Morphological features and vascularization study of caprine cyclic corpus luteum

Abstract

RESUMO.-[Características morfológicas e estudo da vascularização do corpo lúteo cíclico de cabras ao longo do ciclo estral.] O corpo lúteo é uma glândula endócrina temporária que regula tanto o ciclo estral quanto a prenhez, apresentando extrema dependência de aporte sanguíneo adequado. Objetivaram-se avaliar mudanças morfométricas dos ovários e densidade vascular (DV) dos corpos lúteos (CL) de cabras ao longo do ciclo estral (AOLC). Vinte animais foram submetidos ao tratamento para indução/sincronização do estro, usando esponjas intravaginais com Corpus luteum is a temporary endocrine gland that regulates either the estrous cycle and pregnancy. It presents extreme dependency on the adequate blood supply. This work aims to evaluate goat corpus luteum (CL) vascular density (VD) over the estrous cycle. For that purpose, 20 females were submitted to estrus synchronization/ovulation treatment using a medroxyprogesterone intra-vaginal sponge as well as intramuscular (IM) application of cloprostenol and equine chorionic gonadotrophine (eCG). After sponge removal, estrus was identified at about 72hs. Once treatment was over, female goats were then subdivided into 4 groups (n=5 each) and slaughtered on days 2, 12, 16 and 22 after ovulation (p.o). Ovaries were collected, withdrawn and weighted. CL and ovaries had size and area recorded. Blood samples were collected and the plasma progesterone (P4) was measured through RIA commercial kits. The VD was 24.42±6.66, 36.26±5.61, 8.59±2.2 and 3.97±1.12 vessels/mm 2 for days 2, 12, 16 and 22 p.o, respectively. Progesterone plasma concentrations were 0.49±0.08, 2.63±0.66, 0.61±0.14 and 0.22±0.04ng/ml for days 2, 12, 16 e 22 p.o, respectively. Studied parameters were affected by the estrous cycle phase. Values greater than 12 p.o were observed. In the present work we observed that ovulation occurred predominantly in the right ovary (70% of the animals), which in turn presented bigger measures than the contra lateral one. There is a meaningful relationship between the weight and size of the ovary and these of CL (r=0.87, r=0.70, respectively, p<0.05). It is possible to conclude that morphology of goat's ovaries and plasma progesterone concentration changed according to estrous cycle stages. We propose these parameters can be used as indicators of CL functional activity.

Morphology and vascularization of the corpus luteum of peccaries (Pecari tajacu, Linnaeus, 1758) throughout the estrous cycle

“…The decrease in P 4 secretion coincided with a reduction of vascular density on day 16 p.o. Similar results were previously provided for goats, cows and buffaloes (Moura et al, 2003;Papa et al, 2007;Miranda-Moura et al, 2010).…”

“…Statistical analysis revealed that weight, length and width of the corpora lutea were also significantly affected by the estrous cycle phase (P<0.001, Table 3). The above result has been expected since the measurements of the organ frequently estimate the stage of the estrous cycle and the luteal functional activity (Ferreria-Dias et al, 2006;Papa et al, 2007;Nascimento et al, 2003;Miranda-Moura et al, 2010). Current rates were once again higher when compared to the diameter and volume of peccaries´ CL described by Mayor et al (2006a), perhaps due to the difference in the diet's energy rates taken by the animals favoring weight gain and thus their reproduction.…”

“…Vascular density is often assessed in the corpus luteum since it is a gland whose function is closely related to vascularization (Gaytan et al, 1999). In spite of studies on the variations in lutein vascular density during the estrous cycle in other species (Moura et al, 2003;Miranda-Moura et al, 2010), the current analysis on the peccary features is the first investigation and is a pioneering endeavor.…”

Histological Feature of Ovarian Structures Throughout the Reproductive Cycle in Alpine Goats (Capra Hircus)

“…Curiously we have not found corpora albicantia in any of the ovary examined. CA are described as white fibrous tissue that replaces the regressing corpus luteum approximately equal to 3-4 mm in diameter in ewes (28) and are also detected in goats (29). We can speculate that these structures are made evident in older goats after at least one anestrus phase.…”

Quantitative Evaluation of the Vasculature Supplying the Oviduct in Pre‐Pubertal and Sexually Mature Sows

“…A sequence of capillary remodelation has been proposed in the follicle capillary network so that, in preovulatory follicles angiogenesis is commonly initiated by the outward growth of endothelial cells from preexisting vessels (budding), which is followed by sprouting (elongation) and dilation of the incipient new vessel. In contrast, in late periovulatory follicles infolding (intussusception) and duplication or splitting of preexisting vessels followed by sinusoidalization leads to a rapid neovascularization of the ovulated follicle so as to sustain the nutrition and function of the developing corpus luteum (Macchiarelli et al, ; Martelli et al, ; Miranda‐Moura et al, ; Mauro et al ). Similarly, in the uterus an effective neovascularization is observed during the endometrial proliferation occurring in the luteal phase of the estrous cycle or in the placenta (Rogers and Abberton, ; Huppertz and Peeters, ).…”