Author/Editor		Mahne, Blanka
Title		Vezava acetilholinesteraze v motoričnih ploščicah zdravih, denerviranih in paraliziranih mišic podgane
Type		monografija
Place		Ljubljana
Publisher		Medicinska fakulteta
Publication year		1998
Volume		str. 32
Abstract		Background. The asymmetric molecular forms of AChE are probably attached to the basal lamina proteoglycans of the neuromuscular junction (nmj) by ionic interactions involving their "collagenic tail". Nevertheless, recent research on quail muscles showed that most of the AChE in the nmj is more firmly, probably covalently bound. Objective. We will examine the following two hypotheses: 1. The major part of asymmetric AChE molecules in the motor endplates of fast rat muscles is bound with ionic interactions and the rest is bound covalently. 2. The ratio between ionic and covalently bound AChE in the rat nmj is changes in different patophysiological conditions. Methods. A sequential solubilization method was used for studying AChE binding in nmj. Experiments were performed on normal rat extensor digitorum longus (EDL) muscles, as well as on denervated, reinnervated and botulinum toxin paralysed muscles. First, all globular AChE forms were solubilized from the nmj region by a detergent solution. Junctional AChE was further solubilized from the pellets in a high ionic strength medium (1 M LiCI). Finally, a mild proteolytic treatment with papain (0,2 mg/ml) was applied to solubilize the residual junctional AChE. AChE activity was measured with the Ellman's spectrophotometric method. Results. 95% of the AChE activity left over after a detergent treatment in the junctional samples belonged to the junctional AChE. 67 +- 6% of junctional AChE was thereafter solubilized by incubation in a high ionic strength medium; the residual 33% of junctional AChE was extracted only after incubation with papain. In denervated muscles only we could find a small but statistically significant (p<0,03) decrease in the share of AChE which could be solubilized by the high ionic strength medium (58 +- 7%). This share didn't change statistically significantly in reinnervated or paralysed muscle samples in regard to the control muscles. (Abstract truncated at 2000 characters).
Descriptors		MUSCLE, SKELETAL BOTULINUM TOXINS ACETYLCHOLINESTERASE MOTOR ENDPLATE RATS BINDING SITES MUSCLE DENERVATION PAPAIN