Evaluating aminophylline and progesterone combination treatment to modulate contractility and labor-related proteins in pregnant human myometrial tissues

A randomised feasibility tolerability study of aminophylline for the prevention of preterm labour

BACKGROUND

Progesterone is known to maintain uterine quiescence as pregnancy advances. Recently, its efficacy in preventing preterm birth has been questioned prompting a search for an alternative treatment option. Cyclic AMP has been shown invitro to act in synergy with progesterone to maintain uterine quiescence.

METHODS

We undertook an open label randomised feasibility study to test the hypothesis that the addition of aminophylline to the standard of care (SoC) is acceptable and can be tolerated in pregnant women at high risk of spontaneous preterm labour (sPTL). Women at high risk of sPTL, who met the inclusion criteria were invited to participate and randomised to receive the SoC (progesterone alone, n = 33) or treatment with the SoC and aminophylline (n = 37). The main outcome measure was to assess the how many women at high-risk of sPTL tolerated and continued to take aminophylline. Data were analysed using Graphpad Prism 8.0c (Graphpad Software, San Diego, CA, USA).

RESULTS

We found that of the addition of aminophylline was well tolerated in 30 of the 33 (91%) of women who continued in the combined arm, without any additional adverse maternal or fetal outcomes. 58% of eligible women agreed to participate in the study. The compliance rate was high at 99.42% +-0.82%. 67% of the women completed the post study questionnaire and all stated their willingness to take aminophylline if it were offered routinely for the prevention of sPTL.

CONCLUSIONS

The addition of aminophylline to the SoC is acceptable to women at high-risk of sPTL confirming that a randomised trial of aminophylline to reduce preterm delivery in women at high-risk of PTL is feasible.

TRIAL REGISTRATION

Clinical trial gov NCT03152942. Date of full registration: 15/5/2017. https://clinicaltrials.gov/ct2/show/NCT03152942?cond=NCT03152942%26;draw=2%26;rank=1 .

How Is Arachidonic Acid Metabolism in the Uterus Connected with the Immune Status of Red Deer Females (Cervus elaphus L.) in Different Reproductive Stages?

Reproductive and condition parameters' dependency on immune status in seasonally reproducing ruminants such as red deer have not been outlined to date. We determined T and B blood lymphocytes; the concentration of IgG, cAMP, haptoglobulin, and 6-keto-PGF1α in blood plasma; and the mRNA and protein expression of PG endoperoxide synthase 2, 5-lipoxygenase, PGE2 synthase (PGES), PGF2α synthase (PGFS), PGI2 synthase (PGIS), leukotriene (LT)A4 hydrolase, and LTC4 synthase (LTC4S) in the uterine endo- and myometrium, on the 4th (N = 7) and 13th (N = 8) days of the estrous cycle, in anestrus (N = 6) and pregnancy (N = 8) in hinds. An increase in CD4+ T regulatory lymphocyte percentage during the estrous cycle and anestrus compared with pregnancy was recorded; the opposite effect was observed for CD21+ B cells (p < 0.05). cAMP and haptoglobin concentration were elevated during the cycle, as was IgG on the fourth day of the cycle, whereas 6-keto-PGF1α concentration was the highest in pregnancy, and the nearest in anestrus similarly were LTC4S, PGES, PGFS, and PGIS protein expression in the endometrium (p < 0.05). We showed an interaction between the immune system activation and AA-metabolite production in the uterus throughout different reproductive stages. IgG, cAMP, haptoglobin, and 6-keto-PGF1α concentrations are valuable candidates for markers of reproductive status in hinds. The results help expand our knowledge of the mechanisms underlying seasonal reproduction in ruminants.

Assessing the Potency of the Novel Tocolytics 2-APB, Glycyl-H-1152, and HC-067047 in Pregnant Human Myometrium

The intracellular signaling pathways that regulate myometrial contractions can be targeted by drugs for tocolysis. The agents, 2-APB, glycyl-H-1152, and HC-067047, have been identified as inhibitors of uterine contractility and may have tocolytic potential. However, the contraction-blocking potency of these novel tocolytics was yet to be comprehensively assessed and compared to agents that have seen greater scrutiny, such as the phosphodiesterase inhibitors, aminophylline and rolipram, or the clinically used tocolytics, nifedipine and indomethacin. We determined the IC₅₀ concentrations (inhibit 50% of baseline contractility) for 2-APB, glycyl-H-1152, HC-067047, aminophylline, rolipram, nifedipine, and indomethacin against spontaneous ex vivo contractions in pregnant human myometrium, and then compared their tocolytic potency. Myometrial strips obtained from term, not-in-labor women, were treated with cumulative concentrations of the contraction-blocking agents. Comprehensive dose-response curves were generated. The IC₅₀ concentrations were 53 µM for 2-APB, 18.2 µM for glycyl-H-1152, 48 µM for HC-067047, 318.5 µM for aminophylline, 4.3 µM for rolipram, 10 nM for nifedipine, and 59.5 µM for indomethacin. A single treatment with each drug at the determined IC₅₀ concentration was confirmed to reduce contraction performance (AUC) by approximately 50%. Of the three novel tocolytics examined, glycyl-H-1152 was the most potent inhibitor. However, of all the drugs examined, the overall order of contraction-blocking potency in decreasing order was nifedipine > rolipram > glycyl-H-1152 > HC-067047 > 2-APB > indomethacin > aminophylline. These data provide greater insight into the contraction-blocking properties of some novel tocolytics, with glycyl-H-1152, in particular, emerging as a potential novel tocolytic for preventing preterm birth.