Recent studies have shown that molecules, such as leptin, orexins and cannabinoids, are in general spread ubiquitously in the body very often involving anatomical structures not functionally related to appetite control [1, 2, 3]. The female genital tract is very often implicated, and this has led to the hypothesis that the same molecules are involved in its functional Control representing a point of contact between the animal's nutritional status and its functionality. In this context two proteic hormones, ghrelin and apelin, have been already highlighted in the ovary of some animal species [4, 5, 6] suggesting involvement in its functional control. The aim of the present work was to highlight the presence and the localization of ghrelin, apelin and their receptors in the ovary of non-pregnant bitches, with the purpose of providing data that may be useful in fully understanding the functionality of this organ. The experiment was conducted using six mixed-breed dogs, admitted to the day-hospital service at the Veterinary Teaching Hospital of the University of Perugia and regularly subjected to the ovario-hysterectomy by spaying. The ovaries were removed and immediately fixed in 4% formaldehyde solution and subsequently processed for embedding in paraffin. The immunohistochemical reactions were visualized on 5 μm serial sections, using anti-Apelin (ab59469), anti-APJ receptor (ab140508), anti-Ghrelin (ab129383) and anti-Ghrelin receptor (ab188986) polyclonal antibodies, avidin-biotincomplex and DAB as the chromogen. All the sections were counter-stained with haematoxylin. Sections in which the primary antibodies were omitted, were used as controls for unspecific staining. The immunohistochemical study showed a strong positivity for apelin, ghrelin and their receptors in some of the ovarian structures. In particular, a positive immuno-reaction for apelin and its receptor and for the ghrelin receptor seemed to be evident in the corpora lutea with a peculiar localization in some of the luteal cells. On the contrary, regarding ghrelin, a positive reaction for this molecule was evident within the wall of small arteries localized both inside the corpora lutea and in the connectival tissue. In general, the immuno-positive reaction seemed to affect only the cellular cytoplasm and was not observed in other ovarian structures or in the sections utilized as negative controls. Due to the presence of these molecules and their receptors in some of the luteal cells and within the wall of small arteries in corpora lutea and in connectival tissue, we can hypothesize that apelin and ghrelin might influence the functionality of ovarian structures where they are localized, suggesting the existence of autocrine/paracrine mechanisms of regulation. 1) Balogh et al., Reprod. Biol. Endocrinol. 8, 1-12, 2015 2) Liguori et al., Anat. Histol. Embryol. 43, 42-47, 2014 3) Hutch et al., Neuroscience. 300, 539-553, 2015 4) Du et al., Domest. Anim. Endocrinol. 36, 89-98, 2009 5) Ueberberg et al., Horm. Metab. Res. 41, 814-821, 2009 6) Shirasuna et al., Reproduction. 135, 519-525, 2008.
IMMUNOHISTOCHEMICAL STUDY OF GHRELIN, APELIN AND THEIR RECEPTORS IN THE DOG OVARIES
PIRINO, CAROLINA;MERCATI, FRANCESCA;POLISCA, Angela;CECCARELLI, Piero;DALL'AGLIO, Cecilia
2016
Abstract
Recent studies have shown that molecules, such as leptin, orexins and cannabinoids, are in general spread ubiquitously in the body very often involving anatomical structures not functionally related to appetite control [1, 2, 3]. The female genital tract is very often implicated, and this has led to the hypothesis that the same molecules are involved in its functional Control representing a point of contact between the animal's nutritional status and its functionality. In this context two proteic hormones, ghrelin and apelin, have been already highlighted in the ovary of some animal species [4, 5, 6] suggesting involvement in its functional control. The aim of the present work was to highlight the presence and the localization of ghrelin, apelin and their receptors in the ovary of non-pregnant bitches, with the purpose of providing data that may be useful in fully understanding the functionality of this organ. The experiment was conducted using six mixed-breed dogs, admitted to the day-hospital service at the Veterinary Teaching Hospital of the University of Perugia and regularly subjected to the ovario-hysterectomy by spaying. The ovaries were removed and immediately fixed in 4% formaldehyde solution and subsequently processed for embedding in paraffin. The immunohistochemical reactions were visualized on 5 μm serial sections, using anti-Apelin (ab59469), anti-APJ receptor (ab140508), anti-Ghrelin (ab129383) and anti-Ghrelin receptor (ab188986) polyclonal antibodies, avidin-biotincomplex and DAB as the chromogen. All the sections were counter-stained with haematoxylin. Sections in which the primary antibodies were omitted, were used as controls for unspecific staining. The immunohistochemical study showed a strong positivity for apelin, ghrelin and their receptors in some of the ovarian structures. In particular, a positive immuno-reaction for apelin and its receptor and for the ghrelin receptor seemed to be evident in the corpora lutea with a peculiar localization in some of the luteal cells. On the contrary, regarding ghrelin, a positive reaction for this molecule was evident within the wall of small arteries localized both inside the corpora lutea and in the connectival tissue. In general, the immuno-positive reaction seemed to affect only the cellular cytoplasm and was not observed in other ovarian structures or in the sections utilized as negative controls. Due to the presence of these molecules and their receptors in some of the luteal cells and within the wall of small arteries in corpora lutea and in connectival tissue, we can hypothesize that apelin and ghrelin might influence the functionality of ovarian structures where they are localized, suggesting the existence of autocrine/paracrine mechanisms of regulation. 1) Balogh et al., Reprod. Biol. Endocrinol. 8, 1-12, 2015 2) Liguori et al., Anat. Histol. Embryol. 43, 42-47, 2014 3) Hutch et al., Neuroscience. 300, 539-553, 2015 4) Du et al., Domest. Anim. Endocrinol. 36, 89-98, 2009 5) Ueberberg et al., Horm. Metab. Res. 41, 814-821, 2009 6) Shirasuna et al., Reproduction. 135, 519-525, 2008.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
