Pharmacokinetics Study of Gamma-aminobutyric Acid (GABA-PK)
The purpose of this study is to determine upon administering GABA orally to a person how it is absorbed, distributed, as well as the drug's pharmacological effects on the body such as glucose levels, serum C-peptide and/or insulin levels (referred to as pharmacokinetics/pharmacodynamics). We will conduct experiments in normal subjects to address these questions.
Diabetes Mellitus, Type 1
Glucose Metabolism Disorders
Endocrine System Diseases
Immune System Diseases
|Study Design:||Time Perspective: Prospective|
|Official Title:||The Pharmacokinetics of Gamma-aminobutyric Acid in Healthy Volunteers.|
- pharmacokinetic characteristics of γ-aminobutyric acid (GABA) [ Time Frame: baseline and up to 30 days ] [ Designated as safety issue: No ]
The primary endpoint of this study is to obtain the pharmacokinetic characteristics of γ-aminobutyric acid (GABA), including:
- Area under the plasma concentration-time curve from time 0 to the last quantifiable concentration (AUC0-t),
- Area under the plasma concentration-time curve from time 0 extrapolated to infinity (AUC0-∞),
- Maximum observed plasma concentration (Cmax),
- Time to maximum plasma concentration (Tmax), and
- Terminal elimination half-life in plasma (t½)
- serological characteristics [ Time Frame: baseline and up to 30 days ] [ Designated as safety issue: No ]plasma glucose levels, insulin, C-peptide and glucagon levels will be measured
- Exploratory measures [ Time Frame: baseline and up to 30 days ] [ Designated as safety issue: No ]plasma glucagon-like peptide-1 (GLP-1) and glycated serum protein (GSP)will be measured.
Biospecimen Retention: Samples Without DNA
This is an open-labeled, 3-phase, self-control study. In phase 1, blood is sampled from volunteers who will take placebo to obtain the baseline value. In phase 2, volunteers will take a single oral dose of 2000 mg GABA. There are at least 7 days between the two phases. In phase 3, volunteers will take a repeated oral dose of 2000 mg GABA (thrice daily for seven days). There are at least 5-7 days between phase 3 and phase 3. In each phase, individuals will be observed for 24 hours to obtain the complete concentration time curve. 4 ml of blood will be sampled at the following time-point for predose and 0.25, 0.5, 0.75, 1, 1.5, 2, 3, 4, 6, 8, 10, 12 and 24 hour postdose.
|Study Start Date:||July 2013|
|Estimated Study Completion Date:||July 2014|
|Estimated Primary Completion Date:||February 2014 (Final data collection date for primary outcome measure)|
Type 1 diabetes is an autoimmune disease resulting from the progressive loss of pancreatic insulin-secreting beta-cells. This consequently leads to a lack of insulin and elevation of blood sugar, namely hyperglycemia, which is a major cause for the development of diabetes and its acute or chronic complications. The current treatment for type 1 diabetes requires a life-long dependency on daily insulin injections, causing inconvenience and burden to patients. Drug-induced hypoglycemia is also common as it presents a major challenge in insulin therapy. Furthermore, although insulin therapy is lifesaving, it is not a cure as it neither reverses the progression of the disease nor prevents the development of serious complications associated with this disease. New treatments are urgently needed.
Recent studies have demonstrated that a natural chemical found in the brain, gamma-aminobutyric acid (GABA), which is also produced in large quantities by pancreatic beta-cells, has beta-cell regenerative and immunoregulatory effects. Importantly, GABA prevented and partially reversed diabetes in type 1 diabetes mouse models. It is important to address essential questions regarding the potential effects of GABA in diabetic patients in humans. Given the largely unknown mechanism of action of GABA in the pancreas, and the limited information on how GABA is absorbed, distributed and eliminated from the human body, we plan to examine these issues (referred to as pharmacokinetics/pharmacodynamics) in normal subjects.
The outcome of this study will provide useful information on the mechanism of action of GABA in human subjects.
Please refer to this study by its ClinicalTrials.gov identifier: NCT01917760
|Department of Endocrinology and Metabolism，Huashan hospital||Recruiting|
|Shanghai, Shanghai, China, 200040|
|Contact: Zhaoyun Zhang, MD, PhD 021- 5288-8286 firstname.lastname@example.org|
|Contact: Yi Wang, MD, PhD 021- 5288-7022 email@example.com|
|Principal Investigator: Yiming Li|
|Principal Investigator: Qinghua Wang|
|Principal Investigator: Zhen Jiao|
|Principal Investigator:||Yiming Li||Huashan Hospital|
|Principal Investigator:||Qinghua Wang||Huashan Hospital/St Michael's Hospital|
|Principal Investigator:||Zheng Jiao||Huashan Hospital|