Effect of teasing, mechanical stimulaton and the intrauterine infusion of saline on uterine contractions in mares

Abstract

Uterine motility may have significance for the transportation of spermatozoa and the elimination of the ejaculate and inflammatory products after mares have been covered. The effect of some of the component stimuli of coitus on uterine contractions was investigated by using M-mode ultrasound. The number, amplitude and duration of the uterine contractions of each uterine horn and of the uterine body were measured in oestrous mares for four minutes before and four minutes after teasing by a stallion, mechanical stimulation of the vagina and cervix, the intrauterine infusion of 80 ml of sterile saline, the intrauterine infusion of 10 ml of sterile saline, the intrauterine infusion of 150 ml of sterile saline, and the transcervical passage of a uterine catheter. Teasing by a stallion did not affect the total number, mean amplitude or mean duration of the uterine contractions. Mechanical stimulation of the vagina and cervix increased the total number of uterine contractions, but did not affect the amplitude or duration of the contractions. The intrauterine infusion of 80 ml of sterile saline resulted in an increase in the total number of contractions and a significant increase in the mean amplitude and the mean duration of the contractions in the uterine horns but not the uterine body. The intrauterine infusion of 10 ml of sterile saline caused a significant decrease in the number of uterine contractions in the uterine horns, but had no effect on the contractions of the uterine body. The infusion of 150 ml of sterile saline reduced the number of contractions in the uterine horns but not the uterine body, and did not affect the mean amplitude and mean duration of the contractions. The transcervical insertion of a catheter reduced the number of contractions in the uterine horns, but did not affect the amplitude or duration of the uterine contractions.

Delayed uterine fluid clearance and reduced uterine perfusion in bitches with endometrial hyperplasia and clinical management with postmating antibiotic

“…It has been proposed that increased uterine contractions at the time of mating function principally to facilitate sperm transport [14,17]. It seems likely, however, that increased myometrial contraction is important both for sperm transport and for the elimination of dead and unwanted sperm, bacteria, and cellular debris [5,6]. The mechanisms promoting mating-induced uterine contractions are unknown, but attractive possibilities include the presence of the male causing oxytocin release [18], tactile stimulation of the reproductive tract and volume of the ejaculate [5,19], and probably the induction of endometrial prostaglandins by constituents of seminal plasma [20] possibly involving complexities of immunoregulatory cytokines.…”

“…The response is characterized by increased uterine contraction, influx of polymorphonuclear neutrophils (PMNs) into the uterine lumen, increased uterine artery blood flow, and uterine vasodilation [2][3][4][5][6]. These responses function to aid the transport of spermatozoa and remove excess and dead spermatozoa, bacteria, and other contaminants that enter the uterus at the time of mating.…”

Effect of Insemination Volume on Uterine Contractions and Inflammatory Response and on Elimination of Semen in the Mare Uterus – Scintigraphic and Ultrasonographic Studies

“…The elimination of semen started simultaneously and the majority was eliminated by 4 h (Katila et al., 2000). An infusion of 80 ml of saline into the uterus caused a significant increase in the amplitude and duration of contractions in the uterine horns, infusions of 10 or 150 ml of saline decreased contractions in the horns (Campbell and England, 2004). Also mechanical stimulation of the vagina and cervix increased the total number of uterine contractions.…”

Saline instillation sonohysterography test after normal baseline transvaginal sonography results in infertility patients. Is it justified?

“…Another possible explanation is that the catheter caused stimulation of the myometrium leading to myometrial contraction, observed as abnormal bulging of the cavity and interpreted as either polyp or fibroid. Previous studies have shown that physical stimulation of the uterus caused by catheter insertion or saline instillation into the endometrial cavity may lead to myometrial contractions [13,14].…”