Subject(s)
Action Potentials , Myometrium/physiology , Oxytocics/pharmacology , Oxytocin/pharmacology , Animals , Female , Muscle Contraction , Myometrium/drug effects , RatsABSTRACT
Spontaneous bursts of action potential occurring in the ovarian and cervical horn areas as well as in uterine corpus were investigated in non-pregnant rats. The main characteristics of spikes registered simultaneously from the selected active regions under normal conditions - the frequency, amplitude, rise-rate, rise-time and half-width of peaks, were analyzed by complex electrophysiological and morpho-histochemical studies. The ovarian horn area generates high-amplitude spikes that significantly exceed the magnitude of spikes in two other areas. There are small differences between the frequency values in the above-mentioned rhythmogenic areas. The peak rise-rates are the greatest in the ovarian horn area. On the contary, the peak rise-times and the peak half-widths had the smalles values here. It is concluded that there is a significant difference between the values of activity parameters in the ovarian horn area and two other pacemaker areas localized rather close to each other. Analysis of the morphological and histochemical data revealed the greatest aggregation of functionally active cells between the myometrium and serosa in the ovarian horn area. In the cervical horn area and uterine corpus no focal accumulations of these cells were found. Thus, the morphological findings confirmed the electrophysiological results.
Subject(s)
Biological Clocks , Evoked Potentials, Motor , Myometrium/physiology , Animals , Female , RatsABSTRACT
The work is dedicated to the study of the influence of separate rhythmogenic areas on spontaneous activity of the remained areas in the non-pregnant rat myometrium. The main characteristics of pacemaker activity (spike frequency, spike amplitude, duration of burst discharges, summarized period of the active state) of each active region were analyzed under the conditions blocking the influence of others. Parameters of the ovarian horn area did not undergo significant changes unlike the cervical horn area and uterine corpus. The greatest suppression of spike activity parameters was shown in the uterine corpus. It was also revealed that certain activity characteristics (the amplitude of the spikes, duration of burst discharges, summarized period of the active state) are more subjected to change than other parameters. It is concluded that the ovarian horn area may have a controlling role in the interaction of asynchronous pacemaker activities of the rhythmogenic areas in the uterus.
