Identificação imuno-histoquímica de VEGF e IGF-1 em ovários de cadelas no anestro e estro

Quantification of multi-oocyte follicles in ovaries of bitches

ABSTRACT The objective of this study was to quantify the number and frequency of monocyte (MnOF) and multi-oocyte (MtOF) follicles in ovaries of bitches subjected to ovary salpingohysterectomy (OSH). Right and left ovaries of 38 bitches were collected after OSH, prepared, and a histological analysis was carried out. The ovaries were subjected to surface and deep histological cuts; the follicles were classified, and the number of follicles and cumulus oophorus complexes (COC) per follicle were quantified for each histological cut. MnOF and MtOF were found in all ovaries, at different developmental stages; primary follicles were grouped in the ovarian cortex, and follicles at other follicular stages presented a random distribution. MtOF containing two, three, four, or more COC were found in the ovaries of bitches, with a decreasing frequency trend, according to the number of COC in the MtOF. The effect of the age, number of estrus, estrus interval, and number of progenies per delivery was not significant for the number and frequency of MtOF in the ovaries of the bitches, whereas the size, number of pregnancies, use and number of contraceptive applications had some effect on the number and frequency of MtOF in the ovaries of the bitches.

"Immunolocalization and effect of low concentrations of Insulin like growth factor-1 (IGF-1) in the canine ovary"

Insulin like growth factor‐1 (IGF‐1) plays an important role in the regulation of ovarian function. Despite its extensive study in several species, there is a paucity of information about IGF‐1`s function and localization in the canine ovary. The aim of the present study was to assess the effect of IGF‐1 on oocyte nuclear maturation and to immunolocalize the IGF‐1 and its receptor (IGF‐1R) in the ovary. Cumulus‐oocyte complexes (COCs) were obtained from 34 bitches. The COCs from each bitch were incubated in TCM 199‐HEPES in the absence (n = 199) or presence (n = 204) of 100 ng/ml IGF‐1 for 96 hr at 38ºC in 5% CO₂, stained and evaluated for nuclear maturation by fluorescence microscopy. The results showed that the addition of IGF‐1 did not have an effect (p ˃ 0.05) on the nuclear maturation under these conditions. The immunohistochemical study revealed nuclear and cytoplasmic staining for IGF‐1 and IGF‐1R, respectively. Both were localized in all ovarian structures including the corpus luteum, but not in the granulosa cells from primordial follicles. In addition, IGF‐1 was not localized in the oocytes in tertiary follicles. The results obtained show the presence of IGF‐1 through the stages of follicular growth and in the corpus luteum of the canine ovary. However, its role on oocyte nuclear maturation could not be demonstrated.