Role of NO-cGMP pathway in ovine cervical relaxation induced by Erythroxylum caatingae Plowman

Advances in chemistry and bioactivity of the genus Erythroxylum

Erythroxylum P. Browne is the largest and most representative genus of Erythroxylaceae family. It contains approximately 230 species that are mainly distributed in tropical and subtropical regions. Some species in this genus, such as E. monogynum and E. coca, have been used as folk medicines in India or South America for a long history. It is well known that Erythroxylum plants are rich in tropane alkaloids, and the representative member cocaine shows remarkable activity in human central nervous system. However, many other types of active compounds have also been found in Erythroxylum along with the broadening and deepening of phytochemical research. To date, a total of 383 compounds from Erythroxylum have been reported, among which only 186 tropane alkaloids have been reviewed in 2010. In this review, we summarized all remained 197 compounds characterized from 53 Erythroxylum species from 1960 to 2021, which include diterpenes, triterpenes, alkaloids, flavonoids, and other derivates, providing a comprehensive overview of phytoconstituents profile of Erythroxylum plants. In addition, the biological activities of representative phytochemicals and crude extracts were also highlighted.

The Design of a New Catheter for Transcervical Artificial Insemination in Ewes

In ovine species, transcervical artificial insemination (TCAI) is limited by the poor quality of frozen-thawed semen and by the convoluted cervical lumen hampering the passage of inseminating devices. The aim of the study was to test the efficiency of three newly designed catheters with bent tips of 3.5 mm, 5.0 mm or 8.0 mm in terms of reproductive performances (experiment 1) and to compare the results of TCAI with the best performing catheter of experiment 1 to those obtained in ewes submitted to surgical incision of cervical folds (SICF) prior to insemination (experiment 2). The following parameters were assessed: time to pass the cervix; depth of cervical penetration; site of deposition of semen; pregnancy (PR); and lambing rates (LR). The results of experiment 1 indicated that the 5.0 mm tip catheter resulted in deeper and faster TCAI and higher PR and LR compared to 3.5 mm and 8.0 mm tip catheters (p < 0.05). In experiment 2, TCAI with the 5.0 mm catheter did not differ from TCAI after SICF in terms of depth of semen deposition, time to pass the cervix, PR and LR (p < 0.05). In conclusion, the use of a catheter that allowed transcervical uterine deposition of semen without excessive manipulation led to satisfactory pregnancy rates.

Gasotransmitters in pregnancy: from conception to uterine involution

Gasotransmitters are endogenous small gaseous messengers exemplified by nitric oxide (NO), carbon monoxide (CO), and hydrogen sulfide (H2S or sulfide). Gasotransmitters are implicated in myriad physiologic functions including many aspects of reproduction. Our objective was to comprehensively review basic mechanisms and functions of gasotransmitters during pregnancy from conception to uterine involution and highlight future research opportunities. We searched PubMed and Web of Science databases using combinations of keywords nitric oxide, carbon monoxide, sulfide, placenta, uterus, labor, and pregnancy. We included English language publications on human and animal studies from any date through August 2018 and retained basic and translational articles with relevant original findings. All gasotransmitters activate cGMP signaling. NO and sulfide also covalently modify target protein cysteines. Protein kinases and ion channels transduce gasotransmitter signals, and co-expressed gasotransmitters can be synergistic or antagonistic depending on cell type. Gasotransmitters influence tubal transit, placentation, cervical remodeling, and myometrial contractility. NO, CO, and sulfide dilate resistance vessels, suppress inflammation, and relax myometrium to promote uterine quiescence and normal placentation. Cervical remodeling and rupture of fetal membranes coincide with enhanced oxidation and altered gasotransmitter metabolism. Mechanisms mediating cellular and organismal changes in pregnancy due to gasotransmitters are largely unknown. Altered gasotransmitter signaling has been reported for preeclampsia, intrauterine growth restriction, premature rupture of membranes, and preterm labor. However, in most cases specific molecular changes are not yet characterized. Nonclassical signaling pathways and the crosstalk among gasotransmitters are emerging investigation topics.