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Hormone Responses (hormone + response)
Kinds of Hormone Responses Selected AbstractsHormone Responses to Social Stress in Abstinent Alcohol-Dependent Subjects and Social Drinkers with No History of Alcohol DependenceALCOHOLISM, Issue 7 2005Cynthia A. Munro Background: Previous studies have described blunted stress hormone responses after pharmacological activation of the hypothalamic-pituitary-adrenal (HPA) axis in sober alcoholics. The aim of the present study was to compare ACTH, cortisol, and prolactin responses to a psychological stressor in abstinent alcohol-dependent subjects matched to healthy control subjects. Methods: Individuals who met DSM-IV diagnostic criteria for a history of alcohol dependence but not for other axis I disorders were included in the study (n= 18; mean duration of abstinence ± SEM, 3.5 ± 5.7 years). Social drinkers (n= 23) served as control subjects. The sober alcohol-dependent and control subjects were matched for demographic measures including levels of stress symptoms. All subjects underwent the Trier Social Stress Test (TSST), a laboratory-based psychological stressor. Prestress and poststress plasma ACTH, cortisol, and prolactin levels, as well as a self-report measure of anxiety (State-Trait Anxiety Inventory), were obtained. Results: Nondepressed, abstinent alcoholics and control subjects did not differ with regard to age, racial composition, or baseline or poststress ratings of anxiety. Whereas ACTH and cortisol levels increased in response to the TSST, prolactin levels did not. Stress hormone response curves for the three hormones did not differ between the alcoholics and control subjects. Conclusions: When matched for levels of stress, a laboratory-based psychological stress test did not induce differential hormone response curves for abstinent alcoholics and control subjects. [source] Hormone response to bidirectional selection on social behaviorEVOLUTION AND DEVELOPMENT, Issue 5 2010Gro V. Amdam SUMMARY Behavior is a quantitative trait determined by multiple genes. Some of these genes may have effects from early development and onward by influencing hormonal systems that are active during different life-stages leading to complex associations, or suites, of traits. Honey bees (Apis mellifera) have been used extensively in experiments on the genetic and hormonal control of complex social behavior, but the relationships between their early developmental processes and adult behavioral variation are not well understood. Bidirectional selective breeding on social food-storage behavior produced two honey bee strains, each with several sublines, that differ in an associated suite of anatomical, physiological, and behavioral traits found in unselected wild type bees. Using these genotypes, we document strain-specific changes during larval, pupal, and early adult life-stages for the central insect hormones juvenile hormone (JH) and ecdysteroids. Strain differences correlate with variation in female reproductive anatomy (ovary size), which can be influenced by JH during development, and with secretion rates of ecdysteroid from the ovaries of adults. Ovary size was previously assigned to the suite of traits of honey bee food-storage behavior. Our findings support that bidirectional selection on honey bee social behavior acted on pleiotropic gene networks. These networks may bias a bee's adult phenotype by endocrine effects on early developmental processes that regulate variation in reproductive traits. [source] Exercise-induced growth hormone response in euglycaemia and hyperglycaemia in patients with Type 1 diabetes mellitusDIABETIC MEDICINE, Issue 2 2010S. Jenni Diabet. Med. 27, 230,233 (2010) Abstract Aims, To compare exercise-induced growth hormone (GH) response in patients with Type 1 diabetes during stable euglycaemic and hyperglycaemic conditions. Methods, We conducted a randomized, controlled, single-blinded cross-over trial in seven male patients with well-controlled Type 1 diabetes. The patients cycled twice for 120 min at a level of 55,60% maximal oxygen uptake. Euglycaemia was at 5.0 mmol/l, hyperglycaemia at 11.0 mmol/l. Results, Area under the curve of GH (AUCGH) during exercise was significantly higher during euglycaemia [1430 ng ml,1 min, 95% confidence interval (CI) 703,2910] compared with hyperglycaemia (1061 ng ml,1 min, 95% CI 538,2091, P = 0.02). Conclusions, In patients with Type 1 diabetes, GH concentrations during moderate aerobic exercise during stable hyperglycaemic conditions are significantly lower compared with euglycaemia. These findings are compatible with preserved glucose-mediated GH regulation during exercise in individuals with well-controlled Type 1 diabetes. [source] Diurnal rhythms in neurohypophysial functionEXPERIMENTAL PHYSIOLOGY, Issue 2000Mary L. Forsling The neurohypophysial hormones oxytocin and vasopressin show daily rhythms of secretion with elevated hormone release during the hours of sleep. This pattern can be modulated by ovarian steroids and alters with age. The pattern appears to be due in part to the nocturnal increase in melatonin secretion, which stimulates hormone release in man, while being inhibitory in the rat. Pinealectomy alters both the 24 h pattern of neurohypophysial hormone release in the rat and the firing rate of magnocellular supraoptic nucleus neurones. There is also a reduced hormone release in response to hypovolaemia and raised plasma sodium concentration compared to sham operated animals, with a smaller increase in neuronal activity, as determined by immediate-early gene expression. The normal responses can be restored by nocturnal administration of melatonin. Melatonin also influences the neurohypophysial hormone response in the human to known stimuli of release, such as raised plasma osmolality, exercise and insulin-induced hypoglycaemia. Recent studies have revealed that not only does the release of vasopressin and oxytocin vary over each 24 h, but the respective renal and pregnant uterine responses also show diurnal variations. [source] Sumatriptan challenge in bipolar patients with and without migraine: a neuroendocrine study of 5-HT1D receptor function.HEADACHE, Issue 3 2003T Mahmood Int Clin Psychopharmacol. 2002 Jan;17(1):33-36 An association between bipolar disorder and migraine has been lately recognized and an abnormality of central serotonergic function is suggested as the underlying neurophysiological disturbance. To examine the role of serotonin in bipolar disorder and migraine, we used the neuroendocrine challenge paradigm, and we chose sumatriptan, a 5HT1D agonist, as the pharmacological probe. We studied nine bipolar patients with migraine, nine bipolar patients without it, seven migraine patients, and nine matched normal controls. A post-hoc analysis showed subsensitivity of serotonergic function, reflected in a blunted growth hormone response to sumatriptan challenge in bipolar patients who also suffered from migraine. Comment: Given regulatory and labelling concerns about the potential for triptans to provoke serotonin syndrome, the apparent down-regulation of serotonergic function in patients with bipolar disorder may suggest cause for cautious optimism and encourage future study of triptans in these patients to establish true causality or otherwise. A prospective trial of sumatriptan injectable identified 1700 patients who repetitively used the triptan and were concomitantly on selective serotonin reuptake inhibitor (SSRI) medication. No serotonin syndrome was reported in any patient (Putnam GP, O'Quinn S, Bolden-Watson CP, Davis RL, Gutterman DL, Fox AW. Migraine polypharmacy and the tolerability of sumatriptan: a large-scale, prospective study. Cephalalgia. 1999;19:668-675). Since SSRIs can rarely induce serotonin syndrome alone, there is a significant difficulty in establishing a risk of coadministration. DSM and SJT [source] Stress Hormone Dysregulation at Rest and After Serotonergic Stimulation Among Alcohol-Dependent Men With Extended Abstinence and ControlsALCOHOLISM, Issue 5 2001Robert M. Anthenelli Background: Alcohol dependence has been associated with long-lasting alterations in limbic-hypothalamic-pituitary-adrenal (LHPA) axis and serotonin (5-hydroxytryptamine [5-HT]) function. Other conditions that are associated with alcoholism (cigarette smoking and antisocial personality disorder [ASPD]) have been linked with disturbances in these interrelated systems. We evaluated the stress hormone response to 5-HTergic stimulation in alcohol-dependent men with extended abstinence (average abstinence duration, 4.3 months) and controls to determine the relative contributions of alcoholism, cigarette smoking, and ASPD on baseline and provoked plasma cortisol and adrenocorticotropin hormone (ACTH) concentrations. Methods: One hundred nine alcohol-abstinent men with alcohol dependence (62%), habitual smoking (70%), and ASPD (43%) received d,l-fenfluramine (100 mg po) in a randomized, double-blind, placebo-controlled, crossover trial. The group of recovering alcohol-dependent individuals included abstinent primary alcohol-dependent men and alcohol-dependent men with ASPD, whereas the group of non-alcohol-dependent men comprised healthy controls and non-alcohol-dependent men with ASPD. Plasma cortisol and ACTH levels were obtained at AM baseline and at half-hour intervals after drug administration. Subjective ratings of drug response and physiological measures were also obtained at baseline and every 30 min. Results: Abstinent alcohol-dependent men had significantly lower (approximately 20%) AM baseline plasma cortisol concentrations than non-alcohol-dependent men on both challenge days; however, no differences between the groups were observed with regard to resting AM plasma ACTH levels. After adjusting for these baseline differences, recovering alcohol-dependent men (area under curve = 35.6 ± 37.4 [,g/dl] × min) had a twofold greater cortisol response to fenfluramine than non-alcohol-dependent men (area under curve = 17.5 ± 32.5 [,g/dl] × min) (F= 5.1;df= 1,105;p < 0.03). The elevated cortisol response, which occurred primarily along the descending limb of the response curve, was paralleled by a nonsignificant statistical trend for alcohol-dependent men to also exhibit a greater ACTH response to fenfluramine at the 210-min (p < 0.07) and 240-min (p < 0.09) time points as compared with non-alcohol-dependent men. Cigarette smoking and ASPD did not affect hormonal responses, nor could the groups' subjective ratings and physiological measures be distinguished. Conclusions: Alcohol-dependent men with extended abstinence differed from age- and race-matched non-alcohol-dependent men in resting AM and fenfluramine-induced plasma cortisol levels. This dysfunction in glucocorticoid homeostatic mechanisms was associated with alcoholism and not with smoking or ASPD. We also observed a nonsignificant statistical trend for plasma ACTH levels to be elevated among alcohol-dependent men along the descending limb of the response curve. Alcohol-dependent men seemed to have inherited or acquired damage to 5-HT-regulated LHPA axis function, the precise mechanisms and sites of which remain to be determined. [source] Comparing hormonal and symptomatic responses to experimental hypoglycaemia in insulin- and sulphonylurea-treated Type 2 diabetesDIABETIC MEDICINE, Issue 7 2009P. Choudhary Abstract Aims, Patients with diabetes rely on symptoms to identify hypoglycaemia. Previous data suggest patients with Type 2 diabetes develop greater symptomatic and hormonal responses to hypoglycaemia at higher glucose concentrations than non-diabetic controls and these responses are lowered by insulin treatment. It is unclear if this is as a result of insulin therapy itself or improved glucose control. We compared physiological responses to hypoglycaemia in patients with Type 2 diabetes patients treated with sulphonylureas (SUs) or insulin (INS) with non-diabetic controls (CON). Methods, Stepped hyperinsulinaemic hypoglycaemic clamps were performed on 20 subjects with Type 2 diabetes, 10 SU-treated and 10 treated with twice-daily premixed insulin, and 10 age- and weight-matched non-diabetic controls. Diabetic subjects were matched for diabetes duration, glycated haemoglobin (HbA1c) and hypoglycaemia experience. We measured symptoms, counterregulatory hormones and cognitive function at glucose plateaux of 5, 4, 3.5, 3 and 2.5 mmol/l. Results, Symptomatic responses to hypoglycaemia occurred at higher blood glucose concentrations in SU-treated than INS-treated patients [3.5 (0.4) vs. 2.6 (0.5) mmol/l SU vs. INS; P = 0.001] or controls [SU vs. CON 3.5 (0.4) vs. 3.0 (0.6) mmol/l; P = 0.05]. They also had a greater increase in symptom scores at hypoglycaemia [13.6 (11.3) vs. 3.6 (6.1) vs. 5.1 (4.3) SU vs. INS vs. CON; P = 0.017]. There were no significant differences in counterregulatory hormone responses or impairment of cognitive function among groups. Conclusions, Sulphonylurea-treated subjects are more symptomatic of hypoglycaemia at a higher glucose level than insulin-treated subjects. This may protect them from severe hypoglycaemia but hinder attainment of glycaemic goals. [source] Thyroid hormone responses to endurance exerciseEQUINE VETERINARY JOURNAL, Issue S36 2006E. A. GRAVES Summary Reasons for performing study: Limited information exists about changes in circulating thyroid hormone concentrations during prolonged endurance exercise in horses. Objective: To examine the effects of prolonged exercise on serum iodothyronine concentrations in horses performing endurance exercise of varying distances. Methods: Serum concentrations of iodothyronines were measured in horses before and after completion of 40, 56, 80 and 160 km endurance rides (Study 1); daily during a 5 day, 424 km endurance ride (Study 2); and before and for 72 h after completion of a treadmill exercise test simulating a 60 km endurance ride (Study 3). Results: In Study 1, 40 and 56 km of endurance exercise had little effect on serum iodothyronine concentrations with the exception of a 10% decrease (P<0.05) in free thyroxine (FT4) concentration after the 56 km ride. In contrast, total thyroxine (T4), total triiodothyronine (T3), FT4 and free triiodothyronine (FT3) concentrations all decreased (P<0.05) after successful completion of 80 and 160 km rides, with decreases ranging from 13,31% and 47,54% for distances of 80 and 160 km, respectively. Further, pre-ride T4 concentration was lower (P<0.05) and FT3 concentration was higher (P<0.05) in horses competing 160 km as compared to horses competing over shorter distances. In Study 2, serum concentrations of T4, T3 and reverse triiodothyronine (rT3) progressively decreased (P<0.05) over the course of the multi-day ride. In Study 3, the greatest decrease (P<0.05) in all iodothyronines was observed at 12 h of recovery, ranging from 25% for FT4 to 53% for FT3, but all thyroid hormone concentrations had returned to the pre-exercise values by 24 h of recovery. Conclusion: Endurance exercise results in transient decreases in serum iodothyronine concentrations. Potential relevance: These data are important to consider when thyroid gland function is assessed by measurement of serum iodothyronine concentrations in endurance horses. [source] CDP-choline increases plasma ACTH and potentiates the stimulated release of GH, TSH and LH: the cholinergic involvementFUNDAMENTAL & CLINICAL PHARMACOLOGY, Issue 5 2004Sinan Cavun Abstract In the present study, we investigated the effect of intracerebroventricular (i.c.v.) administration of cytidine-5,-diphosphate (CDP) choline on plasma adrenocorticotropin (ACTH), serum growth hormone (GH), thyroid stimulating hormone (TSH), follicle stimulating hormone (FSH) and luteinizing hormone (LH) levels in conscious rats. The involvement of cholinergic mechanisms in these effects was also determined. In basal conditions, CDP-choline (0.5, 1.0 and 2.0 ,mol, i.c.v.) increased plasma ACTH levels dose- and time-dependently, but it did not affect the TSH, GH, FSH and LH levels. In stimulated conditions, i.c.v. administration of CDP-choline (1 ,mol, i.c.v.) produced an increase in clonidine-stimulated GH, thyrotyropin-releasing hormone (TRH)-stimulated TSH, LH-releasing hormone (LHRH)-stimulated LH, but not FSH levels. Injection of equimolar dose of choline (1 ,mol, i.c.v.) produced similar effects on hormone levels, but cytidine (1 ,mol, i.c.v.) failed to alter plasma levels of these hormones. Pretreatment with hemicholinium-3, a neuronal high affinity choline uptake inhibitor, (20 ,g, i.c.v.) completely blocked the observed hormone responses to CDP-choline. The increase in plasma ACTH levels induced by CDP-choline (1 ,mol, i.c.v.) was abolished by pretreatment with mecamylamine, a nicotinic receptor antagonist, (50 ,g, i.c.v.) but not atropine, a muscarinic receptor antagonist, (10 ,g, i.c.v.). The increase in stimulated levels of serum TSH by CDP-choline (1 ,mol, i.c.v.) was blocked by atropine but not by mecamylamine pretreatment. However, CDP-choline induced increases in serum GH and LH levels were greatly attenuated by both atropine and mecamylamine pretreatments. The results show that CDP-choline can increase plasma ACTH and produce additional increases in serum levels of TSH, GH and LH stimulated by TRH, clonidine and LHRH, respectively. The activation of central cholinergic system, mainly through the presynaptic mechanisms, was involved in these effects. Central nicotinic receptors solely mediated the increase in plasma ACTH levels while the activation of central muscarinic receptors was involved in the increase in TSH levels. Both muscarinic and nicotinic receptor activations, separately, mediated the increases in serum GH and LH levels after CDP-choline. [source] Anaesthetic requirement and stress hormone responses in patients undergoing lumbar spine surgery: anterior vs. posterior approachACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 8 2009K. Y. YOO Background: The intensity of nociceptive stimuli reflects the severity of tissue injury. The anaesthetic requirement and stress hormonal responses were determined to learn whether they differ according to different surgical approaches (anterior vs. posterior) during the spinal surgery. Methods: Patients undergoing lumbar spine surgery without neurological deficits were divided into two groups: one having posterior (n=13) and the other having anterior fusion (n=13). The end-tidal sevoflurane concentrations (ETSEVO) required to maintain the bispectral index score at 40,50 were determined. Mean arterial pressure (MAP), heart rate (HR), central venous pressure (CVP), serum osmolality and plasma concentrations of catecholamines, cortisol and vasopressin (AVP) were measured. Results: There were no differences in MAP, HR, CVP and serum osmolality between the groups. ETSEVO was higher in the anterior than in the posterior group (P<0.05). The plasma concentrations of norepinephrine and cortisol increased in both groups during the surgery, whereas those of epinephrine remained unchanged. AVP concentrations increased during the surgery in the anterior group, and remained unaltered in the posterior group. The anterior group needed more analgesics (P<0.01) during the first 1 h after the operation. Conclusions: The anterior approach required a deeper level of anaesthesia while undergoing spinal surgery and more use of post-operative analgesics than the posterior approach. It was also associated with a more pronounced AVP release during the surgery. [source] Effects of Chronic Oestrogen Replacement on Stress-Induced Activation of Hypothalamic-Pituitary-Adrenal Axis Control PathwaysJOURNAL OF NEUROENDOCRINOLOGY, Issue 8 2000C. V. Dayas Abstract Oestrogen replacement therapy reportedly suppresses hypothalamic-pituitary-adrenal (HPA) axis responses to an emotional stressor in postmenopausal women. However, most studies in the rat suggest a facilitatory role for oestrogen in the control of HPA axis function. One explanation for this difference may be the regimen of oestrogen replacement: during oestrogen replacement therapy, oestrogen levels are low and constant whereas most animal studies examined the HPA axis response when oestrogen levels are rising. In the present study, we assessed HPA axis stress responses in mature ovariectomized rats after plasma oestrogen levels had been maintained at physiological levels for a prolonged period (25 or 100 pg/ml for 7 days). In the case of both an emotional stressor (noise) and a physical stressor (immune challenge by systemic interleukin-1, administration), oestrogen replacement suppressed stress-related Fos-like immunolabelling, in hypothalamic neuroendocrine cells and plasma adrenocorticotropin hormone responses. From the present data, and past reports, it appears unlikely that these effects of oestrogen are due to a direct action on corticotropin-releasing factor or oxytocin cells. Therefore, to obtain some indication of oestrogen's possible site(s) of action, Fos-like immunolabelling was mapped in the amygdala and in brainstem catecholamine groups, which are neuronal populations demonstrating substantial evidence of involvement in the generation of HPA axis stress responses. In the amygdala, oestrogen replacement suppressed central nucleus responses to immune challenge, but not to noise. Amongst catecholamine cells, oestrogen replacement was more effective against responses to noise than immune challenge, suppressing A1 and A2 (noradrenergic) and C2 (adrenergic) responses to noise, but only A1 responses to immune challenge. These data suggest that, as in postmenopausal women on oestrogen replacement therapy, chronic low-level oestrogen replacement can suppress HPA axis stress responses in the rat. Moreover, oestrogen appears to exert effects at multiple sites within putative HPA axis control pathways, even though most of the relevant neuronal populations do not contain genomic receptors for this gonadal steroid and the pattern of oestrogen action differs for an emotional vs a physical stressor. [source] Hormone Responses to Social Stress in Abstinent Alcohol-Dependent Subjects and Social Drinkers with No History of Alcohol DependenceALCOHOLISM, Issue 7 2005Cynthia A. Munro Background: Previous studies have described blunted stress hormone responses after pharmacological activation of the hypothalamic-pituitary-adrenal (HPA) axis in sober alcoholics. The aim of the present study was to compare ACTH, cortisol, and prolactin responses to a psychological stressor in abstinent alcohol-dependent subjects matched to healthy control subjects. Methods: Individuals who met DSM-IV diagnostic criteria for a history of alcohol dependence but not for other axis I disorders were included in the study (n= 18; mean duration of abstinence ± SEM, 3.5 ± 5.7 years). Social drinkers (n= 23) served as control subjects. The sober alcohol-dependent and control subjects were matched for demographic measures including levels of stress symptoms. All subjects underwent the Trier Social Stress Test (TSST), a laboratory-based psychological stressor. Prestress and poststress plasma ACTH, cortisol, and prolactin levels, as well as a self-report measure of anxiety (State-Trait Anxiety Inventory), were obtained. Results: Nondepressed, abstinent alcoholics and control subjects did not differ with regard to age, racial composition, or baseline or poststress ratings of anxiety. Whereas ACTH and cortisol levels increased in response to the TSST, prolactin levels did not. Stress hormone response curves for the three hormones did not differ between the alcoholics and control subjects. Conclusions: When matched for levels of stress, a laboratory-based psychological stress test did not induce differential hormone response curves for abstinent alcoholics and control subjects. [source] Pituitary luteinizing hormone responses to single doses of exogenous GnRH in female social Cape ground squirrels exhibiting low reproductive skewJOURNAL OF ZOOLOGY, Issue 1 2007T. P. Jackson Abstract The Cape ground squirrel Xerus inauris is unusual among social mammals as it exhibits a low reproductive skew, being a facultative plural breeder with not all females breeding within a group. We investigated pituitary function to assess whether there was reproductive inhibition at the level of the pituitary and potentially the hypothalamus in breeding and non-breeding female Cape ground squirrels. We did so during the summer and winter periods by measuring luteinizing hormone (LH) responses to single doses of 2 g exogenous gonadotropin-releasing hormone (GnRH) and physiological saline administered to 42 females from 11 colonies. Basal LH concentrations of females increased in response to the GnRH challenge. Basal plasma LH concentrations were greater during winter, when most oestrus events are observed. However, we found no differences in plasma LH concentrations between breeding and non-breeding females. We showed that the anterior pituitary of non-breeding female ground squirrels is no less sensitive to exogenously administered GnRH than that of breeding females. We therefore concluded that the pituitary is no more active in breeding than non-breeding females. The lack of differentiation in response to GnRH suggests that either non-breeding females have ovaries that are less sensitive to LH or that they refrain from sexual activity with males through an alternative mechanism of self-restraint. [source] Effects of Body Condition and Protein Supplementation on LH Secretion and Luteal Function in SheepREPRODUCTION IN DOMESTIC ANIMALS, Issue 5 2007CA Meza-Herrera Contents In ruminants, nutrition is one of the exogenous inputs affecting reproductive function at different levels of the hypothalamic,hypophyseal,gonadal axis. However, the exact mechanisms or even the identification of the signalling metabolic compounds by which nutrition affects reproductive function still need further clarification. The role of static body condition (BC) and its interaction with a short-term protein supplementation (PL), on secretion of metabolic hormones [growth hormone (GH), insulin and insulin-like growth factor-1 (IGF-1)], as well as on secretion of LH and progesterone (P4) was evaluated in sheep. Twenty-four Rambouillet ewes divided into two groups, with lower (LBC) and higher body condition (HBC), were randomly assigned within BC to one of two PL levels: low (LPL, 24% of crude protein; 14 g/animal/day), and high (HPL, 44% of crude protein; 30 g/animal/day). The secretion of GH, insulin, IGF-1 and LH was evaluated on day 10 of the oestrous cycle; appearance and timing of oestrous behaviour were previously detected using rams. Progesterone secretion was evaluated on day 13 of the same cycle. No differences were found (p > 0.05) between PL groups on serum GH concentrations during the sampling period (overall mean of 4.0 ± 0.3 ng/ml), but a trend for lower values in HBC sheep was found (3.6 ± 0.4 vs 4.4 ± 0.4 ng/ml, p = 0.06). A BC effect was observed (p < 0.05) on serum IGF-1 level, with higher values in HBC sheep (p < 0.05). Neither BC nor PL affected (p > 0.05) secretion of LH and the number of corpora lutea, nor serum P4 and insulin concentrations. Results indicate a predominance of the static component of nutrition on sheep metabolic hormone responses, GH and IGF-1, with no effect of short-term PL on secretion of pituitary and ovarian hormones as well as luteal number and activity. [source] The neuro-cardio-endocrine response to acute subarachnoid haemorrhageCLINICAL ENDOCRINOLOGY, Issue 5 2002Eric A. Espiner Summary objective Whereas cardiac hormones increase after subarachnoid haemorrhage (SAH), and may contribute to sodium wastage and hyponatraemia, there is controversy concerning the relative roles of atrial natriuretic peptide (ANP) vs. brain natriuretic peptide (BNP) and the factors initiating their secretion. Noting previous work linking stress hormone responses with cardiac injury after SAH, we have studied responses in stress hormones, markers of cardiac injury and the temporal changes in ANP and BNP and related them to changes in sodium status post ictus and during recovery from acute SAH. design, patients, measurements Eighteen patients with verified SAH of variable severity were studied in a single unit for a 14-day period post ictus under controlled conditions of sodium and fluid intake. All received a standardized protocol of daily dexamethasone and nimodipine throughout the study. Severity was graded using criteria of Hess and Hunt at admission. Stress hormones (AVP, catecholamines and admission plasma cortisol), markers of cardiac injury (ECG and daily plasma troponin T) and cardiac hormones (ANP and BNP) were measured daily and related to severity, plasma sodium and renin,aldosterone activity. Hormone levels (ANP, BNP and endothelin) in cerebrospinal fluid (CSF) were also measured in nine patients. results Intense neurohormonal activation (AVP, cortisol and catecholamines) at admission was associated with increased levels of both plasma ANP and BNP whereas levels in CSF were unaffected. In individual patients plasma levels of ANP and BNP were strongly correlated (P < 0·001). Cardiac events (abnormal ECG and/or elevated troponin) occurred in six of seven patients graded severe but neither stress hormones nor cardiac peptides differed significantly in patients with mild (n = 11) vs. severe (n = 7) SAH. During the course of a progressive fall in plasma sodium concentration (P = 0·001), there was a delayed activation of renin,aldosterone which was inversely correlated with declining levels of plasma ANP/BNP (P < 0·002). conclusions Excessive secretion of both ANP and BNP occurs in all patients after acute subarachnoid haemorrhage and is unrelated to severity, stress hormone activation or markers of cardiac injury. Inhibition of renin,aldosterone by cardiac hormones may impair renal sodium conservation and contribute to developing hyponatraemia. In the absence of evidence for activation of natriuretic peptides within the brain, the prompt and consistent increase in both ANP and BNP strongly supports the view that the heart is the source of increased natriuretic peptide secretion after acute subarachnoid haemorrhage. [source] | |||||||||||||