Cholinesterases of rat sympathetic ganglia after immunosympathectomy, decentralization and axotomy.

Abstract

Abstract— Immunosympathectomy was produced in Sprague‐Dawley rats by the subcutaneous injection of 300 units of nerve growth factor (NGF)‐antiserum (1.56 mg of freeze‐dried serum)/g/day for 6 days, the first dose being given 5–8 hr after birth. The immunosympathectomized rats and their control littermates were killed 2½ and 7 months after birth.Ganglionic acetylcholinesterase and pseudocholinesterase activities were measured by an adaption (Kungman, Kungman and Pouszczuk, 1968) of the colorimetric method of Ellman, Courtney, Andres and Featherstone (1961). Following immunosympathectomy the activities of these enzymes decreased significantly in superior cervical, stellate, thoracic chain, cardiac (abdominal), coeliac and superior mesenteric ganglia. The reduction of the acetylcholinesterase activity was greater than expected in a number of sympathetic ganglia, e.g. superior cervical, stellate, coeliac and cardiac ganglia, if one considered that only the postganglionic neurons were affected by immunosympathectomy. The activities of these enzymes were also reduced in the cervical sympathetic trunks from NGF‐antiserum‐treated rats. By means of decentralization and axotomy it was shown that 45 per cent of the total ganglionic acetylcholinesterase activity was associated with the preganglionic and 55 per cent with the postganglionic elements of the superior cervical ganglion from control rats. It was concluded that immunosympathectomy also affects the preganglionic sympathetic neurons. It is not known whether this is a primary effect of the NGF‐antiserum or a secondary effect resulting from the absence of over 90 per cent of the postganglionic sympathetic cell bodies.