Contractility of Myometrium Various Parts in Mice

Lytvynenko А. P., Makogon N. V., Yanchiy R. I.

CLINICAL AND EXPERIMENTAL MEDICINE

Scentific article

Traditional organ bath is one of the most popular methods to evaluate the effects of tocolytics and uterotonic agents of myometrial contractility in vitro. Careful analysis of contraction parameters obtained in the organ bath experiments can provide valuable insight into mechanisms underlying the observed tocolytic or uterotonic effects. Phase-plot analyse by using parameter the contractility index (CI) should facilitate the comparison of contractile properties of myometrial samples with different proportions of contractile (smooth muscle) and non-contractile (connective tissue) elements. Myometrium cells have automatic contractile activity represented in the horn and in different parts of the uterine. Published data demonstrate, that pacemaker centers are located in the cervical and ovarian parts of myometrium in mice, but contractile activity in this parts is not investigated in mice. It has been estimated contractility of uterus myometrium cervical (CV) and ovarian (OV) parts with phase-plot analysis in mice. Experiments were carried out in the female СВА mice (18-22 g). Immune complex-mediated failure (ICMF) was induced by the immunization with bovine serum albumin (BSA) once a week (150, 175, 200, 250, 300 mg). Uterine samples were taken from ovarian end (OV) and cervical end (CV) of the uterus and were bathed in Krebs solution. It has been recorded parameters such as: Fmax–amplitude of contraction, mN; W50–contraction duration at 50% amplitude (s), CVmax–positive peak of the first derivative of contraction (maximum rate of contraction, mN/s), RVmax–negative peak of the first derivative of contraction (maximum rate of relaxation, mN/s), T–time interval between CVmax and RVmax (duration of the active state, s), CI –contractility index calculated by multiplying the Fmax by CVmax/RVmax, mN. Results of experiments are statistically processed with program GraphPad Prism 5. 0 (GraphPad Software, San Diego, USA). Checking the normality of the distribution was carried out using the Kolmogorov-Smirnov test and used t-test to compare two means. Contractility index (CI) and rate of relaxation of CP was by 40% and 33% higher compared to OP, but frequency of contraction was by 41% higher in OP vs CP (p<0. 05). ICMF resulted in the decrease of amplitude and CI by 64 і 30% in CV and by 70% and 47% in OV parts of the uterine respectively (р<0,05) as compared with the control values. Experimental systemic immune-complexes-induced failure. reduced the contractile response more in CV than in OV. This can be explained by immune complexes, which are potent inducers of cytokine synthesis and cause vascular damage. OV has strong vascularization and maybe therefore had more inhibition then. Results suggest different contractile activity in uterus myometrium cervical and ovarian parts under physiological conditions and change their contractility in inflammatory processes.

uterus, ovarian part, cervical part, experimental systemic immune-complexes-induced failure

• 1. Беседін О. В. Удосконалення методів лікування хворих на генітальний ендометріоз шляхом корекції нейтрофіло-залежних механізмів: автореф. дис. на здобуття наук. ступеня канд. мед. наук: спец. 14.01.01 «Акушерство та гінекологія» / О. В. Беседін – К., 2000. – 19 с.
• 2. Казарян К. В. Влияние кровоснабжения на характеристики пейсмекерной активности матки крысы / К. В. Казарян, Н. Г. Унанян, Н. Н. Мелконян // НАНА Физиология. – 2012. – Т. 112, №3. – С. 312-319.
• 3. Чоп’як В. В. Системні васкуліти: імунозалежні механізми розвитку та принципи імунотерапії: дис. . . . доктора мед. наук: спец. 14. 01. 29 / Чоп’як Валентина Володимирівна. – Львів, 1998. – 369 с.
• 4. Шелигін О. С. Патогенетичне обгрунтування інтерферонкоригуючої терапії в комплексному лікуванні хронічних за-пальних захворювань придатків матки: автореф. дис. на здобуття наук ступеня канд. мед. наук: спец. 14.01.01 «Аку-шерство та гінекологія» / О. С. Шелигін. – К., 2003. –20 с.
• 5. Aguilar H. N. Physiological pathways and molecular mechanisms regulating uterine contractility / H. N. Aguilar, B. F. Mitchell// Human Reproduction Update. – 2010. – Vol. 16, №6. – Р. 725–744.
• 6. Garfield R. E. Physiology and electrical activity of uterine contractions / R. E. Garfield, W. L. Maner // Seminars in Cell & Developmental Biology. – 2007. – №18. – Р. 289–295.
• 7. Gullam J. E. Phase-plot analysis of the oxytocin effect on human myometrial contractility / J. E. Gullam., A. M. Blanks, S. Thornton, A. Shmygol // Eur. J. Obstet. Gynecol. Reprod. Biol. – 2009. – Vol. 144, Suppl. 1. – P. 20-24.
• 8. Larrubia J. R. Cytokines – their pathogenic and therapeutic role in chronic viral hepatitis / J. R. Larrubia, S. Benito-Martнnez, J. Miquel-Plaza // Rev. Esp. Enferm. Dig. – 2009. – Vol. 101, №5. – P. 343-351.

«Bulletin of problems biology and medicine» Issue 2 part 3 (109), 2014 year, 160-163 pages, index UDK 612. 73: 611. 664