An assessment of sympathetic function in isolated tissues from mice given nerve-growth-factor antiserum and 6-hydroxydopamine.

1. Experiments were done on isolated tissues from mice injected with 0.9% w/v NaCl solution (saline), 6-hydroxydopamine (6-OHDA), nerve-growth-factor antiserum (NGF-As) or a combination of these agents (NGF-As+6-OHDA).2. Fluorescence histochemistry of vasa deferentia showed clear differences between each of the treatments but no such distinction was possible in cardiac ventricle or intestine.3. Compared with controls, the chronotropic responses of atria to field stimulation were reduced by all three treatments in the order NGF-As<6-OHDA<NGF-As+6-OHDA. Supersensitivity to noradrenaline occurred in atria from all treated groups.4. In contrast, vasa deferentia from NGF-As-treated mice responded almost identically with controls to both field stimulation and to exogenous noradrenaline. Considerable functional impairment and noradrenaline supersensitivity were obvious in both the 6-OHDA and the NGF-As+6-OHDA groups but no distinction could be made between them.5. The relaxation of superfused ileum following nerve stimulation was reduced in the NGF-As group, whilst preparations from the two groups given 6-OHDA usually gave a motor response which was blocked by atropine.6. None of the treatments employed in these experiments caused complete sympathectomy although 6-OHDA alone or in combination with NGF-As produced a more pronounced effect than NGF-As alone and the relative ineffectiveness of the latter is discussed. The implications of the motor response after 6-OHDA in ileum when the nerves were stimulated is considered in the light of the cholinergic link hypothesis.