Dose response to nadolol in congenital long QT syndrome.

BACKGROUND: Beta-blocker therapy is the cornerstone of treatment for patients with long QT syndrome (LQTS). Few details on the dose to be used are available. As the response is variable between patients, we systematically evaluated the effect of treatment by performing an exercise test. OBJECTIVE: The purpose of this study was to explore dose response to nadolol on exercise test in LQTS patients in order to propose a more personalized therapeutic approach. METHODS: LQTS patients followed at the Reference Centre for Hereditary Arrhythmic Diseases of Nantes with at least 1 exercise test under nadolol were included retrospectively between 1993 and 2017. All patients underwent gradual cycle exercise tests. Doses adjusted to weight and response to treatment were recorded and evaluated by the percentage of age-predicted maximum heart rate reached on exercise test. RESULTS: Ninety-five patients were included in the study, and 337 stress tests under nadolol were analyzed. No correlation existed between dose and percentage of age-predicted maximum heart rate on exercise tests. Twenty-one patients were overresponders, mostly LQTS1, and 20 were underresponders, mainly LQTS2 (P = .0229). Forty-two patients had at least 3 stress tests under nadolol. We found a negative correlation between dose change and percentage of age-predicted maximum heart rate change (P <.0001). We then proposed a table to adapt dose according to exercise test response. CONCLUSION: Our study demonstrated a major variability of dose response to nadolol in patients with LQTS, thus underlining the need for a tailored dosage for each patient. Intraindividual analysis showed a relatively constant dose-response relationship, allowing guided dose adaptation after the first exercise test.

Systemic ß-Adrenergic Receptor Activation Augments the ex vivo Expansion and Anti-Tumor Activity of Vγ9Vδ2 T-Cells.

TCR-gamma delta (γδ) T-cells are considered important players in the graft-vs.-tumor effect following allogeneic hematopoietic cell transplantation (alloHCT) and have emerged as candidates for adoptive transfer immunotherapy in the treatment of both solid and hematological tumors. Systemic ß-adrenergic receptor (ß-AR) activation has been shown to mobilize TCR-γδ T-cells to the blood, potentially serving as an adjuvant for alloHCT and TCR-γδ T-cell therapy. We investigated if systemic ß-AR activation, using acute dynamic exercise as an experimental model, can increase the mobilization, ex vivo expansion, and anti-tumor activity of TCR-γδ T-cells isolated from the blood of healthy humans. We also sought to investigate the ß-AR subtypes involved, by administering a preferential ß1-AR antagonist (bisoprolol) and a non-preferential ß1 + ß2-AR antagonist (nadolol) prior to exercise as part of a randomized placebo controlled cross-over experiment. We found that exercise mobilized TCR-γδ cells to blood and augmented their ex vivo expansion by ~182% compared to resting blood when stimulated with IL-2 and ZOL for 14-days. Exercise also increased the proportion of CD56+, NKG2D+/CD62L-, CD158a/b/e+ and NKG2A- cells among the expanded TCR-γδ cells, and increased their cytotoxic activity against several tumor target cells (K562, U266, 221.AEH) in vitro by 40-60%. Blocking NKG2D on TCR-γδ cells in vitro eliminated the augmented cytotoxic effects of exercise against U266 target cells. Furthermore, administering a ß1 + ß2-AR (nadolol), but not a ß1-AR (bisoprolol) antagonist prior to exercise abrogated the exercise-induced enhancement in TCR-γδ T-cell mobilization and ex vivo expansion. Furthermore, nadolol completely abrogated while bisoprolol partially inhibited the exercise-induced increase in the cytotoxic activity of the expanded TCR-γδ T-cells. We conclude that acute systemic ß-AR activation in healthy donors markedly augments the mobilization, ex vivo expansion, and anti-tumor activity of TCR-γδ T-cells and that some of these effects are due to ß2-AR signaling and phenotypic shifts that promote a dominant activating signal via NKG2D. These findings highlight ß-ARs as potential targets to favorably alter the composition of allogeneic peripheral blood stem cell grafts and improve the potency of TCR-γδ T-cell immune cell therapeutics.

Nadolol for Treatment of Supraventricular Tachycardia in Infants and Young Children.

Supraventricular tachycardia (SVT) is a common infant arrhythmia, for which beta-blockers are frequently chosen as therapy. Propranolol is a common choice though it is dosed every 6-8 h. We reviewed the clinical results of treating infant SVT with an extemporaneous preparation of nadolol. Retrospective cohort study of patients under 2 years old receiving nadolol for SVT at a single center. Patients were ascertained by patient and pharmacy databases. Twenty-eight infants received nadolol, of whom 25 had regular narrow complex tachycardia, 2 atrial flutter, and 1 focal atrial tachycardia. Patient age at initiation was a median 54 days (range 10-720). The final dose was 1 mg/kg/day in 22/28 patients (range 0.5-2). Once-daily dosing was used in 20 patients (71.4%); dosing was BID in 7, TID in 1. Among regular narrow complex tachycardia patients, 18/25 received nadolol monotherapy and 7 required additional agents; flecainide in 6, digoxin in 1. The median age of tachyarrhythmia onset was 18 days (range 1-180) with a median age of nadolol initiation of 30 days (range 11-390). Of the 20 regular narrow complex tachycardia patients initiated on nadolol monotherapy, 85% had no recurrences as of 1-year follow-up. Side effects were suspected in 3 of 28 (10.7%), including wheezing (n = 1, 3.5%), irritability and diarrhea (n = 1, 3.5%), and bradycardia (n = 1, 3.5%). Oral nadolol suspension was a successful treatment for SVT in 85% of patients with minimal adverse effects. Single daily dosing was used in the majority of patients.

Nadolol decreases the incidence and severity of ventricular arrhythmias during exercise stress testing compared with ß1-selective ß-blockers in patients with catecholaminergic polymorphic ventricular tachycardia.

BACKGROUND: Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an inheritable cardiac disease predisposing to malignant ventricular arrhythmias. OBJECTIVE: We aimed to explore the incidence and severity of ventricular arrhythmias in patients with CPVT before the initiation of ß-blocker treatment, when treated with ß1-selective ß-blockers, and when treated with nadolol. METHODS: In this study, 34 patients with CPVT were included (mean age 34 ± 19 years; 15 (44%) women; 30 (88%) ryanodine receptor 2 variant positive). We performed 3 bicycle exercise stress tests in each patient: (1) before the initiation of ß-blocker treatment, (2) after >6 weeks of treatment with ß1-selective ß-blockers and (3) after >6 weeks of treatment with nadolol. We recorded resting and maximum heart rates and the most severe ventricular arrhythmia occurring. Severity of arrhythmias was scored as 1 point for no arrhythmias or only single ventricular extrasystoles, 2 points for >10 ventricular extrasystoles per minute or bigeminy, 3 points for couplets, and 4 points for nonsustained ventricular tachycardia or sustained ventricular tachycardia. RESULTS: Resting heart rate was similar during treatment with nadolol and ß1-selective ß-blockers (54 ± 10 beats/min vs 56 ± 14 beats/min; P = .50), while maximum heart rate was lower during treatment with nadolol compared with ß1-selective ß-blockers (122 ± 21 beats/min vs 139 ± 24 beats/min; P = .001). Arrhythmias during exercise stress testing were less severe during treatment with nadolol compared with during treatment with ß1-selective ß-blockers (arrhythmic score 1.6 ± 0.9 vs 2.5 ± 0.8; P < .001) and before the initiation of ß-blocker treatment (arrhythmic score 1.6 ± 0.9 vs 2.7 ± 0.9; P = .001); however, no differences were observed during treatment with ß1-selective ß-blockers compared with before the initiation of ß-blocker treatment (arrhythmic score 2.5 ± 0.8 vs 2.7 ± 0.9; P = .46). CONCLUSION: The incidence and severity of ventricular arrhythmias decreased during treatment with nadolol compared with during treatment with ß1-selective ß-blockers. ß1-Selective ß-blockers did not change the occurrence or severity of arrhythmias compared with no medication.

Bidirectional Modulation of Alcohol-Associated Memory Reconsolidation through Manipulation of Adrenergic Signaling.

Alcohol addiction is a problem of great societal concern, for which there is scope to improve current treatments. One potential new treatment for alcohol addiction is based on disrupting the reconsolidation of the maladaptive Pavlovian memories that can precipitate relapse to drug-seeking behavior. In alcohol self-administering rats, we investigated the effects of bidirectionally modulating adrenergic signaling on the strength of a Pavlovian cue-alcohol memory, using a behavioral procedure that isolates the specific contribution of one maladaptive Pavlovian memory to relapse, the acquisition of a new alcohol-seeking response for an alcohol-associated conditioned reinforcer. The ß-adrenergic receptor antagonist propranolol, administered in conjunction with memory reactivation, persistently disrupted the memory that underlies the capacity of a previously alcohol-associated cue to act as a conditioned reinforcer. By contrast, enhancement of adrenergic signaling by administration of the adrenergic prodrug dipivefrin at reactivation increased the strength of the cue-alcohol memory and potentiated alcohol seeking. These data demonstrate the importance of adrenergic signaling in alcohol-associated memory reconsolidation, and suggest a pharmacological target for treatments aiming to prevent relapse through the disruption of maladaptive memories.

Oral Nadolol for Children with Infantile Hemangiomas and Sleep Disturbances with Oral Propranolol.

BACKGROUND/OBJECTIVE: Oral propranolol has been shown to be safe and effective in infants with infantile hemangioma (IH). Side effects such as sleep disturbances have been associated with propranolol. The aim of this study was to evaluate the efficacy and safety of oral nadolol in a small series of patients whose propranolol therapy was discontinued due to sleep disturbances. METHODS: A retrospective study of patients with IHs who were treated with oral nadolol due to propranolol-related sleep disturbances at a pediatric tertiary care center between July 2008 and March 2013. Clinical response to oral nadolol and disappearance of propranolol-related side effects were analyzed. RESULTS: A total of 97 patients presenting IH received oral propranolol. Nine patients (9.3%) developed sleep disturbances. Oral propranolol was discontinued in seven patients and switched to oral nadolol, with resolution of these side effects in 5 (71%) of the cases. One patient developed sleep disturbances again after four months of oral nadolol. LIMITATIONS: The sample size was too small to draw generalizable conclusions and to draw any statistical inference as to the incidence of sleep disturbances with nadolol therapy. CONCLUSIONS: The use of oral nadolol in the treatment of IH in our series of 7 patients, resolved the propranolol-related sleep disturbances in 5 (71%), while in one patient the symptoms recurred after 4 months of oral nadolol at a dose of 2 mg/kg/day. In most cases, switching beta-blockers did not compromise efficacy, and is recommended when sleep disturbance necessitates discontinuation of beta-blocker therapy of IH.

Oral Nadolol for the Treatment of Infantile Hemangiomas: A Single-Institution Retrospective Cohort Study.

BACKGROUND: Beta-blockers have become the treatment of choice for problematic infantile hemangiomas (IHs). Nadolol, a nonselective beta-blocker with potential dosing advantages and a better safety profile than that of other beta-blockers, has been studied as an alternative therapeutic option. Our objective was to characterize the efficacy and safety of oral nadolol in the treatment of proliferating IHs. METHODS: A retrospective cohort study was conducted at the Hospital for Sick Children between February 2010 and April 2012 in patients treated with nadolol for proliferating IHs causing functional impairment or cosmetic disfigurement. The primary outcome was the percentage involution measured independently by two assessors who scored changes in the extent of IHs by comparing serial photographs using a 100-mm visual analogue scale (VAS), on which 5 mm represented 10% change. RESULTS: Forty-four patients treated with nadolol for IHs with adequate photographic documentation were identified. The median age at presentation was 4.5 months (interquartile range 1.5-7.9 mos). There was a mean improvement of 91.8 ± 11.1%. At least 50% improvement was noted in 42 (95%) patients and 75% improvement in 39 (89%) patients. The mean time to 50% and 75% improvement was 2.9 and 3.7 months, respectively. Analysis of variance showed that younger age at the time of treatment start was associated with a higher mean VAS score (% involution) (p < 0.05). Treatment duration (mean 9.5 ± 5.6 months) had no significant effect on VAS score. Test of interobserver correlation showed good agreement (intraclass correlation coefficient = 0.86, p = 0.001). CONCLUSIONS: Oral nadolol is efficacious in patients with problematic IHs. Further large-scale prospective comparative studies are warranted to compare nadolol with other beta-blockers.

Right ventricular outflow tract tachycardia worsened during pregnancy.

We report the case of a 35 years old woman without underlying heart disease who was diagnosed with a right ventricular outflow tract tachycardia worsened during pregnancy. The diagnosis of ventricular tachycardia was made early in her pregnancy course but the patient had symptoms three months earlier. Her disease course was marked by rhythmic storms during the second trimester of pregnancy that led to three hospitalizations accounting for about two weeks in total. The combination of nadolol 80 mg and flecainide tablets 150 mg improved her rhythmic storms. Radiofrequency allowed a radical cure of this ventricular tachycardia. The patient is now asymptomatic 27 months after radiofrequency treatment.

Transmissão hereditária da morte súbita cardíaca nas canalopatias / Hereditary transmission of sudden cardiac death in channelopathies

O caso clínico sugere uma forma rara de canalopatia mista, cujo sintoma clínico e eletrocardiográfico indicava taquicardia ventricular polimórfica catecolaminérgica (TVPC). Porém, ao realizar o teste ergométrico, no pós-esforço, quando há predomínio do sistema nervoso parassimpático, nota-se a indução de eletrocardiograma (ECG) compatível com Brugada do tipo I. Outro aspecto importante foi a transmissão hereditária observada neste caso, em que os avós do paciente eram primos de primeiro grau e houve seis casos de morte súbita cardíaca (MSC) nas gerações subsequentes, com irmão que teve MSC aos 5 anos durante uma crise de choro, mostrando um importante fator genético e familiar relacionado às canalopatias.

The clinical case suggests a rare form of mixed channelopathy, whose clinical and electrocardiographic symptom suggested catecholaminergic polymorphic ventricular tachycardia (CPVT). However, when the exercise test was performed, during post-exercise, where there is a predominance of the parasympathetic nervous system, there was an electrocardiogram (ECG) induction compatible with Brugada type I. Another important aspect was the hereditary transmission observed in this patient, whose grandfathers were first cousins, and 6 cases of sudden cardiac death (SCD) were observed in subsequent generations and one brother had SCD at 5 years of age during a crying episode, showing an important genetic and familial factor related to channelopathies.

ß Blockers for prevention of exercise-induced left ventricular outflow tract obstruction in patients with hypertrophic cardiomyopathy.

Whether treatment with ß blockers (BBs) is of benefit to patients with hypertrophic cardiomyopathy (HC) and provocable outflow obstruction (with none or with only mild heart failure symptoms) is largely unresolved. Thus, we prospectively studied 27 patients with HC (age 36 ± 15 years; 81% men) with New York Heart Association class I or II, without obstruction at rest, but with exercise-induced left ventricular outflow tract (LVOT) gradient of ≥ 30 mm Hg. Patients underwent exercise echocardiography at baseline and after treatment with nadolol (n = 18; 40 to 80 mg/day) or bisoprolol (n = 9; 5 to 10 mg/day), according to a prespecified protocol. Without the BBs, the postexercise LVOT gradient was 87 ± 29 mm Hg and >50 mm Hg in 25 patients (93%). After a 12 ± 4-month period of BB treatment, the postexercise LVOT gradient had decreased to 36 ± 22 mm Hg (p <0.001) and was virtually abolished (to 0 or <30 mm Hg) in 14 patients (52%), substantially blunted (≥ 20 mm Hg reduction) in 9 (33%), and unchanged in only 4 (15%). Severe postexercise obstruction (range 58 to 80 mm Hg) persisted in 6 patients (22% compared to 93% without BBs; p <0.001). Nonresponders (residual postexercise gradient of ≥ 30 mm Hg with BBs) were characterized by an increased body mass index (hazard ratio 2.03/1 kg/m(2), 95% confidence interval 1.2 to 3.4; p <0.05). In conclusion, in patients with HC with mild or no symptoms, treatment with BBs can prevent the development of LVOT obstruction triggered by physiologic exercise. These findings provide a rationale for the novel strategy of early prophylactic pharmacologic treatment with standard, well-tolerated doses of BBs in physically active patients with provocable gradients, aimed at effective prevention of the hemodynamic burden associated with dynamic obstruction.

Oral ß-blockade in relation to energy expenditure in clinically stable patients with liver cirrhosis: a double-blind randomized cross-over trial.

Elevated resting energy expenditure (REE) is seen in liver cirrhosis and is associated with reduced transplant-free survival. Non-selective ß-blockers reduce REE in acute hypermetabolic conditions. We examined whether non-selective ß-blockers reduce REE in patients with stable liver cirrhosis. Twenty-two stable cirrhotic patients (Child-Pugh grading: 19A, 2B, 1C) were randomized to 3-month treatment with nadolol (titrated to decrease resting pulse rate by 20%) or placebo and after a 1-month washout period crossed to the alternative treatment for a further 3 months. REE was measured by indirect calorimetry and total body protein by neutron activation analysis at the beginning and end of each 3-month period of treatment. A predicted REE was calculated for each patient based on total body protein. A measured to predicted REE ratio >1.22 indicated significantly elevated REE. The primary outcome was REE at the end of 3-month treatment with nadolol compared with placebo. Elevated REE was seen in one patient at study entry. After 3 months on placebo REE was 1506±40 (SEM) kcal/d and on nadolol, 1476±40 kcal/d, a mean reduction of 31±16 kcal/d (P=.076). Total body protein changes were not significant. Nadolol was well tolerated with no increase in the rate of adverse events. In stable cirrhotic patients, nadolol was not associated with reduction in REE. A larger, longer-term study with different eligibility criteria is required to investigate whether this treatment offers benefits additional to its use for prevention of variceal hemorrhage.

The effects of acute and chronic nadolol treatment on ß2AR signaling in HEK293 cells.

Nadolol (NAD) is a ß-adrenergic receptor blocker with inverse agonist activity at ßARs. Previous studies in our laboratory showed that chronic treatment with NAD decreased airway resistance response (R (aw)) to the muscarinic agonist methacholine in a murine model of asthma while acute treatment with NAD increased R (aw) (Callaerts-Vegh et al., Proc Natl Acad Sci U S A 101:4948-4953, 2004). Chronic treatment with NAD also caused decreased airway inflammation and mucin content in a murine asthma model (Nguyen et al., Am J Respir Cell Mol Biol 38:256-262, 2008). In this study, we examined the effects of nadolol on ß(2)AR levels and signaling components downstream of the ß(2)AR using a line of HEK293 cells expressing human ß(2)ARs. Chronic treatment with NAD increased ß(2)AR protein levels and decreased receptor degradation, consistent with receptor stabilization by the inverse agonist. Basal cAMP levels decreased after 5 min of treatment with NAD but increased after a 24-h treatment. A 5-min treatment with NAD decreased forskolin-stimulated phosphorylation at the ß(2)AR PKA site Ser 262 while a 24-h treatment with NAD increased it. In contrast, chronic treatment with NAD had no effect on phosphorylation of the ß(2)AR GRK site at Ser 355, 356. Chronic treatment with NAD upregulated cellular levels of G(α)s but had no effect on G(α)i. Chronic NAD treatment therefore increases cellular cAMP levels by mechanisms that include the upregulation of ß(2)AR and G(α)s. This effect may explain in part the beneficial effects of chronic nadolol treatment on airway contractility.

A specialized, nurse-run titration clinic: a feasible option for optimizing beta-blockade in non-clinical trial patients.

OBJECTIVES: Randomized controlled trials of variceal bleeding prophylaxis demonstrate beta-blocker (BB) withdrawal rates of about 15%. We aimed to evaluate the dosing and tolerance of BBs achievable in a specialized, nurse-run BB titration clinic with non-trial participants. METHODS: We analyzed prospectively collected data from 154 patients seen at the clinic between 2004 and 2009. BBs were titrated to patient tolerance. The therapeutic target (TT) was defined as a heart rate between 50 and 60 beats per minute (bpm) on the last clinic visit and/or maximum doses of BBs (propranolol 320 mg, nadolol 160 mg). RESULTS: Eight of 154 patients were lost to follow-up, leaving 146. Fifty-five percent were male (mean age, 55; mean model for end-stage liver disease (MELD) score, 9), with 74% Child-Pugh class A. Median end-of-study doses were 120 mg propranolol and 60 mg nadolol. Seventy-nine percent of patients reached the TT before they were discharged from the clinic. Side effects were experienced by 72% of patients. Thirty-four percent had no need for dose reduction; 17% required transient dose reduction, 16% permanent dose reduction, and 5% BB discontinuation. Among patients requiring permanent dose reduction or discontinuation, the top reasons were fatigue and orthostatic symptoms. Independent predictors of achieving higher doses of BB were the absence of side effects, younger age, and diabetes. CONCLUSIONS: This study provides evidence that a specialized BB titration clinic attains low withdrawal rates and higher doses, similar to those in clinical trials. Nurse-led clinics can contribute to successful titration of these important medications.

Effects of ß-adrenoceptor antagonists on alcohol drinking by alcohol-dependent rats.

RATIONALE: Alcohol-dependent animals display enhanced stress responsivity, reward thresholds, and alcohol self-administration during alcohol withdrawal, and some of these aspects of alcohol dependence may be mediated by activation of brain norepinephrine (NE) systems. OBJECTIVES: This study examined the effects of propranolol, a ß-adrenoceptor antagonist, on operant alcohol-reinforced responding by alcohol-dependent and non-dependent rats. METHODS: Adult male Wistar rats were trained to respond for alcohol in an operant conditioning paradigm on fixed-ratio-1 (FR-1) and progressive ratio (PR) reinforcement schedules. Rats were either made dependent on alcohol via chronic intermittent (14 h ON/10 h OFF) alcohol vapor inhalation or were not exposed to alcohol vapor. Rats were tested for the effects of propranolol (0-10 mg/kg) or nadolol (0-20 mg/kg) on operant alcohol-reinforced responding at the time point corresponding to 6-8 h withdrawal in dependent animals. RESULTS: All doses of propranolol suppressed FR-1 operant alcohol-reinforced responding in alcohol-dependent rats, but only the highest dose suppressed FR-1 responding by controls. No dose of propranolol affected water responding. Nadolol did not affect operant behavior. Propranolol suppressed PR operant alcohol-reinforced responding across groups, an effect attributable to significant suppression of alcohol responding at the highest dose. CONCLUSIONS: Following development of alcohol dependence, rats exhibit hypersensitivity to the suppressive effects of propranolol on operant alcohol-reinforced responding. This effect is mediated by central actions of the drug, is not attributable to motor effects, and may reflect activation of brain NE systems that contributes to withdrawal-induced negative emotional states and drives alcohol drinking in the dependent organism.

High doses of beta-blockers and alcohol abstinence improve long-term rebleeding and mortality in cirrhotic patients after an acute variceal bleeding.

BACKGROUND & AIM: We analysed prognostic indicators of long-term outcome in cirrhotic patients surviving the critical 6-week period after an episode of acute variceal bleeding. METHODS: All patients with oesophageal variceal bleeding from 2001-2007 were prospectively registered. Follow-up extended from day 42 after index bleeding to last visit, death or liver transplantation (LT). Multivariate Cox regression analysis was performed. RESULTS: Two hundred and fifty variceal bleeding episodes were registered. Fifty-four patients (26%) died before day 42, and 123 patients were finally included. Median follow-up was 23.5 months. Nadolol+/-nitrates alone or combined with variceal ligation were used as prophylaxis in 93% of patients. During follow-up, 43 patients (35%) experienced rebleeding, 34 (27.5%) died and 10 (8%) were transplanted. Follow-up beta-blocker dose (HR 0.993, 95% CI 0.987-0.998, P=0.027) and alcohol abstinence (HR 0.324, 95% CI 0.152-0.691, P=0.004) were independent rebleeding predictors. The Cox analysis disclosed the Child-Pugh score (HR 1.24, 95% CI 1.08-1.43, P=0.002), creatinine (HR 1.82, 95% CI 1.17-2.82, P=0.008), beta-blocker dose (HR 0.992, 95% CI 0.987-0.997, P=0.003), viral cirrhosis (HR 2.72, 95% CI 1.31-5.67, P=0.008), hepatocellular carcinoma (HR 9.44, 95% CI 3.54-25.20, P<0.001) and alcohol abstinence (HR 0.29, 95% CI 0.13-0.62, P=0.002) to be independent prognostic markers for mortality/LT. CONCLUSION: High doses of beta-blockers and alcohol abstinence decrease rebleeding and mortality in cirrhotic patients surviving the 6-week period after acute variceal bleeding.

Effect of nadolol injected prior to CRH on stress-induced plasma corticosterone level in rat.

The proposed research is the part of our investigation of the role of catecholamines in the alterations provoked by stress. Especially, we elucidate if Nadolol injected prior to CRH ICV has some effect on plasma corticosterone level. 15 mg/kg of Nadolol (the dose sufficient to prevent CRH-induced increases in heart-rate for 2 hr), dissolved in saline was administered intraperitoneally, 30 minutes prior to CRH (The dose of interest for CRH - 1 mkg/kg - was determined earlier, as provoking the maximal increase of plasma corticosterone level after 20 minutes of its ICV injection). Whole blood was collected at 11.00 am, via indwelling jugular catheter at 0 (control) and 15 minutes after Nadolol injection, also 30 and 60 min after CRH injection. After centrifugation the plasma level of corticosterone was essayed using ELISA method. 15 minutes after Nadolol injection the level of plasma corticosterone in comparing with control wasn't changed, at subsequent time-points plasma corticosterone level was increased but significant difference was observed only after 30 minutes. Thus, according our results, 30 min after injection, the dose of Nadolol, sufficient to prevent CRH-induced increase in heart rate, doesn't preclude the CRH-induced increase of plasma corticosterone - one of key signs of the stress-axis activation. The results were discussed.