Inhibition by an ergoline derivative (dopaminergic agonist) of oestradiol-induced adenohypophyseal growth and of the...

The increase in adenohypophyseal weight and the decrease in the ascorbic acid concentration in the hypothalamus of rats injected i.m. twice a week with oestradiol benzoate as an aqueous microcrystal suspension in doses of 2.65 mumol (1 mg) was completely (HAA) or almost completely (adenohypophyseal weight) inhibited by the simultaneous administration of the ergoline derivative D-6-methyl-8-ergoline-(1)-yl acetic acid amide (Deprenon SPOFA) in the diet in daily doses of 0.28 mumol (200 micrograms) per rat. The functional significance of HAA in dopaminergic modulation of oestrogen-induced adenohypophyseal growth is discussed, with special reference to the possible function of HAA as a dopamine-beta-hydroxylase cofactor.