Serum 25-hydroxyvitamin D concentration in Japanese Akita dogs: A survey.

Low serum level of vitamin D has been linked to numerous diseases. The Akita breed of dog shows a high incidence of immune-mediated diseases such as uveodermatologic (UVD) syndrome and sebaceous adenitis (SA). Furthermore, in Japanese Akita dogs, skin depigmentation often appears after birth at different ages, in healthy dogs, and without any other symptoms. In humans poliosis is associated to low vitamin D level. The aim of this survey was to evaluate serum 25-hydroxyvitamin D (25(OH)D) levels in Japanese Akita dogs. One hundred and three Akita blood samples were collected for the 25(OH)D evaluation. Age, sex, current disease, presence and location of skin depigmentation, and diet were reported on a medical record. Based on history and clinical examination, dogs were classified according their health status as healthy (HE) or pathological (PA). The overall mean of 25(OH)D concentration was 82.42 ± 26.14 ng/mL, whereas the concentrations in the healthy dogs were significantly higher (84.90 ± 3.36 ng/mL) in comparison with the dogs with diseases (72.13 ± 4.09 ng/mL) (P < 0.01). In this study, the depigmented healthy dogs showed low level of 25(OH)D and very similar to the sick group. The appearance of depigmented areas associated with low levels of vitamin D could be considered as an alert sign in Akitas as well as in humans. However, clinical trials should also be carried out to establish whether vitamin D supplementation could be an effective preventive treatment to limit the onset of immune-mediated diseases in Japanese Akita dogs.

Acid phosphatase and cathepsin D are active expressed enzymes in the placenta of the cat.

Enzymes are crucial for the metabolism of macromolecular substrates. In the great majority of cells, most enzymes are constitutive. Nevertheless, inducible enzymes can predominate, determining specialized cell functions. Within this context, histochemistry/immunohistochemistry and biochemistry were used to investigate expression of peroxidase and reduced nicotinamide-adenine dinucleotide phosphate (NADPH)-oxidase, as well as the expression and activity of cathepsin D and acid phosphatase, in trophoblast cells within the endotheliochorial labyrinth and marginal hematoma of the term cat placenta. In the marginal hematoma, elevated Cathepsin D expression and activity was accompanied by erythrophagocytosis. In contrast, acid phosphatase activity was much more intense in the labyrinth, where metabolic exchanges occur. Peroxidase and NAD(P)H-oxidase were predominantly active in trophoblast cells within endosomal vesicles of different placental compartments, indicating that, although reactive oxygen species might participate in endosomal/lysosomal processes, they are not territorially specific or functional markers. These findings highlight differential characteristics of cathepsin D and acid phosphatase activity within each placental compartment, thereby contributing to the comprehension of the territorial role played by the placenta and facilitating future metabolic studies.

Developmental changes at the materno-embryonic interface in early pregnancy of the alpaca, Lamos pacos.

This study analyses the manner in which trophoblast cells adhere to uterine epithelium and the subsequent interactions that contribute to the establishment of epitheliochorial placentation in the alpaca Lama pacos. Specimens at the luteal and follicular phases and at 22, 26, 30 and 45 days of pregnancy (op) were processed for morphological studies. On day 15 op, the blastocysts are completely free within the uterine lumen, with implantation starting around day 20. On days 22 and 26 of gestation, the trophoblast is apposed to the epithelial surface of the uterus, with areas of contact and adhesion by means of complex interdigitation. Implantation sites occur prevalently in the left uterine horn, but an expanded trophoblast also occupies large extensions of the right horn, where the maternofetal interaction shows peculiar areas of apposition. As development continues, attachment areas become more extensive. On days 30 and 45, many secretory granules can be seen in the uterine epithelium, while giant multinucleate cells appear interposed between the remaining trophoblast cells, showing intense alkaline phosphatase activity, deposits containing iron and PAS-positive granules. Placental lactogen hormone is not present within the cytoplasm of the binucleate or multinucleate trophoblast cells. By day 30 of gestation, the trophoblast layer is lined by an extraembryonic connective tissue that by day 45 is well vascularized, thus indicating the starting point of placental formation. Fetal and maternal capillaries indent the epithelium and the trophoblast, narrowing the specialized areas of exchange, which occur along the entire maternofetal interface, characterizing the diffuse nature of this placenta.

NADPH-diaphorase activity and nitric oxide synthase isoforms in the trophoblast of Calomys callosus.

The pattern of expression of a variety of placental nitric oxide synthase isoforms has contributed to elucidating the regulatory mechanisms of nitric oxide (NO) synthesis during gestation. The maintenance of vascular tone, attenuation of vasoconstriction, prevention of platelet and leukocyte adhesion to the trophoblast surface, and possible participation in uterine blood flow seem to be the main functions of NO generated at the fetal-maternal interface in humans and mice. Extending this knowledge to other rodent species commonly used as laboratory animals, in this study we focus on NADPH-diaphorase activity and the distribution of nitric oxide synthase isoforms (NOS) in the trophoblast cells of Calomys callosus during different phases of pregnancy. NADPH-diaphorase activity was evaluated cytochemically and the presence of NOS isoforms detected by immunohistochemistry. These techniques were performed on pre- and postimplantation embryos in situ and in vitro, as well as in placentae on d 14 and 18 of pregnancy. Neither NADPH-diaphorase activity nor inducible or endothelial NOS isoforms were found in pre-implanting embryos except after culturing for at least 48 h, when some of the embryonic cells were positive for the diaphorase reaction. On d 6.5 of pregnancy, trophoblast cells showed intense diaphorase activity both in situ and under in vitro conditions. A positive reaction was also found in the different placental trophoblast cells on d 14 and 18 of pregnancy. The inducible NOS (iNOS) isoform, but not the endothelial isoform, was immunodetected in trophoblast cells from the placenta and from postimplantation embryos in situ and under in vitro conditions. These results strongly suggest the production of NO by the iNOS isoform in the trophoblast of Calomys callosus after embryo implantation. The data also emphasise a possible role for the trophoblast in producing and releasing cytotoxic molecules at the fetal-maternal interface.