|Figure 1: Basal glucose & insulin levels in DIO & DR mice after 2 weeks on placebo (P), bromocriptine (B) or haloperidol (H) (data adapted from de Leeuw van Weenen. 2011)|
What de Leeuw van Weenen et al (de Leeuw van Weenen. 2011) found in the same diet induced obesity [DIO] mouse model Ravussin (Ravussin. 2011)had used in his study (cf. Follow Up on Set-Point Theories: Could Royal Jelly Help With Obesity / Diet Induced Structural Brain Changes?) were
- altered dopaminergic transmission
- exaggerated basal and feeding-evoked dopamine release
- reduced dopaminergic receptor (DRD2) activity and number of binding sites
[...] profound effects on energy homeostasis in humans and animals. Drugs that blockDRD2 enhance appetite and induce weight gain in animals and human. Conversely, DRD2 agonist drugs reduce body weight, increase energy expenditure, and improve glycemic control in obese animals and individuals.
To verify the efficacy of respective drugs, the researchers administered Bromocriptine (DRD2 agonist) and Haloperidol (DRD2 antagonist) to DIO and diet resistant [DR], i.e. naturally lean mice, and found that ...
|It does not take Bromocriptine |
L-Dopa from Mucuna Pruriens
is a natural and proven
precursor to dopamine.
Haloperidol treatment reduced the voluntary activity and energy expenditure of DR mice and induced insulin resistance in these mice. Conversely, bromocriptine treatment tended to reduce bodyweight and voluntary activity, and reinforce insulin action in DIO mice.Taken together these results / effects of reduced dopaminergic tone
- decreased insulin sensitivity, hyperglycemia
- decreased voluntary movement and slowed metabolism
- decrease in dopamine induced "reward" (satiety) after eating