Morphometric and immunohistochemical study of the abomasum of red deer during prenatal development

Abstract

The red deer is well suited to scientific study, given its economic importance as an animal to be hunted, and because it has a rich genetic heritage. However, there has been little research into the prenatal development of the stomach of ruminants in general, and none for the red deer. For this reason, we undertook histological evaluation of the ontogenesis of the abomasum in red deer. Histomorphometric and immunohistochemical analyses were carried out on 50 embryos and fetuses from the initial stages of prenatal life until birth. The animals were divided for test purposes into five experimental groups: group I [1.4-3.6 cm crown-rump length (CRL); 30-60 days, 1-25% of gestation]; group II (4.5 -7.2 cm CRL; 67-90 days, 25 -35% of gestation); group III (8 -19 cm CRL; 97-135 days, 35 -50% of gestation); group IV (21-33 cm CRL; 142-191 days, 50-70% of gestation) group V (36-40 cm CRL; 205-235 days, 75 -100% of gestation). In the organogenesis of the primitive gastric tube of red deer, differentiation of the abomasum took place at 67 days, forming a three-layered structure: the epithelial layer (pseudostratified), pluripotential blastemic tissue and serosa. The abomasal wall displayed the primitive folds of the abomasum and by 97 days abomasal peak areas were observed on the fold surface. At 135 days the abomasal surface showed a single mucous cylindrical epithelium, and gastric pits were observed in the spaces between abomasal areas. At the bottom of these pits the first outlines of glands could be observed. The histodifferentiation of the lamina propriasubmucosa, tunica muscularis and serosa showed patterns similar to those described for the forestomach of red deer. The abomasum of red deer during prenatal life, especially from 67 days of gestation, was shown to be an active structure with full secretory capacity. Its histological development, its secretory capacity (as revealed by the presence of neutral mucopolysaccharides) and its neuroendocrine nature (as revealed by the presence of positive non-neuronal enolase cells and the neuropeptides vasoactive intestinal peptide and neuropeptide Y) were in line with the development of the rumen, reticulum and omasum. Gastrin-immunoreactive cells first appeared in the abomasum at 142 days, and the number of positive cells increased during development. As for the number of gastrin cells, plasma gastrin concentrations increased throughout prenatal life. However, its prenatal development was later than that of the abomasum in sheep, goat and cow.

Histomorphometric study of the goat stomach during prenatal development

“…; Masot et al . ): group I (CRL 1.5–4.3 cm), group II (CRL 4.4–8 cm), group III (CRL 9–17.5 cm), group IV (CRL 18–32 cm) and group V (CRL 33–47 cm). Goat embryos and fetuses were all obtained at a municipal slaughterhouse in Caceres (Spain), from routinely slaughtered pregnant females; Caesarean sections were performed in accordance with the provisions of Spanish Royal Decree 54/1995 on the protection of animals at slaughter.…”

Histomorphometric and Immunohistochemical Study of the Goat Rumen During Prenatal Development

“…The tunica mucosa of the abomasum, by contrast, has a simple, glandular, prismatic epithelium similar to that found in the stomach of monogastric species (Franco et al, 1993b;Masot et al, 2007a). Each compartment has its own distinct morphological features and resulting physiological peculiarities, but all four are jointly involved in the digestive process; the rumen is perhaps the most important compartment in physiological terms, in that it plays a key role in the breakdown and subsequent microbial digestion of cellulose, an essential nutrient for ruminants.…”

Ontogenesis of the rumen: A comparative analysis of the Merino sheep and Iberian red deer

“…The rumen of the sheep was subjected to numerous morphologic studies, including immunohistochemical and morphometric analysis (Franco et al 1992(Franco et al , 1993aRegodón et al 1996). The economic importance of the red deer due to hunting has led to this species being used in histogenetic studies of the gastric compartments in wild animals (Franco et al 2004a,b;Redondo et al 2005;Masot et al 2007).…”