Renin-Angiotensin Aldosterone System and Fibrinolysis Interaction in Humans-Specific Aim 3

• Sponsor: Vanderbilt University (Other)
• Overall Status: Completed
• CT.gov ID: NCT00685945
• Collaborator: National Institutes of Health (NIH) (NIH), National Center for Research Resources (NCRR) (NIH), National Heart, Lung, and Blood Institute (NHLBI) (NIH)
• Enrollment: 24
• Location: 1
• Arms: 4
• Duration (Months): 13
• Patients Per Site Per Month: 1.8

Study Details

Study Description

Brief Summary

The purpose of the study is to determine if giving isosorbide,a drug that is used to treat chest pain, affects blood vessel release of an anti-clotting factor.

Condition or Disease	Intervention/Treatment	Phase
Obesity	Drug: Control (bradykinin); Drug: L-NMMA + bradykinin; Drug: Isosorbide + L-NMMA + bradykinin; Drug: Sildenafil + L-NMMA + bradykinin	N/A

Detailed Description

To test the hypothesis that the administration of the NO donor isosorbide dinitrate,but not the phosphodiesterase inhibitor sildenafil, will attenuate stimulated vascular t-PA release whereas both agents will improve glucose uptake.

Study Design

• Study Type: Interventional
• Actual Enrollment: 24 participants
• Allocation: Randomized
• Intervention Model: Crossover Assignment
• Masking: Single (Participant)
• Primary Purpose: Health Services Research
• Official Title: Renin-Angiotensin Aldosterone System and Fibrinolysis(RAAS) Interaction in Humans- Specific Aim 3
• Study Start Date: Dec 1, 2007
• Actual Primary Completion Date: Jan 1, 2009
• Actual Study Completion Date: Jan 1, 2009

Arms and Interventions

Arm	Intervention/Treatment
Experimental: Control (bradykinin infusion) Bradykinin (Clinalfa AG, Läufelfingen, Switzerland)	Drug: Control (bradykinin); Graded doses of bradykinin (Clinalfa AG, Läufelfingen, Switzerland) will be infused at 50, 100, and 200ng/min. Each dose will be infused for 5 minutes and FBF will measured during the last 2 minutes of infusion. Arterial and venous blood samples will be obtained for measurement of net t-PA release after each dose.
Experimental: L-NMMA + bradykinin N-monomethyl-L-arginine (L-NMMA, NO synthase inhibitor; Bachem, Torrance, CA)	Drug: L-NMMA + bradykinin; Thirty minutes after administration of bradykinin a continuous intra-arterial infusion of L-NMMA at 12 micromol/min will be started started. While continuing the infusion of L-NMMA, baseline measurements and infusion of bradykinin will be repeated.; Other Names: N-monomethyl-L-arginine
Experimental: Isosorbide + L-NMMA + bradykinin Isosorbide (NO donor)	Drug: Isosorbide + L-NMMA + bradykinin; Following the second bradykinin infusion, 12 subjects will receive 5mg isosorbide dinitrate (an exogenous NO donor; Major Pharmaceuticals Inc, Livonia MI). Sixty minutes after the administration of isosorbide the continuous intra-arterial infusion of L-NMMA at 12 micromol/min will be restarted and baseline measurements and bradykinin infusion will be repeated.
Experimental: Sildenafil + L-NMMA + bradykinin Sildenafil (phosphodiesterase type 5 (PDE5) inhibitor	Drug: Sildenafil + L-NMMA + bradykinin; Following the second bradykinin infusion, 12 subjects will receive 50mg sildenafil (phosphodiesterase type 5 (PDE5) inhibitor to increase cGMP without increasing NO; Pfizer, NY). Sixty minutes after the administration of sildenafil the continuous intra-arterial infusion of L-NMMA at 12 micromol/min will be restarted and baseline measurements and bradykinin infusion will be repeated.

Outcome Measures

Primary Outcome Measures

1. Net Tissue-type Plasminogen Activator (t-PA) Release [During and after each study drug administration]

   Individual net t-PA release at each time point were calculated by the following formula: net release = (Cv-CA) x {FBF x [101-hematocrit/100]}, where Cv and CA represent the concentration of t-PA in the brachial vein and artery, respectively.

Secondary Outcome Measures

1. Forearm Blood Flow (FBF) [During and after each study drug administration]

   Forearm blood flow was measured by strain gauge plethysmography

Other Outcome Measures

1. Net Glucose Uptake [At baseline and after maximum dose of bradykinin]

   Individual net reuptake rates at each time point were calculated by the following formula: net uptake = (Cv-CA) x {FBF x [101-hematocrit/100]}, where Cv and CA represent the concentration of glucose in the brachial vein and artery, respectively.

Eligibility Criteria

Criteria

• Ages Eligible for Study: 18 Years to 70 Years
• Sexes Eligible for Study: All
• Accepts Healthy Volunteers: Yes

Inclusion Criteria:

• 18-70 years of age

• Male and female subjects

• Surgical sterilization

• Childbearing potential: beta HCG on study day

• Subjects with a body mass index of 25 or greater

Exclusion Criteria:

• Diabetes type 1 to type 2 as defined by a fasting glucose of 126 mg/dl or greater or the use of anti-diabetic medication

• Use of hormone replacement therapy

• Statin therapy

• In hypertensive subjects, a seated systolic blood pressure greater than 179 mmHg or a seated diastolic blood pressure greater than 110 mmHg or taking hypertensives

• Pregnancy/Breast Feeding

• Cardiovascular disease such as myocardial infarction with 6 months prior to enrollment, presence of angina pectoris, significant arrhythmia, congestive heart failure (LV hypertrophy acceptable) deep vein thrombosis, pulmonary embolism, second or three degree heart block, mitral valve stenosis, aortic stenosis, or hypertrophic cardiomyopathy

• Treatment with anticoagulants

• History of serious neurologic disease such as cerebral hemorrhage, stroke or transient ischemic attack

• Diagnosis of asthma

• Clinically significant gastrointestinal impairment that could interfere with drug absorption

• Hematocrit <35%

• Hyperlipidemic fasting Total Cholesterol >220mg/dl

• Impaired renal function (Serum creatinine >1.5 mg/dl)

• History or presence of immunological or hematological disorders

• Any underlying or acute disease requiring regular medication which could possible pose a threat to the subject or make implementation of the protocol or interpretation of the study results difficult

• Impaired hepatic function (Serum glutamic oxaloacetic transaminase, serum glutamate pyruvate transaminase > 60)

• Treatment with chronic systemic glucocorticoid therapy (more than 7 days in 1 month)

• Treatment with lithium salts

• History of Alcohol or drug abuse

• Treatment with any investigational drug 1 month preceding study

• Mental conditions rendering the subject unable to understand the nature, scope and possible consequences of the study

• Inability to comply with the protocol

Contacts and Locations

Locations

	Site	City	State	Country	Postal Code
1	Vanderbilt University Medical Center-GCRC	Nashville	Tennessee	United States	37232

Sponsors and Collaborators

• Vanderbilt University
• National Institutes of Health (NIH)
• National Center for Research Resources (NCRR)
• National Heart, Lung, and Blood Institute (NHLBI)

Investigators

• Principal Investigator: Nancy J Brown, MD, Vanderbilt University Medical Center

Study Documents (Full-Text)

None provided.

More Information

Publications

None provided.

• Responsible Party: Nancy J. Brown, Professor of Medicine and Clinical Pharmacology, Vanderbilt University
• ClinicalTrials.gov Identifier: NCT00685945
• Other Study ID Numbers: RAAS & Fibrinolysis; 2R01HL060906; HL065193; UL1RR024975; 5R01HL085740-05
• First Posted: May 29, 2008
• Last Update Posted: Feb 25, 2013
• Last Verified: Jan 1, 2013

• Keywords provided by Nancy J. Brown, Professor of Medicine and Clinical Pharmacology, Vanderbilt University: Bradykinin; Obesity; Nitric Oxide Donor; tissue type plasminogen activator; isosorbide dinitrate; phosphodiesterase inhibitor; Renin-Angiotensin Aldosterone System; Fibrinolysis; Angiotensin converting enzyme
• Additional relevant MeSH terms: Obesity; Isosorbide; Isosorbide Dinitrate; Isosorbide-5-mononitrate; Sildenafil Citrate; Bradykinin; omega-N-Methylarginine; Kininogens

Study Results

Participant Flow

Recruitment Details	Subjects were recruited from a volunteer registry at Vanderbilt University. Subjects who participated in prior studies and requested to be contacted for future studies were included in the recruitment process. Recruitment began on 12/07 and stopped on 1/09.
Pre-assignment Detail	Subjects with renal, endocrine, hematological or cardiovascular disease (including hypertension defined as an untreated systolic/diastolic blood pressure greater than 140/90 mmHg were excluded. Subjects with a fasting cholesterol greater than 5.7 mmol/L (220 mg/dl) and smokers were excluded. No washout period was required for the study.

Arm/Group Title	All Participants
Arm/Group Description	24 subjects received a bradykinin infusion and then a bradykinin + L-NMMA infusion. Subjects were then randomized to receive either isosorbide (N=12) or sildenafil (N=12). The infusion of bradykinin + L-NMMA was then repeated.
Period Title: Control (Bradykinin Infusion)
STARTED	24
COMPLETED	24
NOT COMPLETED	0
Period Title: Control (Bradykinin Infusion)
STARTED	24
COMPLETED	23
NOT COMPLETED	1
Period Title: Control (Bradykinin Infusion)
STARTED	11
COMPLETED	11
NOT COMPLETED	0
Period Title: Control (Bradykinin Infusion)
STARTED	12
COMPLETED	12
NOT COMPLETED	0

Baseline Characteristics

Arm/Group Title	All Participants
Arm/Group Description	Subjects characteristics for all 24 participants
Overall Participants	24
Age (Count of Participants)
<=18 years	0 0%
Between 18 and 65 years	24 100%
>=65 years	0 0%
Age (years) [Mean (Standard Deviation) ]
Mean (Standard Deviation) [years]	31.71 (6.51)
Sex: Female, Male (Count of Participants)
Female	12 50%
Male	12 50%
Region of Enrollment (participants) [Number]
United States	24 100%

Outcome Measures

1. Primary Outcome

Title	Net Tissue-type Plasminogen Activator (t-PA) Release
Description	Individual net t-PA release at each time point were calculated by the following formula: net release = (Cv-CA) x {FBF x [101-hematocrit/100]}, where Cv and CA represent the concentration of t-PA in the brachial vein and artery, respectively.
Time Frame	During and after each study drug administration

Outcome Measure Data

Analysis Population Description

Twenty four subjects were studied. One subject was excluded because of erroneous drug administration. Analysis was per protocol. Twenty-three subjects receive bradykinin then L-NMMA plus bradykinin infusions. Subjects were then randomized to either isosorbide or sildenafil. Twelve subjects received sildenafil and 11 subjects received isosorbide.

Arm/Group Title	Control	L-NMMA + Control	Isosorbide + L-NMMA + Control	Sildenafil + L-NMMA + Control
Arm/Group Description	Subjects received bradykinin at 50, 100 and 200ng/min	After the intial bradykinin infusion subjects then received a continuous infusion of L-NMMA plus bradykinin at 50, 100 and 200ng/min	Eleven of the twenty-four subjects were randomized to isosorbide after completing the bradykinin and bradykinin plus L-NMMA infusions. The bradykinin plus L-NMMA infusions were then repeated.	Twelve of the twenty-four subjects were randomized to sildenafil after completing the bradykinin and bradykinin plus L-NMMA infusions. After 1 hour, bradykinin plus L-NMMA infusions were repeated.
Measure Participants	24	23	11	12
Net t-PA release (bradykinin 0ng/min)	0.24 (0.39)	0.59 (0.23)	-0.38 (0.51)	0.29 (0.67)
Net t-PA release (bradykinin 50ng/min)	1.02 (1.06)	3.65 (0.79)	3.14 (1.13)	2.46 (2.07)
Net t-PA release (bradykinin 100ng/min)	11.81 (2.12)	22.10 (5.51)	15.90 (3.13)	18.48 (9.11)
Net t-PA release (bradykinin 200ng/min)	30.03 (4.24)	39.90 (6.98)	45.32 (9.45)	37.39 (11.79)

Statistical Analysis 1

Statistical Analysis Overview	Comparison Group Selection	Control, L-NMMA + Control, Isosorbide + L-NMMA + Control, Sildenafil + L-NMMA + Control
	Comments	The effect of bradykinin on net t-PA release was determined using general linear model-repeated measures ANOVA in which the between-subject variable was gender, and the within-subjects variables were drug (control, +L-NMMA, +L-NMMA plus isosorbide, or +L-NMMA plus sildenafil) and dose of bradykinin.
	Type of Statistical Test	Superiority or Other
	Comments
Statistical Test of Hypothesis	p-Value	0.04
	Comments
	Method	ANOVA
	Comments

2. Secondary Outcome

Title	Forearm Blood Flow (FBF)
Description	Forearm blood flow was measured by strain gauge plethysmography
Time Frame	During and after each study drug administration

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	Control	L-NMMA + Control	Isosorbide + L-NMMA + Control	Sildenafil + L-NMMA + Control
Arm/Group Description	Subjects received bradykinin at 50, 100 and 200ng/min	Subjects received a continuous infusion of L-NMMA plus bradykinin at 50, 100 and 200ng/min	Twelve (of the twenty-four)subjects received isosorbide after completing the bradykinin and bradykinin plus L-NMMA infusions. The bradykinin plus L-NMMA infusions were then repeated.	Twelve (of the twenty-four) subjects received sildenafil after completing the bradykinin and bradykinin plus L-NMMA infusions. After 1 hour, bradykinin plus L-NMMA infusions were repeated.
Measure Participants	24	23	11	12
FBF (bradykinin 0 ng/min)	4.03 (0.25)	2.36 (0.18)	2.18 (0.33)	2.80 (0.37)
FBF (bradykinin 50ng/min)	7.02 (0.57)	5.16 (0.37)	4.73 (0.70)	5.87 (0.79)
FBF (bradykinin 100ng/min)	13.17 (1.04)	8.67 (0.81)	6.83 (1.13)	9.13 (0.76)
FBF (bradykinin 200 ng/min)	17.74 (1.43)	11.21 (1.12)	9.91 (1.72)	12.92 (1.30)

Statistical Analysis 1

Statistical Analysis Overview	Comparison Group Selection	Control, L-NMMA + Control, Isosorbide + L-NMMA + Control, Sildenafil + L-NMMA + Control
	Comments
	Type of Statistical Test	Superiority or Other
	Comments
Statistical Test of Hypothesis	p-Value	<0.001
	Comments
	Method	ANOVA
	Comments	Repeated measures ANOVA

3. Other Pre-specified Outcome

Title	Net Glucose Uptake
Description	Individual net reuptake rates at each time point were calculated by the following formula: net uptake = (Cv-CA) x {FBF x [101-hematocrit/100]}, where Cv and CA represent the concentration of glucose in the brachial vein and artery, respectively.
Time Frame	At baseline and after maximum dose of bradykinin

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	Control	L-NMMA + Control	Isosorbide + L-NMMA + Control	Sildenafil + L-NMMA + Control
Arm/Group Description	Subjects received bradykinin at 50, 100 and 200ng/min	Subjects received a continuous infusion of L-NMMA plus bradykinin at 50, 100 and 200ng/min	Twelve (of the twenty-four)subjects received isosorbide after completing the bradykinin and bradykinin plus L-NMMA infusions. The bradykinin plus L-NMMA infusions were then repeated.	Twelve (of the twenty-four) subjects received sildenafil after completing the bradykinin and bradykinin plus L-NMMA infusions. After 1 hour, bradykinin plus L-NMMA infusions were repeated.
Measure Participants	24	23	11	12
Net glucose uptake (bradykinin 0 ng/min)	-79.95 (22.894)	-74.36 (7.125)	-71.4 (27.74)	-67.3 (13.17)
Net glucose uptake (bradykinin 200 ng/min)	-319.85 (97.109)	-142.86 (49.935)	-163.233 (36.504)	-125.32 (45.705)

Adverse Events

Arm/Group Title	All Participants
Arm/Group Description	Subjects characteristics for all 24 participants
All Cause Mortality
	All Participants
	Affected / at Risk (%)	# Events
Total	/ (NaN)
Serious Adverse Events
	All Participants
	Affected / at Risk (%)	# Events
Total	0/24 (0%)
Other (Not Including Serious) Adverse Events
	All Participants
	Affected / at Risk (%)	# Events
Total	4/24 (16.7%)
Nervous system disorders
Headache	2/24 (8.3%)	2
fainted	1/24 (4.2%)	1
Vascular disorders
unexpected drug response	1/24 (4.2%)	1

Limitations/Caveats

[Not Specified]

More Information

Certain Agreements

Principal Investigators are NOT employed by the organization sponsoring the study.

There is NOT an agreement between Principal Investigators and the Sponsor (or its agents) that restricts the PI's rights to discuss or publish trial results after the trial is completed.