Cyclic variations in vaginal thermal conductance in ewes

Effects of natural mating, artificial insemination and intravaginal deposition of raw semen or seminal plasma on vaginal and uterine blood flow in German Holstein cows

AIM

The present study was performed to characterize and compare the perfusion of vaginal and uterine arteries after challenging the reproductive tract of dairy cows via natural mating, artificial insemination (AI), or intravaginal deposition (vaginal fundus) of different biological fluids or a placebo.

MATERIALS AND METHODS

In a double-blind study, six German Holstein cows were administered PGF2α during dioestrus and 48 h later treated with GnRH. Intravaginal or intrauterine treatments were carried out 12 h after GnRH was administered. Animals served as their controls, using a cross-over design with an interval of 14 days between experiments. The experimental animals were allocated to receive the following treatments: natural mating (N), intrauterine artificial insemination (A), intravaginal deposition (vaginal fundus) of 6 mL raw semen (R) or 6 mL seminal plasma (S), and compared to their controls [control 1: 6 mL placebo (P: physiological saline); control 2: no treatment (C)). Corresponding time intervals were chosen for the untreated control oestrus. Blood flow volume (BFV) in the uterine (u) and vaginal (v) arteries ipsilateral to the ovary bearing the preovulatory follicle was determined using transrectal Doppler sonography.

RESULTS

All animals exhibited oestrus and ovulated between 30 and 36 h after GnRH. Transient increases (P < 0.05) in vaginal blood flow occurred between 3 and 12 h following mating as well as 3 to 9 h after deposition of raw semen and seminal plasma, respectively. The most distinct increases (199%) in vBFV occurred 6 h after mating compared to values immediately before mating (= time 0 h). Neither AI nor deposition of a placebo into the vagina affected vBFV (P > 0.05). Only mating and deposition of either raw semen, seminal plasma or AI increased uBFV (P < 0.003). The greatest rise in uBFV occurred after natural mating. Maximum uBFV values were detected 9 h after mating when values were 79% greater (P < 0.05) than at 0 h.

CONCLUSIONS

The natural mating, deposition of raw semen or seminal plasma and conventional AI affect vaginal and/or uterine blood flow to different degrees. The factors responsible for these alterations in blood flow and their effects on fertility remain to be clarified in future studies.

Reproductive characteristics of Holstein heifers fitted with intravaginal temperature transmitters

In this experiment, the safety and feasibility of intravaginal temperature transmittance were tested by radio-telemetry. Each transmitter was positioned non-surgically with a plastic anchor. Heifers wore these transmitters for 107 days with no apparent physical or physiological effect. While the transmitters remained in place, estrous cycles, estrous behavior and fertility following artificial insemination were normal. The data usually revealed a temperature spike of one day on the day of standing heat. Time series analysis enabled the identification of significant temperature departures where the base line was a changing value due to seasonal adjustments. The temperature increase measured at 0645 h was about 0.5 degrees C above the previous five-day average. Absence of 21+/-3-day cyclicity in temperature spikes for two heifers revealed their cystic ovary condition which was later confirmed by rectal palpation. Progesterone and estradiol-17beta patterns were normal for all but one of these heifers. Prostaglandin F2 proportional-induced estrous behavior lacked the expected temperature spike. Affected heifers usually continued to have their temperature spike one more time at a regular estrous interval from the spike prior to PGF2 proportional injection.

Vaginal blood flow during the menstrual cycle

Six nulliparous young women slept 16 to 27 consecutive nights in a clinical research center. Vaginal blood flow was estimated from rates of removal of heat from the vaginal wall by a cooled probe inserted by the women immediately upon awakening. Plasma levels of estradiol, progesterone, luteinizing hormone, and follicle-stimulating hormone were determined. Measured also were vaginal temperature and systolic and diastolic blood pressures. Systematic changes during the cycle were detected for all variables except systolic blood pressure. Rising levels of estradiol during late follicular phase were not correlated significantly with vaginal blood flow rates.

Cold pressor test in women: effect on vaginal blood flow

Vaginal blood flow changes in women were evaluated qualitatively by heat-flow discs mounted on cooled vaginal probe. Statistically significant increases in vaginal blood flow, systolic blood pressure, and pulse rate were found in seven normal subjects during a 4 minute immersion of one hand in ice water.

Bovine vaginal circulation: changes during estrous cycle

Vaginal thermal conductance was measured in 12 heifers and 7 cows with a gradient layer heat flow probe. Values rose for 4 to 5 days prior to day of behavioral estrus (day 0), with a peak on days --2 and --1, and then declined from day 0 to +5. Curves for heifers were higher than those for cows although there was no evidence that they were not parallel. Changes during the cycle appear to result from estrogen-induced alterations in blood flow rate in vaginal tissues.