholecystectomy during spinal-general anaesthesia and epidural- general anaesthesia.

METHODS

Women undergoing elective laparoscopic chole cystectomy were assigned to receive either spinal anaesthesia (SA group; n = 12) or epidural anaesthesia (EA group; n = 12), in addition to general anaesthesia. Plasma concentrations of cortisol, adrenocorticotrophic hormone (ACTH), noradrenaline, adrenaline and total catecholamines were measured pre- and intraoperatively.

RESULTS

Intraoperative cortisol, noradrenaline and total catecholamine levels were significantly lower in the SA group compared with the EA group. When pre- and intraoperative values were compared, the SA group showed a decrease in adrenaline, noradrenaline and total catecholamine levels, and the EA group showed an increase in ACTH and noradrenaline levels.

CONCLUSIONS

The type of regional anaesthesia significantly affected the stress response: spinal anaesthesia produced a more favourable endocrine response than epidural anaesthesia. Spinal-general anaesthesia may reduce postoperative morbidity in laparoscopic cholecystectomy.

Cytokines in recurrent pregnancy loss

BACKGROUND

Recurrent pregnancy loss (RPL) is defined as the occurrence of three or more consecutive miscarriages prior to 20 weeks gestation. Exaggerated maternal immune response to fetal antigens has been proposed to be one of the mechanisms underlying recurrent pregnancy loss.

METHOD

A comprehensive literature search was conducted from the websites of the National Library of Medicine (http://www.ncbl.nlm.nih.gov) and Pubmed Central, the US National Library of Medicine's digital archive of life sciences literature (http://www.pubmedcentral.nih.gov/). The data was assessed from books and journals that published relevant articles in this field.

RESULT

In normal pregnancy, tolerance of the genetically incompatible fetus by the maternal immune system depends on the interactions of an array of cytokines secreted by maternal and fetal cells at the site of implantation. Earlier research indicated that altered immunity in RPL is dominated by the Th1/Th2 hypothesis, which proposed that the fetus escapes maternal-derived T-cell responses through skewing the Th0 differentiation toward Th2 pathway which dampens pro-inflammatory Th1-type immunity. Recent studies indicate the role of proinflammatory Th17 cells and immunoregulatory Treg cells in RPL in addition to Th1/Th2 interactions.

CONCLUSION

Cytokines form a complex regulatory network which maintains homeostasis between the fetal unit and the maternal immune system. If this delicate balance is adversely affected, immunoregulatory mechanisms may be insufficient to restore homeostasis and this may lead to pregnancy failure.

Factors that affect postnatal bone growth retardation in the twitcher murine model of Krabbe disease

Krabbe disease is an inherited lysosomal disorder in which galactosylsphingosine (psychosine) accumulates mainly in the central nervous system. To gain insight into the possible mechanism(s) that may be participating in the inhibition of the postnatal somatic growth described in the animal model of this disease (twitcher mouse, twi), we studied their femora. This study reports that twi femora are smaller than of those of wild type (wt), and present with abnormality of marrow cellularity, bone deposition (osteoblastic function), and osteoclastic activity. Furthermore, lipidomic analysis indicates altered sphingolipid homeostasis, but without significant changes in the levels of sphingolipid-derived intermediates of cell death (ceramide) or the levels of the osteoclast-osteoblast coupling factor (sphingosine-1-phosphate). However, there was significant accumulation of psychosine in the femora of adult twi animals as compared to wt, without induction of tumor necrosis factor-alpha or interleukin-6. Analysis of insulin-like growth factor-1 (IGF-1) plasma levels, a liver secreted hormone known to play a role in bone growth, indicated a drastic reduction in twi animals when compared to wt. To identify the cause of the decrease, we examined the IGF-1 mRNA expression and protein levels in the liver. The results indicated a significant reduction of IGF-1 mRNA as well as protein levels in the liver from twi as compared to wt littermates. Our data suggest that a combination of endogenous (psychosine) and endocrine (IGF-1) factors play a role in the inhibition of postnatal bone growth in twi mice; and further suggest that derangements of liver function may be contributing, at least in part, to this alteration.

Psyche and soma: New insights into the connection

The interaction of Psyche and Soma are well known and this interaction happens through a complex network of feedback, medication, and modulation among the central and autonomic nervous systems, the endocrine system, the immune system, and the stress system. These systems, which were previously considered pristinely independent, in fact, interact at myriad levels. Psychoneuroimmunology (PNI) is an emerging discipline that focuses on various interactions among these body systems and provides the underpinnings of a scientific explanation for what is commonly referred to as the mind-body connection. This article reviews the relevant literature with an emphasis on Indian research.

Comparison of Stress Hormone Response, Interleukin-6 and Anaesthetic Characteristics of Two Anaesthetic Techniques: Volatile Induction and Maintenance of Anaesthesia using Sevoflurane versus Total Intravenous Anaesthesia using Propofol and Remifentanil

This prospective randomized study compared the effects of two types of anaesthesia on peri-operative anaesthetic profiles from induction to recovery and on immunological and neurohormonal responses to anaesthesia and surgical stress. Forty patients were assigned to undergo either volatile induction and maintenance of anaesthesia (VIMA) with sevoflurane or total intravenous anaesthesia (TIVA) with propofol and remifentanil. Plasma adrenaline, noradrenaline, cortisol, glucose and interleukin-6 (IL-6) levels were measured at baseline, induction, incision and extubation. TIVA produced a significantly lower intubation score, shorter time to intubation and faster waking time than VIMA, but recovery profiles did not differ. Adrenaline, noradrenaline, cortisol and glucose levels were significantly lower with TIVA than VIMA, but there was no difference in IL-6 levels between the two groups. TIVA with propofol and remifentanil may be preferable to VIMA with sevoflurane alone because it leads to smoother, more rapid induction, more rapid awakening and lower stress responses to surgical stimuli.

Serum leptin levels following acute experimental spinal cord injury

BACKGROUND/OBJECTIVE

Spinal cord injury influences many hormones that are known to be involved in the modulation of neurotrophic, neurogenic, and neuroprotective events. Recent studies showed that leptin could be neuroprotective, enhancing neuronal survival in vitro and in vivo. The objective of this study was to evaluate the pattern of the serum leptin levels in rats during acute traumatic SCI.

METHODS

Forty male Sprague-Dawley rats were divided randomly into 4 groups. In the control group, neither laminectomy nor SCI was performed; only laminectomy was performed without SCI in the sham group. In the cervical and thoracic spinal trauma groups, laminectomies were performed following the same trauma procedure. Blood samples were drawn 2, 6, 12, and 24 hours after the procedures and assayed immediately.

RESULTS

In the first 2 hours, levels of leptin were similar in control and sham-operated groups and higher in neurotrauma groups (P < 0.05). At the sixth hour, leptin levels increased in the sham-operated group, decreased in the neurotrauma groups (P < 0.05), and did not change in the control group (P > 0.05). At the 12th hour, the levels of leptin increased in all groups (P > 0.05). At the 24th hour, they decreased in the control, sham-operated, and cervical groups (P < 0.05); levels did not change in the thoracic group (P > 0.05). The decrease was higher in the control group than in the other groups (P < 0.05).

CONCLUSIONS

Activation of endogenous leptin secretion started immediately after the SCI. The level of neurologic lesion (either cervical or thoracic regions) affected the levels of serum leptin differently, but with the exception of the first 12-hour period, this difference did not reach a statistically significant level.

Serum levels of cortisol and prolactin in patients treated under total intravenous anesthesia with propofol-fentanyl and under balanced anesthesia with isoflurane-fentanyl

The study was designed to determine pre-, intra-and postoperative serum cortisol and prolactin (PRL) concentrations in patients subjected to low abdominal surgery under total intravenous anesthesia (TIVA) with propofol-fentanyl, and under general balanced anesthesia with isoflurane-fentanyl. The prospective study included 50 patients of both sexes, aged between 35 and 60 years, subjected to elective low abdominal surgery. Patients were randomly divided into two groups: an experimental group, consisting of 25 ASA I/II (American Society of Anesthesiologists I/II classification) patients treated under TIVA with propofol-fentanyl, and a control group consisting of 25 ASA I/II patients treated under balanced anesthesia with isoflurane-fentanyl. The length of the surgery and the degree of the surgical trauma did not differ significantly between the two anesthesia groups. Blood samples for cortisol and PRL measurements were drawn at exact time points: 30 minutes before the beginning of the surgery (T0), 30 minutes after the beginning of the surgery (T1), at the end of the surgery (T2), 2 hours after the surgery (T3), and 24 hours after the surgery (T4). Serum levels of cortisol and PRL were measured using commercially available kits. The results were evaluated with the nonparametric Mann-Whitney test. The serum concentration of cortisol measured at T1 time point in patients treated under TIVA was significantly lower (p=0.04) than that in patients treated under general balanced anesthesia. The average circulating levels of PRL measured at T1, T2 and T3 time points in patients treated under TIVA were significantly lower (p=0.003; p=0.002; p<0.05; respectively) than those in patients treated under balanced anesthesia. The results obtained suggest that the endocrine stress response developed in response to surgery is probably attenuated in patients treated under TIVA with propofol-fentanyl and, thus, that these patients are less stressed in comparison to patients treated under general balanced anesthesia with isoflurane-fentanyl.

Leptin and perioperative neuroendocrine stress response with two different anaesthetic techniques

BACKGROUND

Stress response to surgery is modulated by several factors, including magnitude of the injury, pain, type of procedure and choice of anaesthesia. Our purpose was to compare intra- and post-operative hormonal changes during total intravenous anaesthesia (TIVA) using propofol and remifentanil vs. sevoflurane anaesthesia in a low stress level surgical model (laparoscopy).

METHODS

We randomly allocated 18 patients undergoing laparoscopic surgery for benign ovarian cysts in two groups to receive either TIVA (group A=9) or sevoflurane anaesthesia (group B=9). Perioperative plasma levels of norepinephrine (NE), epinephrine (E), adrenocorticotropic hormone (ACTH), cortisol and leptin were measured. Blood samples were collected pre-operatively (time 0), 30 min after the beginning of surgery (time 1), after extubation (time 2), and 2 h (time 3) and 4 h after surgery (time 4).

RESULTS

The comparative analysis between the groups shows significantly higher values of NE (P<0.001 at time 1 and P<0.01 at time 3), E (P<0.001 at times 1 and 2; P<0.01 at time 3 and P<0.05 at time 4), ACTH (P<0.001 at times 1 and 2; P<0.05 at time 3) and cortisol (P<0.001 at times 1 and 2; P<0.01 at time 3; P<0.05 at time 4) in group B. The serum values of leptin were not significantly different between the two groups.

CONCLUSION

The choice of anaesthesia does not seem to affect the leptin serum levels but influences the release of stress response markers: ACTH, cortisol, NE and E.

Khat (Catha edulis) lowers plasma luteinizing hormone (LH) and testosterone secretion, but increases cortisol levels in male rabbits

AIM

This study investigated the effects of fresh khat extract on specific circulating hormones in male rabbits.

MATERIALS AND METHODS

A total of 25 male New Zealand White rabbits were divided into five groups each comprising five animals. The first four groups were fed four doses (1.5 g/kg, 4.5 g/kg, 13.5 g/kg and 40.5 g/kg body weight) of khat extract twice a week for 5 weeks while the last group, serving as control, was fed only normal saline via intragastric tube. Blood samples were collected at 15 min interval for up to 3 h after khat extract administration and plasma assayed for luteinizing hormone (LH), testosterone and cortisol levels using radioimmunoassay technique.

RESULTS

Khat extract at all doses significantly lowered (P<0.05) LH pulse frequency, area under LH curve, mean plasma LH and mean plasma testosterone levels. Plasma cortisol levels were significantly elevated (P<0.05) in khat-treated rabbits in a dose-dependent manner.

CONCLUSION

This study demonstrates that khat may impair reproductive function in male rabbits by interfering with sex hormone profiles.

Remifentanil for cesarean section under general anesthesia: effects on maternal stress hormone secretion and neonatal well-being: a randomized trial

BACKGROUND

Remifentanil may attenuate maternal hemodynamic response during cesarean section under general anesthesia, but could cause transient but significant neonatal depression. We investigated the effect of low-dose remifentanil on maternal neuroendocrine response and fetal wellbeing.

METHODS

Forty-two ASA I-II parturients undergoing cesarean section at term under general anesthesia were randomized to receive either fentanyl after delivery (n=21, group C) or remifentanil bolus 0.5 microg/kg before induction followed by a continuous infusion at 0.15 microg x kg(-1)min(-1) until peritoneal incision, then restarted after delivery (n=21, group R). Maternal heart rate and blood pressure, and epinephrine, norepinephrine, adrenocorticotropic hormone (ACTH), and growth hormone levels were measured at baseline, uterine incision, and the end of surgery. Remifentanil was measured in maternal and umbilical arterial and venous blood. One- and 5-minute Apgar scores and umbilical arterial and venous pH were recorded.

RESULTS

ACTH was significantly higher in group C at uterine incision (P<0.01). No significant differences were observed in hemodynamics, catecholamines or growth hormone. Apgar scores at 1 (P<0.05) and 5 min (P<0.01) were significantly higher in group C. Mean umbilical pH values were within normal range but significantly higher in group C. Three neonates in group R required intubation but recovered at 5 min without naloxone. Mean+/-SD maternal remifentanil concentration was 1.67+/-1.04 ng/mL.

CONCLUSIONS

Remifentanil administration before peritoneal incision partially reduced the hormonal stress response. Maternal benefits must be weighed against transitory but significant neonatal respiratory depression. Neonatal resuscitation facilities are mandatory when remifentanil is used.

TNF-alpha levels in children with growth hormone deficiency and the effect of long-term growth hormone replacement therapy

OBJECTIVE

Growth hormone (GH) has been suggested to modulate the release of some cytokines including TNF-alpha. To investigate TNF-alpha levels in children with GH deficiency (GHD), to evaluate alteration in TNF-alpha levels during recombinant human GH (rhGH) treatment, and to analyze possible correlations between TNF-alpha and GH, IGF-1 and IGFBP-3.

DESIGN

Twenty-four children, aged 12.60+/-2.27 years, with isolated GHD and given rhGH therapy, as subcutaneous ingestion of 0.03-0.04mg/kg once-daily dose, were evaluated. Eleven had complete and 13 had partial GHD. Thirty-three healthy children were studied as controls. Age and sex distribution, body mass indexes of two groups were similar. In children with GHD, blood samples were drawn before (TNF-alpha0), and at 6 (TNF-alpha6) and 12 (TNF-alpha12) months of the treatment with rhGH. TNF-alpha was determined using a human TNF-alpha ELISA assay (Biosource International).

RESULTS

TNF-alpha0 levels were significantly higher in children with GHD than in controls (41.79+/-25.04 and 8.63+/-4.48pg/ml, respectively, p<0.001) and decreased significantly during rhGH treatment (TNF-alpha0=41.79+/-25.04, TNF-alpha6=13.67+/-9.95, TNF-alpha12=10.86+/-6.61pg/ml, p<0.05). There was no correlation between TNF-alpha levels and BMI, IGF-1/logIGF1, IGFBP-3 levels and growth velocity of the patients with GHD. Although no correlation between TNF-alpha and peak GH levels after stimulation was present; a moderate reverse correlation between TNF-alpha and basal serum concentrations of GH (r=-0.512, p=0.046) was demonstrated.

CONCLUSIONS

TNF-alpha levels are significantly higher in children with GHD than the controls, and long-term therapy with rhGH effectively reduces its level. Our data suggest that GH plays an inhibitory role on TNF-alpha release in humans. However, due to inconsistent results up to now, further prospective, controlled and long term studies are needed to elucidate the issue.

Anesthetic Requirements and Stress Hormone Responses in Spinal Cord-Injured Patients Undergoing Surgery Below the Level of Injury

Neuraxial anesthesia decreases the minimum alveolar concentration. We determined the effects of spinal cord injury (SCI) on sevoflurane requirements and stress hormone response. Twenty-two chronic SCI patients undergoing surgery below the level of the injury were enrolled in the study, and 15 patients without cord injury served as control patients. Bispectral index score was maintained at 40-50. Measurements included end-tidal sevoflurane concentrations, systolic arterial blood pressure, heart rate, and plasma catecholamine and cortisol concentrations. During surgery, systolic arterial blood pressure, heart rate, and Bispectral index were comparable between SCI and control groups. However, end-tidal sevoflurane concentration was significantly smaller in the SCI (0.81%-1.06%) versus control (1.28%-1.31%) patients. In the control group, plasma norepinephrine and cortisol concentrations were significantly increased during and 1 h after surgery compared with awake baseline values. In the SCI group, the sympathoadrenal and cortisol responses were virtually abolished. We conclude that SCI reduces the anesthetic requirement by 20%-39% during surgery below the level of injury, in association with blunted sympathoadrenal and cortisol responses.

Adrenal axis functions in patients with familial Mediterranean fever

OBJECTIVE

Familial Mediterranean fever (FMF) is a hereditary disease characterized by recurrent attacks of fever with peritonitis, arthritis, pleuritis or erysipelas-like rash. It is unclear what effects of FMF itself on endocrine system and hormones are. None of the FMF patients without amyloidosis have been reported to have any endocrine disorders, except those who developed colchicine-induced diabetes insipidus. There is a large body of evidence to show that cytokines (IL-1, IL-6 and TNF-alpha) activate the hypothalamic-pituitary-adrenal (HPA) axis. We have designated this study to investigate the HPA axis in FMF patients without amyloidosis.

METHODS

Twenty-one patients with FMF were included. ACTH stimulation test was performed on the healthy subjects and during attack period in the patients. In the patient group, same test was repeated during remission period.

RESULTS

Peak cortisol levels were significantly higher in the attack period than those in the remission period of patients (p<0.05).

CONCLUSION

The cytokines play a role on the activation of the HPA axis; we thought the axis would be affected in this disease. The response of cortisol to 250 mug ACTH was significant in attack period when compared with remission period. This result reveals that HPA axis is more activated in an FMF attack. Previous studies suggest that the adrenal hormones increase in acute inflammatory events, and eventually, the changes on these hormones are related to TNF and IL-6 levels. During the FMF attack, HPA axis may be stimulated by cytokines. It seems that HPA axis is regulated normally in FMF patients.

Plasma bioactive LH and testosterone profiles in male New Zealand rabbits experimentally infected with Schistosoma mansoni

The effects of Schistosoma mansoni (S. mansoni) infection on plasma levels of bioactive luteinising hormone (LH) and testosterone in the New Zealand rabbit model were studied. S. mansoni infection significantly decreased the pulse frequency (P < 0.05), amplitude (P < 0.05), area under LH curve (P < 0.05) and mean plasma LH concentrations (P < 0.05) on days 42 and 70 post-infection, as compared to values for day 14 pre-infection. Areas under the response curves for plasma testosterone levels decreased significantly (P < 0.05) on days 42 and 70 post-infection in infected animals compared to day 14 pre-infection. In the praziquantel-treated group, the levels of LH and testosterone remained unchanged throughout the experimental period. The pulsatile secretion of LH was completely inhibited in S. mansoni-infected animals 70 days post-infection. These results suggest that the effects on reproductive gonadal hormones caused by S. mansoni in the rabbit model may partly be induced by alteration in pituitary synthesis or release of LH.

Growth hormone releasing hormone reverses endotoxin-induced localized inflammatory hyperalgesia without reducing the upregulated cytokines, nerve growth factor and gelatinase activity

During inflammatory processes, the hypothalamic-pituitary axis is activated which can subsequently result in analgesia. For example, hypothalamic corticotrophin-releasing hormone (CRH) that is released during such activation has been attributed with analgesic actions. It is believed that the somatotrophic axis is also activated during inflammation. The aim of this study was to determine the analgesic actions of growth hormone-releasing hormone (GHRH), in a rat model of localized inflammatory hyperalgesia, induced by intraplantar (i.pl.) endotoxin (ET) injections. Pretreatment with intraperitoneal (i.p.) injections of GHRH (2, 5, 10 microg kg(-1)) 30 min before i.pl. ET injection (1.25 microg in 50 microl saline) prevented, in a dose-dependent manner, both mechanical hyperalgesia determined by the paw pressure (PP) test and thermal hyperalgesia determined by the hot plate (HP) and paw immersion (PI) tests. Pretreatment with GHRH had no significant effect on the elevated levels of the inflammatory mediators, interleukin (IL)-1beta, tumor necrosis factor (TNF)-alpha, IL-6 and nerve growth factor (NGF) due to i.pl. ET injection. No significant effect was obtained by pretreatment with GHRH, on the increased expression of gelatinase B due to ET injection. In conclusion, GHRH reverses inflammatory hyperalgesia in the rat without affecting the upregulated inflammatory mediators and these actions may be clinically important.

Neuroendocrine stress response in patients undergoing benign ovarian cyst surgery by laparoscopy, minilaparotomy, and laparotomy

STUDY OBJECTIVE

To quantify and compare neuroendocrine stress responses during and immediately after surgery by laparoscopy, minilaparotomy, and laparotomy for benign ovarian cysts.

DESIGN

Prospective study (Canadian Task Force classification II-1).

SETTING

Tertiary care university hospital.

PATIENTS

Thirty healthy women with no major diseases and without endocrine disorders.

INTERVENTIONS

Surgery for benign ovarian cysts performed by laparoscopy (10), minilaparotomy (10), or laparotomy (10).

MEASUREMENTS AND MAIN RESULTS

Venous blood samples were collected at fixed times as follows: at 8 A.M. in the ward before transferring the patient to the operating room (time 0), 30 minutes after the beginning of surgery (time 1), at the end of surgery after extubation with the patient awake (time 2), and 2 and 4 hours after the end of surgery (times 3 and 4). We evaluated intraoperative and postoperative variations of the following stress-related markers: norepinephrine (NE), epinephrine (E), adrenocorticotropic hormone (ACTH), human growth hormone (hGH), prolactin (PRL), and cortisol, and postoperative pain. No differences were present in demographic characteristics and operating times in the three groups. No anesthesiologic or surgical complications occurred. Postoperative pain was similar in the laparoscopy and minilaparotomy group but significantly higher in the laparotomy group (p <0.001). Serum levels of markers were not significantly different among the groups at baseline. In the laparoscopy group the increase of hGH was limited to intraoperative time (p <0.05); increases in NE, E, ACTH, and PRL were limited to intraoperative and early postoperative time after extubation (p <0.01), with only PRL persisting with significantly higher levels after the end of surgery (p <0.05). In the minilaparotomy group no increase was detected for hGH, a significant intraoperative increase in cortisol was present (p <0.05), and NE, E, ACTH, and PRL were significantly higher even after the end of surgery (p <0.01). In this group levels of NE, E, and hGH were significantly higher than in the laparoscopy group 2 and 4 hours after the end of surgery (p <0.05). In the laparotomy group significant intraoperative increases were present for all stress markers and persisted until after extubation for ACTH (p <0.01) and to the postoperative period for NE (p <0.01), E (p <0.01), cortisol (p <0.01), PRL (p <0.05), and hGH (p <0.01). In this group levels of NE, E, ACTH, and hGH were significantly higher than those in the laparoscopy group from the beginning (NE p <0.05, E p <0.01, ACTH p <0.05, hGH p <0.01) until after the end of surgery. Comparison of laparotomy and minilaparotomy groups showed the former to have significantly higher plasma levels of E, cortisol, and hGH in intraoperative and postoperative times (p <0.001); significantly higher NE at sampling times 1 and 2 (p <0.001) and time 4 (p <0.01), and no difference at sampling time 3; and ACTH significantly higher only during surgery (p <0.01).

CONCLUSION

Laparoscopic surgery causes minimal activation of stress hormones, which in some instances is confined to the intraoperative period. Minilaparotomy may be a valid alternative to laparoscopy in high-risk patients who cannot tolerate abdominal distention.

Sevoflurane improves the neuroendocrine stress response during laparoscopic pelvic surgery

PURPOSE

Stress response to surgery is modulated by several factors, including magnitude of the injury, type of procedure (e.g., laparoscopy vs laparotomy) and type of anesthesia. Our purpose was to compare intra- and postoperative hormonal changes during isoflurane vs sevoflurane anesthesia, in a clinical model of well defined operative stress (laparoscopic pelvic surgery).

METHOD

In this prospective randomized clinical study, 20 women requiring laparoscopic pelvic surgery for benign ovarian cysts received either a standard isoflurane plus fentanyl (Group A) or sevoflurane plus fentanyl anesthesia (Group B). Blood samples were collected preoperatively, 30 min after the beginning of surgery, at the end of surgery after extubation, and two and four hours after the end of surgery. Intra- and postoperative plasma levels of norepinephrine, epinephrine, adrenocorticotropic hormone (ACTH), cortisol, growth hormone (GH) and prolactin (PRL) were measured.

RESULTS

Catecholamine levels and postoperative pain were similar in both groups. Nonetheless, in comparison to Group A, Group B showed a significant decrease of ACTH, cortisol and GH levels (A vs B at the end of surgery: ACTH 160 +/- 45 vs 100 +/- 40 pg.mL(-1); cortisol 45 +/- 8 vs 23 +/- 7 microg.dL(-1); GH 3 +/- 2 vs 0.8 +/- 0.4 ng.mL(-1); P < 0.001 for all), but enhanced PRL levels (A vs B, at 30 min after the beginning of surgery: 139 +/- 54 vs 185 +/- 22 ng.mL(-1); at the end of surgery: 100 +/- 27 vs 141 +/- 45 ng.mL(-1); P < 0.001 for both).

CONCLUSIONS

In the clinical setting of low stress laparoscopic surgery, the type of volatile anesthetic significantly affected the stress response; the changes associated with sevoflurane suggested a more favourable metabolic and immune response compared to isoflurane.

Involvement of protein kinase C and tyrosine kinase in lipopolysaccharide-induced anorexia

Injections of lipopolysaccharide (LPS, 3 microg) into the lateral ventricle elicited anorexia with fever and also decreased body weight in rats. The LPS-induced anorexia was inhibited by intracerebroventicular (i.c.v.) injections of anti-interleukin (IL)-1beta antibody (Ab), chelerythrine, genistein and tyrphostin 46, but not by injections of indomethacin. Consecutive injections of orthovanadate and LPS (0.3 microg, a dose of LPS that did not show any effect on food intake, body weight or body temperature) reduced body weight, but did not induce anorexia. On the other hand, injections of IL-1beta (50 ng) did not influence food intake, although they decreased body weight and produced fever. The IL-1beta-induced decrease in body weight was inhibited by injections of genistein, but not by injections of chelerythrine or indomethacin. These findings suggest that the LPS-induced anorexia is independent of hyperthermia and involves IL-1beta generation, tyrosine kinase (TK) and protein kinase C (PKC). This is the first in vivo evidence that activation of TK and PKC induced by LPS is linked to anorexia.

Neuronal-associated tumor necrosis factor (TNF alpha): its role in noradrenergic functioning and modification of its expression following antidepressant drug administration

Tumor necrosis factor-alpha (TNF alpha) and the alpha 2-adrenergic agonist clonidine regulate norepinephrine (NE) release from noradrenergic nerve terminals in the central nervous system (CNS). In the present study, superfusion and electrical field stimulation were applied to a series of rat hippocampal brain slices in order to investigate the regulation of [3H]-NE release. NE release had been previously determined to be decreased by TNF alpha in a concentration-dependent manner, an effect which was potentiated by the alpha 2-adrenergic antagonist idazoxan. Presently, we demonstrate that similar to alpha 2-adrenergic activation, TNF alpha regulation of NE release in a region of the brain rich in noradrenergic nerve terminals, is dependent upon the frequency of electrical stimulation applied to the hippocampal slice. Furthermore, immunoperoxidase staining has verified our previous findings of constitutive TNF alpha protein in the rat brain. Staining for TNF alpha appears to be largely localized to neurons and neuronal processes, further substantiating the proposal that TNF alpha is either synthesized de novo or is accumulated in and released by neurons. After administration of the tricyclic antidepressant desipramine, tissue sections obtained from the rat hippocampus and locus coeruleus are devoid of neuronal-associated TNF alpha immunoreactivity. TNF alpha localization in neurons and its modification of NE release comparable to alpha 2-adrenergic receptor activation, explains a functional role for the cytokine as a neuromodulator in the CNS.

Twenty-four-hour rhythms of serum ACTH, prolactin, growth hormone, and thyroid-stimulating hormone, and of median-eminence norepinephrine, dopamine, and serotonin, in rats injected with Freund's adjuvant

The effect of Freund's adjuvant injection on 24-h variation of circulating ACTH, prolactin, growth hormone (GH), and thyroid-stimulating hormone (TSH) levels, and of norepinephrine (NE) content, and dopamine (DA) and serotonin (5HT) turnover in median eminence, was examined in adult rats kept under light between 0800 and 2000 h daily. Groups of 6-10 animals received Freund's complete adjuvant or its vehicle at 1100 h 3 days before sacrifice and were killed by decapitation at six different time intervals throughout a 24-h cycle. In rats injected with adjuvant's vehicle, serum ACTH and prolactin exhibited peak values around the light-dark transition (p < 0.0001 and < 0.04, respectively), while the maximum in TSH was found in the late afternoon (p < 0.0001, one-way ANOVA). GH levels did not vary on a 24-h basis. In Freund's adjuvant-injected rats, 24-h variations of TSH levels became blunted, while 24-h variations of prolactin and ACTH persisted. Freund's adjuvant augmented serum ACTH and prolactin levels, and decreased GH and TSH levels (p < 0.0007, factorial ANOVA). Median-eminence NE content, and turnover of DA, assessed by measuring dihydroxyphenylacetic acid, DOPAC/DA ratio, and of 5HT, assessed by measuring 5-hydroxyindoleacetic acid, HIAA/5HT ratio, varied on a 24-h basis in rats receiving adjuvant's vehicle (p < 0.02). Median-eminence NE content attained its maximum at 1600-2000 h, while maxima in DOPA/DA and HIAA/5HT ratios occurred at 0400 h. Injection with Freund's adjuvant reduced the amplitude of the daily variation of NE content, shifted the maximum of DOPAC/DA ratio toward the light-dark transition, and blunted the daily variation in HIAA/5HT ratio in median eminence. The administration at 1200 of the immunosuppressant drug cyclosporine (5 mg/kg, 5 days) restored the augmented ACTH and prolactin levels (p < 0.0001, factorial ANOVA) and depressed GH and TSH levels (p < 0.02) found in Freund's adjuvant-injected rats. Cyclosporine was also effective in restoring 24-h rhythmicity of serum ACTH and TSH, but not of prolactin, levels. Cyclosporine did not modify the effect of Freund's adjuvant on time-of-day changes of median-eminence NE content, but it was effective in counteracting the changes of DA and 5HT turnover found after immunization. The results are compatible with a significant effect of immune-mediated inflammatory response at an early phase after Freund's adjuvant injection on ACTH, GH, prolactin, and TSH release, which is partially sensitive to immunosuppression by cyclosporine.

Immunoregulatory properties of growth hormone and prolactin

Reciprocal communication between the neuroendocrine and immune systems is critical to the establishment of host homeostatic and defence mechanisms. The production and utilisation of common ligands and their receptors by cells of the immune and neuroendocrine systems constitutes a biochemical information circuit between and within the immune and neuroendocrine systems. Although the structures of the various signalling components appear to be similar in both systems, the regulation of their synthesis may be different. Growth hormone and prolactin have similar and marked influences on the function/activity of each of the major immune cell types, both in vitro and in vivo. The underlying molecular mechanisms are just beginning to be unravelled, and it is anticipated that further work in this rapidly developing field will establish abnormal pituitary and/or lymphocyte growth hormone and prolactin synthesis and function as a contributory factor to a number of pathologic situations, including leukaemia and autoimmunity.

Proopiomelanocortin production by epidermal cells: evidence for an immune neuroendocrine network in the epidermis

Proopiomelanocortin (POMC) is known to be synthesized in the pituitary gland and is subsequently cleaved by specific prohormone convertases into biologically active peptide hormones such as melanocyte stimulating hormones (MSH), adrenocorticotropin (ACTH) and endorphins (EP). Guanine nucleotide-binding protein (G-protein)-coupled receptors, which have only recently been discovered, are involved in the transmission of their message. There is also evidence indicating that POMC is not only produced by pituitary cells but is an ubiquitous molecule, that is cleaved cell- and tissue-specific. It has also been shown that the epidermis keratinocytes as well as melanocytes express POMC upon stimulation and release alpha MSH and ACTH. In addition to their function as hormones, POMC peptides have been shown to exert a variety of immunoregulatory effects by modulating the function of immunocompetent cells as well as cytokines. These findings provide further evidence for the immunoneuroendocrine network playing a crucial role during the pathogenesis of immune and inflammatory skin disease.

Pituitary and ovarian interleukin-1 alpha content changes according to estrous cycle and acute stress exposure

A complex interaction between the immune and neuroendocrine systems has been established. In particular, cytokines are known to be one of the mediators of the stress response, and modulate hormone secretion by acting in the brain, pituitary and gonads. The aim of the present study is to investigate whether pituitary and ovarian interleukin-1 alpha (IL-1 alpha) content changes according to the estrous cycle. In addition, the possible pituitary and ovarian IL-1 alpha changes in rats exposed to acute (5 min) or chronic intermittent (twice a day for 4 days) cold swimming stress were studied. The IL-1 alpha content of ovarian and pituitary homogenates was measured by a sensitive and specific radioimmunoassay. Immunoreactive IL-1 alpha (irIL-1 alpha) was detectable only in ovaries collected in rats at proestrus and estrus while not in those collected at diestrus I and II. The highest values were found at proestrus. No significant changes were found in ovarian irIL-1 alpha content in rats exposed to acute or chronic intermittent stress in comparison to control rats. In the pituitary, no difference in IL-1 alpha content was found throughout the estrous cycle. Acute stress induced a significant increase in pituitary irIL-1 alpha content only at proestrus (p < 0.01), however, no significant differences were found in comparison to control rats after chronic intermittent stress. The proestrus-related changes of ovarian IL-1 alpha may constitute a hormone-dependent signal within the ovary that is involved in the ovulatory process.(ABSTRACT TRUNCATED AT 250 WORDS)

Immunoendocrine mechanisms in mammary tumor progression: direct prolactin modulation of peripheral and preneoplastic hyperplastic-alveolar-nodule- infiltrating lymphocytes

We have previously shown that the immunoregulatory function of prolactin may play a role in the progression of the mouse mammary preneoplastic hyperplastic alveolar nodule (HAN) line C4 to carcinoma. In this study we investigated the direct effect of prolactin on lymphocytes isolated from normal and C4-HAN-bearing mice. In addition, we tested the effect of ovariectomy on prolactin/lymphocyte interaction to see whether, as has been reported in rats [Mukherjee P., Hymer W. C. (1992) Prog Neuroendocrinol Immunol 5: 108; Viselli S. M. et al. (1991) Endocrinology 129: 983], removal of estrogen would enhance the response to prolactin in mice. Proliferation of splenocytes, lymph node cells and HAN-infiltrating lymphocytes was stimulated by prolactin in a dose-responsive fashion. Ovariectomy did not alter this effect consistently. Cell-cycle analysis based on simultaneous staining of DNA and RNA revealed that prolactin-stimulated lymphocytes progress through all phases of the cell cycle whereas anti-prolactin antiserum inhibits this stimulation. Two-color flow-cytometric analysis revealed the time-dependent induction of interleukin-2 (IL-2) receptor expression on both CD4+ and CD8+ cells by prolactin. Prolactin-treated lymphocytes also produced low yet detectable levels of bioactive IL-2 in a dose- and time-dependent fashion. Prolactin enhanced lymphocyte responsiveness to mitogens and showed a marked synergism at suboptimal concentrations. Pretreatment of splenocytes from HAN bearers with a high concentration of prolactin slightly enhanced natural killer (NK) activity; anti-prolactin antiserum reduced the NK lytic activity of poly(I).poly(C)-activated splenocytes from HAN-bearing mice. Our results provide direct experimental evidence for the stimulatory effect of prolactin on lymphocyte function and IL-2-mediated lymphocyte proliferation and suggest a mechanism linking the endocrine system to immunomediated enhancement of HAN progression.

Increased interleukin-2 levels during standard TRH test in man

Interleukin-2 (IL-2) is a pluripotential cytokine that, besides its role in the regulation of immunocompetent cells function, also stimulates hormone secretion. On the other hand, several factors, including cytokines (interleukin-1, IL-1; interleukin-6, IL-6) and pituitary hormones (thyrotropin, TSH; prolactin, PRL), exert stimulatory effects on T-cell connected IL-2 production. In order to evaluate the role of both pituitary hormones in the activation of the immune system, the following two standard diagnostic tests were performed: TRH test (0.2 mg) in 8 healthy human subjects (4F/4M) aged 18-50 years, and oral metoclopramide (MCP) test (10 mg) in 8 females with galactorrhea and regular menstruation aged 18-52 years. The mobilization (peak response) of PRL, TSH, triiodothyronine (T3), thyroxin (T4), IL-1 beta, IL-2, IL-6 in TRH test, and PRL, IL-1 beta, IL-2, IL-6 for MCP test were evaluated. The responses of TSH (2.0 +/- 0.3 vs 12.3 +/- 2.2 microlU/ml, p < 0.01), PRL (15.3 +/- 2.3 vs 46.4 +/- 8.8 ng/ml, p < 0.01), T3 (178.0 +/- 16.4 vs 248.7 +/- 21.1 ng/dl, p < 0.001), T4 (7.9 +/- 0.4 vs 9.6 +/- 0.5 micrograms/dl, p < 0.001), and IL-2 (45.6 +/- 7.8 vs 79.9 +/- 16.4 fmol/ml, p < 0.05) in TRH test were noted. The peak response of PRL (16.3 +2- 2.6 vs 107.7 +/- 22.4 ng/ml, p < 0.01) in MCP test was also observed, but without any changes in interleukin concentrations.(ABSTRACT TRUNCATED AT 250 WORDS)

Eicosanoids and essential fatty acid modulation in chronic disease and the chronic fatigue syndrome

Abnormalities of Essential Fatty Acid (EFA) incorporation into phospholipid are found in chronic diseases. More recently changes in circulating EFA metabolites (EFAM) together with EFAM hypo-responsiveness of immune cells and EFAM production from cells have been found associated with disease. We hypothesize that changes in ratio of EFAMs are the normal physiological responses to stressors, but when stressors are excessive or prolonged, EFAM systems may become unpredictably hypo-responsive owing to factors such as receptor down regulation and substrate depletion. In time, many homeostatic system become deranged and held in that state by minor stressors. Literature review of chronic fatigue syndrome (CFS) shows hyper and hypo-responsiveness in immune function, several Hypothalamo-Pituitary (HP) axes and sympathetic nervous system, all relatable to dysfunctional changes in EFA metabolism. For the first time, we explain chronic immune system activation and hypo-responsive immune function in CFS; through EFAMs. Dietary EFA modulation (DEFA) can alter ratios of both membrane EFAs and produced EFAMs, and if maintained can restore hypo-responsive function. We discuss dietary strategies and relevance in CFS, and a case series of CFS patients applying DEFA with other titrated published managements which saw 90% gaining improvement within 3 months and more than 2/3 fit for full time duties. This hypothesis and DEFA may have relevance in other chronic conditions.

Cytokines, glucocorticoids and neuroendocrine function

Activation of the immune system is normally associated with widespread alterations in neuroendocrine activity, the profile of which depends upon the species and on the severity and duration of the stimulus. Particularly important in this regard is the activation of the hypothalamo-pituitary-adrenocortical (HPA) axis for the consequent rise in circulating glucocorticoids serves to contain the ensuing pathophysiological responses and thus to restore homeostasis. In the present study, in vivo and in vitro techniques have been used to examine the influence of various immunokines on the HPA axis and to determine whether their actions are modulated by glucocorticoids and lipocortin 1 (LC1). In vivo interleukin-1 beta (IL-1 beta), given orally or peripherally, produced increases (P < 0.01) the serum corticosterone concentration which were reversed by pretreatment with dexamethasone. IL-1 beta also produced glucocorticoid reversible increases in the release of the two corticotrophin releasing factors, CRF-41 and AVP, from the hypothalamus in vitro (P < 0.01) as also did IL-1 alpha, IL-6 and IL-8. By contrast, none of these cytokines influenced directly the release of ACTH from pituitary tissue in vitro. The inhibitory actions of the glucocorticoids on the HPA responses to cytokines observed in vivo and in vitro were mimicked by LC1 and reversed by neutralizing anti-LC1 antisera. Our results demonstrate a role of cytokines, glucocorticoids and LC1 in effecting the interplay between the brain-neuroendocrine and immune system which may be critical to host defence in conditions of both health and disease.

Endocrine considerations in toxicologic pathology

Detection of xenobiotic-induced toxicity on the endocrine system is a very difficult task because of the close relationship that the endocrine system has with the neural and immune systems. This is further complicated when one is asked to extrapolate from lab animals to man. Knowledge across species of hormonal action, solubility, transportation, plasma half life, receptor location, type of mediator, rhythmicity and pattern of secretion, is essential. One hormone can exert various effects in different tissues, or one function can be regulated by several hormones or even many functions of one endocrine target tissue can be regulated by several hormones acting in concert. The endocrine toxic response is determined by the state of differentiation of the target site. Feedback mechanisms both positive and negative, should also be taken into consideration initially. Because the effects of hormones have wide-ranged ramifications, the toxic responses likewise encompass broad areas such as the regulation of energy availability, maintenance of the internal environmental, development, growth and reproduction. The initial step involves the ascertaining of interference with the general trophic and target gland function and the characterization of the primary toxic effect. Equally important is to calculate the dose which elicited this primary effect, taking into consideration the area under the curve of the target endocrine site. Adapting this step-by-step approach, the causality between a specific toxic dose and a specific toxic effect can be readily and reliably established across all lab animal species and man.

Distribution and characterization of tumor necrosis factor-alpha-like immunoreactivity in the murine central nervous system

Tumor necrosis factor-alpha (TNF alpha) is a protein released from macrophages during infection and inflammation. Recent studies suggest that it has several effects within the central nervous system, including generation of fever, enhancement of slow wave sleep, and stimulation of pituitary hormone secretion. We have proposed that TNF alpha may be synthesized by neurons in the CNS and used as a neuromodulator in the pathways involved in the central control of these activities. To test this hypothesis, we have used an antiserum raised against recombinant murine (rm) TNF alpha with an indirect immunoperoxidase technique to stain the murine CNS immunohistochemically. Western blot analysis of mouse brain homogenates revealed one band with electrophoretic mobility identical to that of rmTNF alpha. We identified TNF alpha-like immunoreactive (ir) neurons in the hypothalamus, in the bed nucleus of the stria terminalis, in the caudal raphe nuclei, and along the ventral pontine and medullary surface. TNF alpha ir innervation was widespread within the CNS, particularly in areas involved in autonomic and endocrine regulation, including the hypothalamus, amygdala, bed nucleus of the stria terminalis, parabrachial nucleus, dorsal vagal complex, nucleus ambiguus, and thoracic sympathetic preganglionic cell column. Our data suggest that TNF alpha may serve as a neuromodulator in central pathways involved in the regulation of the autonomic, endocrine and behavioral components of the acute-phase response to inflammation and infection.

Neuroendocrine regulation of thyrotropin-releasing hormone (TRH) in the tuberoinfundibular system

[...] It is now required to list each part needed for mucous excretion. They are two ducts in the brain substance, then a thin portion of membrane shaped as the infundibulum, then the gland that receives the tip of this infundibulum and the ducts that drive the mucus (pituita) from this gland to the palate and nares. [...] and I said that one (duct) [...] from the middle of the common cavity (third ventricle) descends [...] into the brain substance, and the end of this duct is [...] the sinus of the gland where the brain mucus is collected [...].

Murine tumor necrosis factor alpha is transported from blood to brain in the mouse

The cytokines are important components of the brain-immune axis. Recent work has shown that [125I]IL-1 alpha and [125I]IL-1 beta are transported from the blood into the brain by a saturable system. Here we show that murine tumor necrosis factor alpha (mTNF alpha) labeled with 125I (I-mTNF alpha) crosses the blood-brain barrier (BBB) after i.v. injection by a transport system different from that for the interleukins. Self inhibition with mTNF alpha showed that this transport system was saturable, and lack of inhibition by IL-1 alpha, IL-1 beta, IL-6, or MIP-1 alpha showed selectivity of the system. High performance liquid chromatography (HPLC) of the radioactivity recovered from brain and from cerebrospinal fluid after the i.v. injection of I-mTNF alpha showed that the cytokine crossed the BBB largely in intact form. Capillary depletion showed that the accumulation of I-mTNF alpha in the cerebral cortex was due to passage across the BBB rather than to sequestration by capillaries. Transport rate was not changed by acute treatment with the neurotoxin aluminium or by acute and chronic treatment with the cationic chelator deferoxamine, but it was more than three times faster in neonatal rats. Efflux of I-mTNF alpha from the brain was slower than would have been predicted based on reabsorption of cerebrospinal fluid, suggesting that TNF alpha is sequestered by the brain. The BBB was not disrupted by up to 50 micrograms kg-1 of mTNF alpha i.v. in either adult mice or neonatal rats as assessed by the BBB's impermeability to radioactively labeled albumin.(ABSTRACT TRUNCATED AT 250 WORDS)

Psychomotor retardation, anorexia, weight loss, sleep disturbances, and loss of energy: psychopathological correlates of hyperhaptoglobinemia during major depression

Recently, we have established that major depression is characterized by hyperhaptoglobinemia, which may be regarded as an index of an "acute" phase response in that illness. The present study investigates the psychopathological correlates of increased plasma concentrations of haptoglobin (Hp) in major depression. To this end, the authors studied the Hp levels in relation to depressive items of the Structured Clinical Interview for DSM-III (SCID) and the Hamilton Rating Scale for Depression (HRSD) in 90 depressed subjects. There was a significant positive relationship between the SCID symptoms anorexia/weight loss, sleep, and psychomotor disorders and Hp plasma concentrations. Hp plasma levels were significantly and positively correlated with overall severity of illness (HRSD). The HRSD symptom correlates of higher Hp levels were loss of interest, middle insomnia, and psychomotor retardation. Up to 31.4% of the variance in Hp plasma values could be explained by psychomotor disorders, anorexia, weight loss, middle insomnia, and less diurnal variation of mood. It is suggested that hyperhaptoglobinemia, as an index of an "acute" phase response in major depression, is related to the somatic dimension of depressive illness.

Psychopathology of pancreatic cancer. A psychobiologic probe

Reports of characteristic psychiatric symptoms occurring in patients with pancreatic cancer appear regularly in the literature. A review of this literature reveals that symptoms of depression and/or anxiety may appear in approximately 50% of patients with pancreatic cancer before the diagnosis is made. This review proposes that the psychopathology of pancreatic tumors may be linked to tumor-induced changes in neuroendocrine or acid-base systems. Although confirmatory data are lacking, informed speculation centers on the potential role of adrenocorticotropic hormone, parathyroid hormone, thyrotropin-releasing hormone, glucagon, serotonin, insulin, and bicarbonate in the production of depression and/or anxiety in this disease. Elucidation of the pathophysiology of the psychiatric symptoms in patients with pancreatic cancer may provide a marker for early diagnosis of pancreatic neoplasia as well as a probe into the biologic bases of depression and anxiety.

Release of corticotropin-releasing factor from superfused rat hypothalami induced by interleukin-1 is not dependent on adrenergic mechanism

Interleukin-1 (IL-1) is a potent activator of the hypothalamic-pituitary-adrenal (HPA) axis. The hypothalamus seems to be the most important site of action of IL-1 on the HPA axis, inducing corticotropin-releasing factor (CRF) secretion. Catecholamines are important modulators of CRF secretion. In turn, IL-1 stimulates catecholamine release from the hypothalamus. In the present study, we examined the possible involvement of hypothalamic catecholamines in the effect of IL-1 beta on hypothalamic CRF secretion, by using an in vitro rat hypothalami continuous perifusion system. Neither in vivo pretreatment with an inhibitor of catecholamine synthesis nor in vitro exposure to alpha- or beta-adrenoceptor antagonists (phenoxybenzamine or propranolol, respectively) nor combination of both treatments altered the effect of IL-1 on CRF secretion from superfused hypothalami. These data indicate that catecholamines are not involved in the in vitro stimulatory action of IL-1 on hypothalamic CRF secretion.

In vivo administration of recombinant growth hormone or gamma interferon activities macrophages: enhanced resistance to experimental Salmonella typhimurium infection is correlated with generation of reactive oxygen intermediates

Purified and recombinant forms of growth hormone (GH) as well as of recombinant rat gamma interferon (IFN-gamma) enhance the survival of rats deprived of endogenous pituitary GH secretion by hypophysectomy (HX rats) and infected with virulent Salmonella typhimurium. Macrophages obtained from rats with intact pituitaries (pituitary-intact rats) or HX rats that were treated in vivo with either GH or the closely related hormone prolactin released elevated (P less than 0.05) levels of superoxide anion (O2-) after in vitro opsonized-zymosan stimulation compared with those from placebo-treated animals. These levels of O2- release were similar in magnitude to those of macrophages from rats treated in vivo with IFN-gamma. In time course in vivo macrophage activation studies, both IFN-gamma and GH significantly increased O2- secretion within 24 h, with maximal secretion occurring at day 3. Macrophages obtained from pituitary-intact and HX rats injected in vivo with GH also released elevated (P less than 0.05) levels of hydrogen peroxide (H2O2) and displayed enhanced (P less than 0.01) phagocytic activity toward opsonized Listeria monocytogenes in vitro. The mechanism of action of GH in vivo is likely to be a direct one because resident peritoneal macrophages from rats could be primed in vitro for enhanced secretion of O2- following triggering of these cells with opsonized zymosan. These data show that in vivo administration of two closely related pituitary hormones, GH and prolactin, can effectively prime macrophages, which is consistent with the hypothesis that GH mediates resistance to S. typhimurium by a direct stimulatory action on macrophages.

Tumor necrosis factor modulates the inactivation of catecholamine secretion in cultured sympathetic neurons

Cytokines exert multiple effects on cellular functions. We studied the effects of cytokines on the calcium-dependent release of catecholamines in cultured neurons from neonatal rat superior cervical ganglia. Incubation of sympathetic neurons with recombinant human interleukin-1 beta (0.14-0.7 nM) or recombinant human tumor necrosis factor-alpha (1 nM) for 24-48 h had no effect on the baseline spontaneous release and the initial K(+)-evoked [3H]norepinephrine release, compared with untreated cells. A repeat K(+)-induced depolarization after 6 min resulted in a decrease of [3H]norepinephrine secretion to 69 +/- 5.8% (n = 11) of the initial secretion in recombinant human tumor necrosis factor-treated cells, but not in control cells. The secretory response was restored when the interval between the two K+ challenges was increased to 10 min. We conclude that the diminished secretory response to a repeat stimulus in recombinant human tumor necrosis factor-treated superior cervical ganglia neurons is due to a prolonged recovery from inactivation of secretion in these cells.

Immunoregulators in the nervous system

The nervous system, through the production of neuroregulators (neurotransmitters, neuromodulators and neuropeptides) can regulate specific immune system functions, while the immune system, through the production of immunoregulators (immunomodulators and immunopeptides) can regulate specific nervous system functions. This indicates a reciprocal communication between the nervous and immune systems. The presence of immunoregulators in the brain and cerebrospinal fluid is the result of local synthesis--by intrinsic and blood-derived macrophages, activated T-lymphocytes that cross the blood-brain barrier, endothelial cells of the cerebrovasculature, microglia, astrocytes, and neuronal components--and/or uptake from the peripheral blood through the blood-brain barrier (in specific cases) and circumventricular organs. Acute and chronic pathological processes (infection, inflammation, immunological reactions, malignancy, necrosis) stimulate the synthesis and release of immunoregulators in various cell systems. These immunoregulators have pivotal roles in the coordination of the host defense mechanisms and repair, and induce a series of immunological, endocrinological, metabolical and neurological responses. This review summarizes studies concerning immunoregulators--such as interleukins, tumor necrosis factor, interferons, transforming growth factors, thymic peptides, tuftsin, platelet activating factor, neuro-immunoregulators--in the nervous system. It also describes the monitoring of immunoregulators by the central nervous system (CNS) as part of the regulatory factors that induce neurological manifestations (e.g., fever, somnolence, appetite suppression, neuroendocrine alterations) frequently accompanying acute and chronic pathological processes.

Bovine sarcocystosis: How parasites negatively affect growth

Growth, though genetically encoded, is markedly influenced in healthy animals by the interaction of hormonal and nutritional factors. The uptake and use of nutrients by specific tissues is regulated by a priority system that modulates physiological processes. Nutritional, hormonal and immunological consequences of parasitism often lead to partitioning of nutrients away from growth. In this article, Ron Foyer and Ted Elsosser use a bovine sarcocystosis model to show that changes in plasma concentrations of insulin-like growth factor-I (IGF-I), growth hormone (GH) and somotostotin (SSN), as well as the host's immunological response to the parasite via cytokine interactions with the endocrine system, are modulators of perturbed growth.