1. The rise in blood pressure and the eyelid contractions elicited by electrical stimulation of the posterior hypothalamus in anaesthetized @entity35 were studied for the assessment of drug effects on the sympathetic system. They were compared with the @entity1063 pressor effect and eyelid responses to cervical sympathetic nerve stimulation.2. @entity5521 caused a similar reduction of the pressor responses induced by hypothalamic stimulation and by @entity1063 . It also reduced the eyelid contractions elicited by central and by peripheral electrical stimulation.3. @entity2997 caused an immediate inhibition of the pressor response to hypothalamic stimulation, while it potentiated @entity1063 effects. Eyelid contractions elicited both by central and by peripheral electrical stimulation were inhibited.4. @entity2644 inhibited the pressor responses both to hypothalamic stimulation and to @entity1063 , but it caused a much greater reduction in the centrally evoked eyelid responses than in those due to peripheral stimulation.5. @entity3175 caused a reduction of sympathetic responses to central stimulation but not to peripherally elicited responses.6. In unanaesthetized @entity35 the rise in blood pressure induced by hypothalamic stimulation was accompanied by @entity2915 culminating in a flight reaction. In contrast to the pressor effect, which was reduced by all four of the above-mentioned drugs, the flight reaction was not affected by @entity5521 and @entity2997 and only delayed by @entity2644 and @entity3175 at dose levels which impaired the spontaneous locomotor activity.

Pharmacological modifications of sympathetic responses elicited by hypothalamic stimulation in the XXXX .

@entity2997 :: ('MESH:D006145', 'Chemical') :: ['guanethidine', 'Guanethidine'] @entity3175 :: ('MESH:D003975', 'Chemical') :: ['Diazepam', 'diazepam'] @entity5521 :: ('MESH:D010646', 'Chemical') :: ['Phentolamine', 'phentolamine'] @entity2644 :: ('MESH:D002746', 'Chemical') :: ['chlorpromazine', 'Chlorpromazine'] @entity2915 :: ('MESH:D006948', 'Disease') :: ['increased locomotor activity'] @entity35 :: ('10116', 'Species') :: ['rats'] @entity1063 :: ('MESH:D009638', 'Chemical') :: ['noradrenaline']
@entity35 :: (10116,Species) :: ['rat']
