BIOGENIC-AMINES IN THE HYPOTHALAMUS OF RATS AFTER DIETHYLDITHIOCARBAMATE OR AIMAX TREATMENT, AN ALTERNATIVE FOR NOREPINEPHRINE DEPLETION

The objective of this study was to determine whether AIMAX ( a dithioc arbamoylhydrazine derivative) is suitable for determining the effects of norepinephrine (NE) depletion on reproduction in domestic animals. Therefore, the effect of AIMAX (n = 6) on concentrations of biogenic a mines in the medial basal hypothalamus (MBH) and anterior hypothalamic area (AHA) of ovariectomized (OVX) rats primed with ovarian steroids was compared to that of diethyldithiocarbamate (DDC; n = 5), a potent dopamine-beta-hydroxylase (DBH) inhibitor, which is chemically similar to AIMAX. Rats that received only ovarian steroids and saline injecti ons served as controls (n = 6). Treatment with DDC resulted in sedatio n and reduced body temperature. In contrast, rats behaved normally aft er AIMAX treatment. AIMAX reduced (P < .05) NE but increased (P < .05) dopamine (DA) concentrations in MBH and AHA compared with controls. S imilar changes in NE and DA concentrations were observed in DDC-treate d rats. However, elevated epinephrine (EPI) levels were measured in MB H and AHA of only DDC-treated rats. Serum LH concentrations were suppr essed (P < .005) in both AIMAX- and DDC-treated rats compared with con trol animals. Because AIMAX, like DDC, suppressed hypothalamic NE cont ent and LH secretion, AIMAX should be useful in studying effects of NE depletion on gonadotropin secretion in domestic animals.