
TY  - JOUR
A1  - Smythe, GA 
A1  - W Duncan, M 
A1  - Bradshaw, JE 
A1  - Nicholson, MV 
T1  - Effects of 6-Methoxy-l,2,3,4-tetrahydro-b-carboline and Yohimbine on Hypothalamic Monoamine Status and Pituitary Hormone Release in the Rat
JF  - Australian Journal of Biological Sciences
JO  - Aust. Jnl. Of Bio. Sci.
Y1  - 1983
VL  - 36
IS  - 4
SP  - 379
EP  - 386
KW  - 
UR  - https://doi.org/10.1071/BI9830379 
N2  - Shortly after administration of 6-methoxy-1,2,3,4-tetrahydro-ft-carboline (6-MeOTHBC) and yohimbine to normal or hypothyroid rats [the latter exhibiting chronically elevated levels of serotonin (5-HT) neuronal activity in the hypothalamus] there was a highly significant increase in hypothalamic noradrenaline (NA) activity and in ACTH release concomittant with a reduction in hypothalamic 5-HT activity (P< 0'01) and in growth hormone (GH) (P<O'01) and in thyroid stimulating hormone (TSH) (P< 0'01) release from the pituitary. Both compounds caused an increase in hypothalamic dopamine (DA) metabolism and in pituitary prolactin (PRL) release in normal rats (P<0'01) but only yohimbine exerted this action in hypothyroid rats. Lower doses of 6-MeOTHBC exerted a relatively specific effect in hypothyroid rats, reducing (P< 0·01) 5-HT neuronal activity in parallel with pituitary TSH secretion (P<0·05). While gross effects of 6-MeOTHBC and yohimbine were similar with respect to their effects on NA and 5-HT status in the hypothalamus, there were quantitative differences. 6-MeOTHBC always caused a greater decrease in 5-HT turnover and a lesser increase in NA turnover than did yohimbine. 
ER  -

