Microvascularization of corpus luteum of bovine treated with equine chorionic gonadotropin

Abstract

This study aimed to evaluate the morphological changes in microvascular density and corpus luteum (CL) vascularization in cows treated with eCG during stimulatory and superovulatory protocols. Sixteen cows were synchronized and divided into three groups: control (n = 6), stimulated (n = 4) and superovulated (n =6), one was submitted to estrous synchronization (ES) and received no eCG (control), and those that were submitted to ES and received eCG before or after follicular deviation (superovulation and stimulation of the dominant follicle, respectively). Ovulation was synchronized using a progesterone device-based protocol. After six days of ovulation, the cows were slaughtered and the ovaries and CL were collected. The CLs were processed and photomicrographs were taken under light microscopy to assess the vascular volume density (Vv) by stereology, and scanning electron microscopy (SEM) was used to perform ultrastructural analysis of the microvasculature. The Vv in stimulated and superovulated cows significantly increased (P ≤ 0.0001) when compared to control, indicating that the eCG is able to induce angiogenic activity in bovine CL. However, no significant differences were observed between stimulated and superovulated cows. The SEM demonstrated ratings indicative of angiogenesis, marked by several button-shaped projections in the capillaries, and the presence of more dilated capillaries in CL treated with eCG. These morphological findings are evidence of an angiogenic effect of the eCG treatment in CL of cows.

The effectiveness of low‐dose of eCG in timed AI Nelore (Bos indicus) heifers

“…Differential expression of these genes has been proposed as a crucial factor leading to increased CL volume and improved progesterone production by luteal cells (Fátima, Baruselli, et al., 2012). Moreover, eCG enhanced the density and volume of both small and large luteal cells and mitochondrial density (Rigoglio et al., 2013) and increased the vascular density of the CL (Moura et al., 2015). By these mechanisms, eCG treatment induces functional and morphological changes in the CL, such as the increase in volume and elevation of plasmatic progesterone concentrations (Baruselli et al., 2023).…”

Use of new recombinant proteins for ovarian stimulation in ruminants

“…In another study, we analyzed by microarray the effects of stimulatory treatments using eCG on the luteal gene expression profile. It has been observed that eCG causes changes in the expression of multiple genes, particularly those related to P4 synthesis, metabolism, cell differentiation, proliferation, and angiogenesis (Fátima et al, 2013;Moura et al, 2015). Moreover, among the differentially expressed genes after eCG treatment, many were involved in lipid biosynthesis and progesterone production, such as PPARG, STAR, prolactin receptors, and follistatin (Fátima et al, 2013).…”