| Outcome Measures: |
Primary: Forearm Blood Flow, Forearm blood flow measured by strain gauge plethysmography in response to 1.0 nmol/min neuropeptide Y, the highest dose that all received., FBF measured after 5 min of the 1 nmol/min dose of neuropeptide Y on study days 1 and 2. Study days 1 and two were separated by five weeks. | Secondary: Arterial Norepinephrine, Arterial norepinephrine concentration measured by high-performance liquid chromatography., Measured at baseline (time 0) prior to the infusion of neuropeptide Y on each study day. Study days 1 and 2 were separated by five weeks.|Venous Norepinephrine, Venous norepinephrine concentration measured by high-performance liquid chromatography, Measured at baseline (time 0) prior to the infusion of neuropeptide Y on each study day. Study days 1 and 2 were separated by five weeks.|NPY Metabolites, NPY (3-36) concentration measured by micro ultra-hgih pressure liquid chromatography tandem mass spectrometry. NPY (3-36) is the degradation product of NPY by dipeptidyl peptidase 4. It was measured only in the diabetics studied., Measured after 5 min infusion of the 1.0 nmol/min dose of neuropeptide Y on study days 1 and 2. Study days 1 and 2 were separated by five weeks.|Insulin, Plasma insulin measured by radioimmunoassay., Measured at baseline (time 0) of each study day prior to the infusion of neuropeptide Y. Study days 1 and 2 were separated by five weeks, a four-week washout and one-week treatment period.|GLP-1, GLP--1 was not analyzed as subjects were studied in the fasting state., Measured at baseline (time 0) of each study day prior to the infusion of neuropeptide Y. Study days were separated by five weeks, a four-week washout and one-week treatment period.|Glucose, Glucose was measured by the glucose oxidase method using a YSI glucose analyzer, Measured at baseline (time 0) of each study day prior to the infusion of neuropeptide Y. Study days were separated by five weeks, a four-week washout and one-week treatment period.|ACE Activity, ACE activity was measured using a commercially available assay (Olympus AU400/AU600, Alpco Diagnotics, Salem, NH.) The lower level of detection was 15 U/L and values below the level of detection were reported at half the level of detection., Measured at baseline (time 0) of each study day prior to the infusion of neuropeptide Y. Study days were separated by five weeks, a four-week washout and one-week treatment period.|DPP4 Activity, DPP4 activity was measured by detection of cleavage of a colorimetric substrate., Measured at baseline (time 0) of each study day prior to the infusion of neuropeptide Y. Study days were separated by five weeks, a four-week washout and one-week treatment period.|Low Frequency Variability of Blood Pressure Activity, Measured using the VITAL-GARD 450c monitor Ivy Biomedical Systems, Branford, CT, USA), Measured at baseline (time 0) of each study day prior to the infusion of neuropeptide Y. Study days were separated by five weeks, a four-week washout and one-week treatment period.|Arterial tPA, Measured using an ELISA., Measured at baseline (time 0) of each study day prior to the infusion of neuropeptide Y. Study days were separated by five weeks, a four-week washout and one-week treatment period.|Venous tPA, Measured using an ELISA. This was measured in a few subjects. After it was determined that there was no change in net t-PA release it was not measured in the remainder., Measured at baseline (time 0) of each study day prior to the infusion of neuropeptide Y. Study days were separated by five weeks, a four-week washout and one-week treatment period.|Mean Arterial Pressure, Measured at baseline (time 0) of each study day prior to the infusion of neuropeptide Y. Study days were separated by five weeks, a four-week washout and one-week treatment period.|Heart Rate, Measured at baseline (time 0) of each study day prior to the infusion of neuropeptide Y. Study days were separated by five weeks, a four-week washout and one-week treatment period.
|
