Anatomical, histological, and histochemical alterations in portio vaginalis uteri with an evaluation of the vaginal artery vascularity during the luteal and early pregnant stages in domestic buffaloes (Bubalus bubalis)

Abstract

AbstractThe portio-vaginalis uteri (PVU) and its mucus secretion have shown an essential role in conception. A significant endeavour to improve buffaloes' reproductive efficiency is the investigation of their basic reproductive pattern, which provides a reference for applications in breeding and pregnancy. The present study aimed to evaluate the anatomical and histological alterations in PVU regarding to the vaginal artery (VA) hemodynamic at luteal and early pregnant stages in buffalos. Egyptian live buffaloes (n = 16) and fresh genitals (n = 25) of mature buffalo were used. Different luteal and early pregnant stages were macroscopically identified with the shape and mucosal colouration with discharges of the PVU. Histological examination showed a significant difference in area % of alcian blue and periodic acid Schiff positive granules which considered an indication for presence of acidic and neutral mucins respectively in the epithelial cells of PVU mucosa which increased in pregnant stage than in other luteal stages. VA assessment demonstrated an increase in luminal diameter and thickness of tunica muscularis in pregnant stage than other stages (P < 0.05). Middle uterine (MUA) and VA arteries peak velocity point (PSV mm/sec) were elevated (P < 0.05) in pregnant stage, with a marked reduction in both resistance and pulsatility indices (RI and PI), and ratio of systolic /diastolic (S/D). Positive correlation was detected between VA. PSV and, MUA. PSV (r = 0.87), but a negative relation was detected with VA. S/D (r = -0.77), VA.PI (r = -0.89), VA. RI (r = -0.97), MUA. S/D (r = -0.94), MUA. PI (r = -0.85), and MUA. RI (r = -0.88). Doppler indices were negatively corrected with the VA. PSV (r = -0.68). It was concluded that there was a significant alterations in histological features of the cervical PVU at different physiological stages (luteal and early pregnant) in buffalos in relation to the MUA and VA hemodynamic pattern and that hypotheses can be established regarding the female cyclicity that affected by both arteries hemodynamics change.