Summary
The spontaneous contractions of segments of rat portal veins have been examined in vitro under isotonic and isometric conditions. The power density spectra of recorded time series lasting 10–60 min were calculated. The spectra usually consist of harmonic frequency components. Only during shorter periods of analysis (10 min time series) we sometimes found additional non-harmonic components. All frequency components are proportionally shifted by changes of the bath temperature according to an average Q10 of 2.0. Increase of the load decreases the frequency of the contractions.
The results of the spectral analysis, indicating a preponderance of a single source of periodicity, were supported by direct evidence of a pacemaker region. By recording contractions after systematic dissections of the portal vein segment, we found that spontaneous activity is generated at the central end of the segment.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Başar, E., Eroglu, C., Ungan, P.: Time series analysis of guinea-pig tenia coli spontaneous activity. Pflügers Arch.347, 19–25 (1974a)
Başar, E., Eroglu, C., Ungan, P.: An analysis of portal vein spontaneous contractions. Pflügers Arch.352, 135–143 (1974b)
Başar, E., Weiss, C.: Time series analysis of spontaneous fluctuations of the flow in the perfused rat kidney. Pflügers Arch.319, 205–214 (1970)
Bendat, J. S., Piersol, A. G.: Random data analysis and measurement procedures. New York-Toronto: Wiley-Interscience 1971
Brigham, E. O.: The Fast Fourier transform. Englewood Cliffs, N. J.: Prentice-Hall 1974
Golenhofen, K.: Slow rhythms in smooth muscle (minuterhythm). In: Smooth muscle, edited by E. Bülbring, A. F. Brading, A. W. Jones, and T. Tomita. London: Edward Arnold Ltd., 1970
Golenhofen, K., v. Loh, D.: Intrazelluläre Potentialmessungen zur normalen Spontanaktivität der isolierten Portalvene des Meerschweinchens. Pflügers Arch.319, 82–100 (1970)
Hinghofer-Szalkay, H., Kenner, T., Estelberger, W.: The use of spectral analysis for the examination of spontaneous contractions of smooth muscle. Pflügers Arch.359, R65 (1975)
Kenner, T., Ono, K.: Analysis of slow oscillations of arterial flow. Pflügers Arch.331, 347–356 (1972)
Lee, Y. W.: Statistical theory of communication. New York: Wiley & Sons 1960
Moe, G. K.: Evidence for reentry as a mechanism of cardiac arrhythmias. Rev. Physiol. Biochem. Pharmacol.72, 55–81 (1975)
Author information
Authors and Affiliations
Additional information
This work was supported by the Austrian Research Fund
Rights and permissions
About this article
Cite this article
Hinghofer-Szalkay, H., Kenner, T. & Estelberger, W. Spectral analysis of spontaneous contractions of the isolated portal vein of rats. Pflugers Arch. 364, 157–160 (1976). https://doi.org/10.1007/BF00585184
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00585184