Author/Editor		Sketelj, J; Črne-Finderle, N; Brzin, M
Title		Influence of denervation on the molecular forms of junctional and extrajunctional acetylcholinesterase in fast and slow muscles of the rat
Type		članek
Source		Neurochem Int
Vol. and No.		Letnik 21, št. 3
Publication year		1992
Volume		str. 415-21
Language		eng
Abstract		Acetylcholinesterase (AChE) molecular forms in denervated rat muscles, as revealed by velocity sedimentation in sucrose gradients, were examined from three aspects: possible differences between fast and slow muscles, response ofjunctional vs extrajunctional AChE, and early vs late effects of denervation. In the junctional region, the response of the asymmetric AChE forms to denervation is similar in fast extensor digitorum longus (EDL) and slow soleus (SOL) muscle: (a) specific activity of the A12 form decreases rapidly but some persists throughout and even increases after few weeks ; (b) an early and transient increase of the A4 AChE form lasting for a few weeks may be due to a block in the synthetic process of the A I 2 form. In the extrajunctional regions, major differences with regard to ACh E regulation exist already between the normal EDL and SOL muscle. The extrajunctional asymmetric AChE forms are absent in the EDL because they became completely repressed during the first month after birth, but they persist in the SOL. Differences remain also after denervation and are, therefore, not directly due to different neural stimulation pattems in both muscles : (a) an early but transient increase of the G4 AChE occurs in the denervated EDL but not in the SOL ; (b) no significant extrajunctional activity of the asymmetcic AChE forms reappears in the EDL up till 7 wk after denervation. In the SOL, activity of the asymmetric AChE forms is decreased early after denervation but increases thereafter. Seven weeks after denervation, there is no longer any major difference between the AChE patterns in junctional and extrajunctional regions ofdenervated SOL muscles, and both patterns resemble that in thejunctional region ofdenervated EDL. Postnatal repression of the synthesis of the extrajunctional asymmetric AChE forms in the EDL is, therefore, complete and virtually irreversible while it is incomplete and ceversible in the SOL.(trunc.)
Descriptors		ACETYLCHOLINESTERASE ISOENZYMES MUSCLE DENERVATION MUSCLES NEUROMUSCULAR JUNCTION ACETYLCHOLINESTERASE CENTRIFUGATION, DENSITY GRADIENT ISOENZYMES MUSCLES ORGAN SPECIFICITY RATS RATS, WISTAR ORGAN WEIGHT