Acetylcholine and related enzymes in the neural lobe and anterior hypothalamus of the rabbit

Abstract

SUMMARY1. Acetylcholine (ACh), cholinesterases and choline acetyltransferase (choline acetylase) were estimated in the neural lobe and hypothalamus of the adult male rabbit. Acetylcholine was also estimated in the neural lobes and hypothalami of some other mammals.2. Acetylcholine-like activity was measured by bio-assay using the leech dorsal muscle preparation.3. Characterization experiments indicated that about 90 % of the activity measured was due to acetylcholine.4. Mean acetylcholine content in the neural lobe of the rabbit, after extraction with perchloric acid, was 4-38 + 0-98,g/g fresh tissue, and 4-87 + 1-53 /tg/g in the hypothalamus.5. Acetylcholine was also found to be present, in comparable concentrations, in the neural lobe of man and in the neural lobes and hypothalami of ox, rat and hedgehog.6. Acetylcholinesterase, present in the neural lobe and hypothalamus of the rabbit, hydrolysed 1-74 + 0-11 It-moles of substrate/min/g and 3-78 + 0*60 It-moles substrate/min/g fresh tissue respectively.

Preferential release of newly synthesized 3H‐acetylcholine from rat cerebral cortex slices in vitro

“…Important losses probably did not occur because the cholinesterases were completely inhibited. The efficiency of the extraction was probably good since extraction with perchloric acid according to the method of Morris, Bull & Hebb (1965) which has been reported to be highly efficient for the extraction of ACh from fresh brain tissue (Lederis & Livingston, 1969) does not give higher yields of ACh from cortex slices treated with soman than the method used in the present experiments (Polak, unpublished experiments).…”

The Mammalian Pars Intermedia: A Review of Its Structure and Function

“…Aminergic neurones have been demonstrated in the pars intermedia ) and since hypothalamic cholinergic fibres have been described in the pituitary stalk and pars nervosa (Lederis, 1967;Lederis & Livingston, 1969;Thorn, 1970), the possibility of cholinergic systems to the pars intermedia should not be over¬ looked. Vincent & Kumar (1969) have discussed the possible roles of the different forms of nerve fibre (the so-called Type A, 'peptidergic'; Type B, 'aminergic'; and Type C, 'cholinergic') in the pars intermedia of various vertebrates.…”

Noradrenaline and acetylcholine responses of supraoptic neurosecretory cells

“…Both ACh and NA and their appropriate enzymes are present in large amounts in the supraoptic nucleus (Feldberg & Vogt, 1948; Koelle, 1954;Abrahams, Koelle & Smart, 1957;Carlsson, Falck & Hillarp, 1962;Uemura, 1965;Shute & Lewis, 1966;Iijima, Shantha & Bourne, 1967;Rechardt, 1969;Lederis & Livingston, 1969). Furthermore, the injection of diisopropylfluorophosphate (an anticholinesterase agent) into the supraoptic nucleus causes the release of ADH, presumably by increasing the endogenous level of ACh in the nucleus (Duke, Pickford & Watt, 1950).…”