The primary goal of this study was to elucidate variations in the structure of ovarian vasculature through light and electron microscopy during breeding (BS) and non-breeding season (NBS) in female dromedaries. Tissues samples of ovarian artery (OA) and ovarian vein (OV) from ten adult female dromedaries during BS and NBS were collected after the slaughter of animals. Histological analysis was done to calculate different characteristics of OA and OV through Hematoxylin & Eosin, Masson’s trichrome and Weigert’s elastin staining. Ultrastructural changes were evaluated by transmission (TEM) and scanning electron microscopy (SEM). Blood was collected to determine the serum levels of estrogen and progesterone. Statistical analysis revealed that the diameter of OA was recorded significantly (P<0.05) larger and fiber content (collagen, elastic) was found significantly (P<0.05) lower in the OA during BS than that of NBS. The area of intra-mural venules (IMV) in unit area observed in OA was significantly (P<0.05) higher during BS compared to NBS. Ultra-structurally, IMVs were simple endothelial tubes surrounded by loose collagenous tissue. The endotheliocytes contained small cytoplasmic vacuoles which showed significantly (P<0.05) larger diameter in OA during BS compared to NBS. The diameter of OA and serum estrogen level showed a strong positive correlation (r=0.68) during BS in contrast to the serum progesterone level which was found inversely correlated (r=-0.34). It is conceivable from the data that the structural organization of OA and OV behaves differently according to the breeding season in the female dromedaries. These changes are directly related to the changes in the ovarian hormonal transport, locally and systemically. To produce paracrine effects, IMV in the OA and cytoplasmic vacuoles in the endothelial cell may be purposed as a site of the transport.

To Cite This Article: Usman M, Qureshi AS, Shahid RU, Rahman SU, 2021. Scanning and transmission electron microscopic changes in the ovarian vasculature of female dromedaries in relation to breeding season and hormonal profile. Pak Vet J, 41(2): 215-220. http://dx.doi.org/10.29261/pakvetj/2020.107