The relationship between central serotonergic activity and insulin sensitivity in healthy volunteers.
In order to determine whether central serotonin (5-HT) activity is related to sensitivity of insulin receptors, 19 healthy volunteers with normal basal glycemia and HbAlc were studied. The relationship between prolactin response to D-fenfluramine (delta PRL) in a challenge test and metabolic clearance rates (MCR) of glucose during the hyperinsulinemic-euglycemic clamp technique was evaluated. delta PRL had been chosen as a correlate of central 5-HT activity. Two levels of insulin concentration of approximately 70 mU/l (MCRsubmax) and 2000 mU/l (MCRmax) were used in a clamp, each for a duration of 120 min. A negative correlation was found between delta PRL and MCRsubmax (r = -0.55, P < 0.02) and between delta PRL and MCRmax (r = -0.51, P < 0.03). We did not find any correlation between the prolactin response to D-fenfluramine and body weight, body mass index (BMI) or waist and hip circumference (WHR). The data support the hypothesis of a close connection between 5-HT activity in the brain and peripheral sensitivity to insulin. The possible physiological mechanisms of this connection are discussed.
Horácek
J
J
3rd Faculty of Medicine, Charles University, Prague, Czech Republic. horacek@pcp.lf3.cuni.cz
Kuzmiaková
M
M
Höschl
C
C
Andĕl
M
M
Bahbonh
R
R
D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D001824:Body Constitution; D015992:Body Mass Index; D001921:Brain / Q000502:physiology*; D005277:Fenfluramine; D015309:Glucose Clamp Technique; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D007333:Insulin Resistance / Q000502:physiology; D008297:Male; D011388:Prolactin / Q000097:blood; D011972:Receptor, Insulin / Q000502:physiology*; D012701:Serotonin / Q000502:physiology*; D018490:Serotonin Agents
D001786:Blood Glucose; D005277:Fenfluramine; D006442:Glycated Hemoglobin; D011388:Prolactin; D011972:Receptor, Insulin; D012701:Serotonin; D018490:Serotonin Agents