Suppression of prolactin and growth hormone responses to 2-deoxy-D-glucose-induced glucoprivation by mazindol in humans.
Glucoprivation induced by 2-deoxy-D-glucose (2DG) 20 min infusions (50 mg/kg) increases growth hormone (GH) and prolactin (PRL) levels in humans. To determine if mazindol, a potent dopamine (DA) and norepinephrine (NE) reuptake blocking agent, might affect basal and stimulated GH and PRL levels in healthy male and female volunteers, mazindol (1 mg, TID,po) or placebo were administered for one week before 2DG infusions. Plasma samples for glucose, epinephrine (E), NE, PRL, and GH were collected before and after 2DG infusions. During placebo and mazindol therapy, basal values (ng/ml) did not differ for either PRL (8.8 +/- 1.6 versus 8.9 +/- 1.5 in females and 8.3 +/- 0.9 versus 7.7 +/- 0.6 in males) or GH (1.6 versus 1.7 +/- 0.1 in males and 6.6 +/- 3.3 versus 7.0 +/- 2.6 in females). Peak stimulated PRL levels were greater in females than in males (97.1 +/- 26.2 versus 21.4 +/- 5.3 ng/ml, p less than 0.05) while peak stimulated GH levels were greater in males than in females (28.2 +/- 1.7 versus 7.0 +/- 2.0 ng/ml, p less than 0.05). Mazindol therapy reduced 2DG-stimulated PRL responses (ng/ml) from 97.1 +/- 26.2 to 44.4 +/- 25.3 (p less than 0.0125) and from 21.4 +/- 5.3 to 13.6 +/- 3.4 (p less than 0.025) in females and males respectively, and GH responses (ng/ml) from 28.2 +/- 1.7 to 13.1 +/- 3.8 (p less than 0.05) and from 10.2 +/- 2.0 to 3.4 +/- 0.1 (p less than 0.05) in males and females respectively, but baseline PRL and GH levels were unaffected. A 50%-60% overall suppression of stimulated GH and PRL levels by mazindol was not significantly different between sexes and not consistently related to elevations in plasma glucose or E although stimulated plasma NE levels were higher during mazindol therapy.
D001786:Blood Glucose / Q000378:metabolism; D003837:Deoxy Sugars; D003847:Deoxyglucose; D004837:Epinephrine / Q000097:blood; D005260:Female; D013006:Growth Hormone / Q000097:blood*; D006801:Humans; D007211:Indoles; D007700:Kinetics; D008297:Male; D008454:Mazindol; D009638:Norepinephrine / Q000097:blood; D010919:Placebos; D011388:Prolactin / Q000097:blood*; D012737:Sex Factors
D001786:Blood Glucose; D003837:Deoxy Sugars; D007211:Indoles; D010919:Placebos; D011388:Prolactin; D013006:Growth Hormone; D003847:Deoxyglucose; D008454:Mazindol; D009638:Norepinephrine; D004837:Epinephrine