Bovine Abomasum Research Articles

Cloning of the H,K-ATPase beta subunit. Tissue-specific expression, chromosomal assignment, and relationship to Na,K-ATPase beta subunits.

We have isolated cDNA clones encoding the bovine and rat gastric H,K-ATPase beta subunit. A bovine abomasum lambda gt11 cDNA library was screened with a monoclonal antibody raised against the rabbit H,K-ATPase beta subunit. A single positive phage clone containing an approximately 900-base pair cDNA insert was identified as reactive with the antibody. The identity of the cDNA was established by comparing the deduced amino acid sequence with sequences of cyanogen bromide fragments of the porcine H,K-ATPase beta subunit. Polymerase chain reaction and rapid amplification of cDNA ends were used to generate a cDNA fragment encoding the carboxyl-terminal portion of the rat gastric H,K-ATPase beta subunit. A rat stomach cDNA library was screened with the polymerase chain reaction product, and several full-length beta subunit cDNA clones were identified. The open reading frame predicts a protein of 294 amino acids with a molecular weight of 33,689. The rat H,K-ATPase beta subunit shows 41% amino acid sequence identity to the rat Na,K-ATPase beta 2 subunit and shares a number of structural similarities with Na,K-ATPase beta subunit isoforms. By analyzing the segregation of restriction fragment length polymorphisms among recombinant inbred strains of mice, we localized the H,K-ATPase beta subunit gene to murine chromosome 8. Northern and Western blot analysis reveals that this gene is expressed exclusively in stomach. Our results suggest that the H,K-ATPase and Na,K-ATPase beta subunits evolved from a common ancestral gene and may play similar functional roles in enzyme activity.

Epidemiology of abomasal nematodes of dairy cattle in Hokkaido, northern Japan.

The prevalence and intensity of infection with abomasal nematodiasis was studied in dairy cattle of Hokkaido, northern Japan, for successive two years. During the period of March in 1985 to September in 1987, a total number of 393 abomasa of Holstein-Friesian cows was examined for nematode parasites. Nematodes were detected from 75% of the cows. The prevalence of nematode species detected was Ostertagia ostertagi 250 (63.6%), Mecistocirrus digitatus 181 (46.1%), Trichostrongylus axei 85 (21.6%) and Haemonchus sp. 1 (0.3%). The prevalence and population composition of each growth stage varied seasonally in O. ostertagi and M. digitatus. The large percentage of arrested larvae, early L4 O. ostertagi and immature L5 M. digitatus, detected during the mid-winter and the increasing percentage of matured adult populations of both species in early spring revealed the occurrence of the autumn associated arrested development (hypobiosis) phenomenon in bovine abomasum nematodes of Japan.

Development of Gastrin- and Somatostatin-Containing Cells in the Pyloric Gland Region of the Bovine Abomasum

The ontogeny of gastrin- and somatostatin-containing cells in the pyloric gland region of the abomasum was studied in bovine fetuses, newborns and adults, using immunohistochemical techniques. A clear-cut developmental increase in the two kinds of endocrine cells could not be observed. The region of the lesser curvature displays more D and G cells than the greater curvature. Cells of both open and closed types are found from the earliest stages examined and continue to be present throughout the complete differentiation of the pyloric mucosa.

Influence of prostaglandins on bovine abomasum: biosynthesis and in vitro motility experiments

Pieces of the fundus, antrum pyloricum and pyloric sphincter of abomasa from freshly killed cows were studied for their capacity to biotransform arachidonic acid (AA) and for the effects of PG's on their in vitro motility. Biotransformation experiments revealed an AA-conversion (3.8 to 11.5 %) into cyclooxygenase and linoxygenase metabolites. The mucosa mainly synthetized hydroxy-eicosatetraenoic acids (HETE's) and PGE 2 + TXB 2. For the muscularis PGI 2 was the major AA-metabolite. Incubation in the presence of indomethacin resulted in a reduction of the AA-conversion into cyclooxygenase metabolites. In the fundic strips the three PG's induced an increase in tension. In the antral strips PGF 2α and PGE 2 resulted in an activation of spontaneous motility whereas PGI 2 provoked a dose-dependent inhibition. The three PG's induced an inhibitory response in the tissue strips from the pyloric sphincter. The results suggest a possible function for PG's in the control of tone and motility of the bovine abomasum.

Fine structure of developing gastric parietal cells in the bovine abomasum

Developmental changes in the fine structure of gastric parietal cells were studied in bovine fetuses and neonates. Definitive parietal cells first appeared as non-granular light cells at five months of fetal age (in a 48 cm long fetus). At this age they had a microvillous apical surface and cytoplasmic vesicles which accumulated at the apex. Intracellular canaliculi appeared with an increase in mitochondria at six to seven months of fetal age. Fully differentiated parietal cells were present from the eighth month of gestation. At birth they were similar in appearance to those of the adult abomasum.

Effects of breed, diet and sex on the alkaline phosphatase activity in walls of the bovine rumen and abomasum.

Alkaline phosphatase (APase) activity in tissue samples, with adherent bacteria, was measured from two sites in the rumen and from two sites in the abomasum of 57 yearling Angus and Hereford bulls and heifers fed a high or a low energy diet. In the rumen, APase activity was higher at the caudoventral blind sac than at the dorsal sac in animals of both breeds fed the high energy diet and in Angus bulls fed the low energy diet, but the reverse was observed in Hereford bulls fed the low-energy diet (P less than .01). In the abomasum, APase levels were higher for bulls than heifers (P less than .01) and higher at the fundic than at the pyloric region (P less than .01). Morphological studies also showed that rumen samples from animals fed a high energy diet exhibited a more widely distributed APase activity and an increase in the digestive recycling of epithelial cells that produced some "pitting" of the tissue. The higher APase activity of the epithelial tissue of animals fed the high energy diet may be explained by the greater rate of cell death and renewal indicated by the higher mitotic index reported by other researchers who have studied the cell cycle of the rumen epithelium in ruminants fed high and low energy diets.

Developmental changes in the inner surface structure of the bovine abomasum.

ウシの胎齢1.5ヵ月の胎仔より新生仔に至るまでの第四胃胃底部の粘膜表面すなわち内面構造についてその形態学的分化行程を観察し, とくに胃小窩と胃腺の形成について走査型電子顕微鏡と復構模型を用いて精査した. 初期胎仔の第四胃表面上にはすでに多くの細かなシワをもつ, ラセンヒダが現われていた(1・5-2ヵ月). その後ヒダの表面のシワは伸長して多くの直線状の縦走する隆起となり(3-4ヵ月), 続いておのおのの直線状の隆起上のところどころに浅いくびれが現われ, その数も次第に増加して, 個々の独立した隆起を形成する. この隆起下の粘膜固有層はすでに蜂巣状の網目を示し, 間に深いくぼみを形成していた(4-5ヵ月). その後, おのおのの隆起は次第に変形して俵状になり(5-7ヵ月), さらに月齢が進むと隆起も狭くなり, その間の溝が拡大してくる(7-9ヵ月). 新生期に至るとおのおのの隆起も次第に平坦になり, 溝の一部は胃小窩として拡大する. この胃小窩の出来方には変異があり, 1例では4個の隆起が接着して, その間の溝の接点が深くくぼみ胃小窩となり, 残りの部分の溝は消失する. またこれらの隆起に背中合わせに存在する隆起間にも胃小窩ができる場合があり, このようにして隆起と隆起との間の溝は失なわれ, 胃小窩が拡大し明瞭になるように思われた.

Diagnosis of the surgical disorders of the bovine abomasum

Diseases of the abomasum comprise a most interesting group of conditions only really appreciated in comparatively recent years.

Physiological aspects of the omasum and abomasum

The abomasum can be envisioned as a structure having a somewhat primitive contractile pattern and the capability of secreting large volumes of acid fluid. In addition, it may have the capacity of absorbing a portion of the chemical products resulting from rumen fermentation. Both the secretory activity and the motility patterns of the abomasum can be apparently altered by the nature of the ingesta presented to it. Are thesephysiological aspects relevant when clinical disorders of the bovine abomasum are considered? Perhaps they are very relevant. A subsequent paper will attempt to relate research information to certain clinical disorders of the abomasum and to speculate on possible pathophysiologic processes involved.

Isolement, purification et propriétés de deux zymogènes gastriques bovins. Propriétés des protéases correspondantes

Summary This communication describes the isolation and purification of two zymogens from bovine abomasum, showing characteristic properties of pepsinogens. u —Stability above pH 7. —No proper proteolytic activity at pH 5.25. —Activation at low pH, probably corresponding to the separation of a basic part of the molecule. —Stability of the corresponding enzymes below pH 6. Elution diagrams, starch and agar gel electrophoresis and N-terminal residue analysis are given as criteria of purity. The proteolytic activity against hemoglobin as a function of pH and the inactivation at alcaline pH of the two corresponding pepsins are compared with those of rennin and swine pepsin.

Differences Between Calf and Adult Bovine Rennet

Activated enzyme extracts of adult bovine abomasum (adult bovine rennet) tissues contained 5 to 15% milk clotting activity attributable to pepsin. Starch gel electrophoresis in urea and mercaptoethanol revealed different patterns than for calf rennet extract. Differences also were in casein-agar gel diffusion patterns at pH 6.8. Lipolytic activities were similar. Proteolytic activity on casein substrate at pH 9.0 was evident in adult bovine but not in calf rennet or in swine pepsin. However, milk clotting activities in adult bovine and calf rennets were destroyed at comparable rates at pH 9.0. Proteolytic activity of adult bovine rennet was significantly reduced by milk clotting activation at pH 2.0. Casein-agar gel diffusion at pH 9.0 was useful in detecting blends of adult bovine and calf rennet. Adult bovine rennet could be detected at 1% concentration. Accelerated ripening and proteolytic activity studies of adult bovine and calf rennet at pH 5.2 indicated possible differences in their effects upon the aging properties of cheese.

Perforation of the abomasum and duodenum and abomasal displacement in cattle.

Abstract Extract Despite early reports by Scandinavian workers referred to by Blood (pers. comm.) and Steere (1961 Steere, J. H. 1961. Modern vet. Practice, 42: 45–45. [Google Scholar]), it was not until 1950 that surgical correction of clinical conditions of the bovine abomasum was reported in English (Begg, 1950 Begg, H. 1950. Vet. Rec., 62: 797–797. [Crossref], [PubMed] , [Google Scholar]; Ford, 1950 Ford, J. N. 1950. Vet. Rec., 62: 763–763. [Crossref], [PubMed] , [Google Scholar]). Following this there have been a number of clinical reports and several reviews (Steere, 1959 Steere, J. H. 1959. Modern vet. Practice, 40: 36–36. [Google Scholar]; Neal and Pinsent, 1960 Neal, P. A. and Pinsent, P. J. N. 1960. Vet. Rec., 72: 175–175. [Google Scholar]; Pinsent, et al., 1961 Pinsent, P. J. N., Neal, P. A. and Ritchie, H. E. 1961. Vet. Rec., 73: 729–729. [Google Scholar]).

A Post-Mortem Survey of Some Features of the Bovine Abomasum

A Post-Mortem Survey of Some Features of the Bovine Abomasum

Preparation, Assay, and Preliminary Characterization of Bovine Gastrin

Summary A gastrin-like gastric secretory stimulant was isolated by an alkaline extraction method from pyloric and fundic mucosae of the bovine abomasum. Secretory activity was measured after subcutaneous injection into Gregory and Heidenhain pouch dogs. The injected material was shown not to be histamine. The reaction to bovine gastrin is usually delayed for 60 to 90 min., in contrast with porcine gastrin, which reacts within 30 min., and with histamine, which reacts in even less time. The most active fractions of bovine gastrin were obtained by isoelectric precipitation at pH 3.0–4.0, in contrast with porcine gastrin, which has highest activity in the fraction precipitated at pH 5.0–5.5. The response to bovine gastrin, as is the case with the porcine material, persists for from 2 to 4 hr., contrasting with the speedy decline after response to histamine. In preliminary purification, we found a nondialyzable fraction, perhaps conjugated with or tenaciously held by a larger molecule, and a dialyzable fraction. Partial purification by ion-exchange has been effected. Preliminary chemical analysis shows that crude bovine gastrin is very similar to crude porcine gastrin in IR and UV spectra and phosphorus content.