Abstract

Introduction

Materials & Methods

Results

Discussion & Conclusion

References

Discussion
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* smooth muscle cell cultures can be established from small explants of different parts of the LUT

* adhesion of the explants is best on collagen coated plastic dishes

* cultures are suitable for physiological experiments from 6 to 21 DIV

* calcium-imaging experiments showed that cells taken from different parts of the LUT keep in part their specific transmitter profile.

As has been shown with autoradiographical, biochemical and immunocytochemical methods, cholinergic, adrenergic and NANC transmitter receptors are expressed in the smooth muscle cells of the LUT of man and several animal species (Edvardsen and Setekleiv, 1968; Creed, 1971; Anderson, 1993; Tainio, 1993; Walden et al., 1997). Studies of the contractile properties of detrusor and prostate indicate, that alterations in the signal transduction system and / or of the contractile aparatus itself might be responsible for dysfunctions like instabillity of the bladder (Brading, 1997; Fry und Wu, 1998). Analysis of signal transduction at a cellular level are necessary to better understand patho-mechanisms of myogenic dysfunctions and to develop new therapy options.

Most of those experiments are done with freshly isolated smooth muscle cells (Kloeckner und Isenberg, 1985; Eckert et al., 1995; Wammack et al., 1995). One disadvantage of this approach is, that the number of cells which can be examined is quite small and it is hard to preserve cells by cryoconservation for further experiments. There are few reports on the use of cell cultures for electrophysiology and calcium-imaging of LUT smooth muscle cells (Harriss DR, 1995; Baskin et al., 1993). The purpose of our experiments was to establish a cell culture system to study smooth muscle cells from different regions - i. e. from different smooth muscles - of the LUT. We have been able to demonstrate, that cultured smooth muscle cells even keep their typical profile of transmitter receptors and thus it seems possible to develop a test system for pharmacological screening of anticholinergica and other neuroactive substances.

In our experiments it also proved, that guinea-pig is a suitable animal-model for comparative studies of the LUT. These findings are in agreement with our anatomical studies (Neuhaus and Dorschner, unpublished) which demonstrated comparable muscular structures in guinea-pig and human LUT. Further experiments are in progress to analyse receptors and calcium release mechanisms involved in the response upon neurotransmitter stimulation.

Acknowledgements: The authors want to thank Ms. R. Hieke and Ms. M. Dettmer for their excellent technical support.

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