Gallbladder motility in sheep: effects of cholecystokinin and related peptides

Gallbladder motility was recorded as tonic and small amplitude (rhythmic) contractions in conscious sheep fitted with miniaturized strain-gauge force transducers located in the corpus and fundus. Nichrome wire electrodes were chronically implanted in the gastroduodenal area. Both tonic and superimposed rhythmic gallbladder contractions were increased during feeding. They decreased during the periodic phases of antroduodenal quiescence. The excitatory effects on gallbladder and antroduodenal motility were mimicked by pilocarpine and blocked by atropine. Cholecystokinin (CCK-OP) and caerulein elicited motor responses of the gallbladder in a dose-related manner without antroduodenal stimulation. In contrast, pentagastrin induced gallbladder motor responses with concomitant stimulation of the antroduodenal area. The results suggest that feeding may act to trigger gallbladder motor activity through a mechanism related to the increased antroduodenal activity. Direct effects of CCK-OP and caerulein confirm that gallbladder motor function is also mediated through specific receptor sites.     

A new hemolytic assay for bovine serum complement and its application during experimental bovine anaplasmosis

A new hemolytic assay for bovine complement is presented. Using this assay we found a significant reduction in bovine serum complement activity during the acute phase of anaplasmosis, and an increase in the sensitivity of the red blood cells (RBC) to bovine complement lysis in vitro. The new hemolytic test is performed with bovine RBC, rabbit anti-bovine RBC serum and bovine serum complement. An isotonic sucrose Tris-buffered saline solution of ionic strength 0.094 and pH 7.2 was found to be adequate for this test. The titres obtained with this new assay, which uses autologous RBC, are comparable with those obtained using the guinea pig RBC assay. The finding of a reduction in bovine serum complement during anaplasmosis may be suggestive of a mechanism responsible for the pathology of this disease.     

Corynebacterium pseudotuberculosis exotoxin: fatal hemolytic anemia induced in gnotobiotic neonatal small ruminants by parenteral administration of preparations containing exotoxin

Inoculation of live Corynebacterium pseudotuberculosis, culture supernatant, ammonium sulfate-fractionated crude exotoxin, or chromatographically purified exotoxin preparations into gnotobiotic small ruminants (n = 13) caused death of the ruminants within 48 hours. Characteristic changes observed in animals living greater than or equal to 2 hours after inoculation included hemorrhage and edema at the site of injection, severe hemolytic anemia and hemoglobinuria, dark red fluid in body cavities, lung edema, and icterus. The crude exotoxin preparation caused a syndrome of acute shock in 2 lambs that died within 15 minutes after inoculation. Clinical and pathologic responses of animals inoculated with culture supernatant and purified toxin were similar. Histopathologic evidence indicated that the exotoxin caused necrotic changes in the proximal convoluted tubules of the kidneys. Inoculation with live organisms caused multiple foci of suppurative inflammation in skeletal muscle and adjacent adipose tissue, whereas such changes were not observed in animals administered exotoxin preparations. Although C pseudotuberculosis exotoxin induced a hemolytic anemia in the experimental animals, it did not lead to in vitro lysis of ovine, caprine, or bovine erythrocytes, unless they had been sensitized with Rhodococcus (Corynebacterium) equi filtrate. The toxic sphingomyelin-specific phospholipase D from C pseudotuberculosis had a molecular weight of 31,000 daltons and an isoelectric point of approximately 9.6. The elution profile of exotoxin on a carboxymethyl Sephadex column was studied and the majority of the enzymatic activity was eluted by a NaCl gradient (0.25M to 0.7M) with a maximum at 0.35M NaCl.(ABSTRACT TRUNCATED AT 250 WORDS)     

Purification and partial characterization of growth hormone from the dromedary (Camelus dromedarius)

Camel growth hormone (camGH) was isolated from the insoluble residue left after extraction of the gonadotropins FSH and LH from a single batch of one-humped camel (Camelus dromedarius) pituitaries. Only one form of camGH was isolated and characterized; no glycosylated form of camGH could be evidenced. The isoelectric points (pI) of camGH was determined by chromatofocusing.

The N-terminal amino-acid sequences of camGH was determined and compared to those of GHs from other species. The availability of this hormone and our better knowledge of its structure will permit to undertake the study of its structure-function relationships and of its physiological functions in this economically important species.     

Nitrogen-fixing ability of traditional and new pulse crops in western Siberia

An increase in the nitrogen-fixing ability of annual pulses by 1.5–2 times under the effect of inoculating seeds with Rhizotrophin is established in 3-year field experiments. The quantitative parameters of biologically fixed nitrogen and additional grain yield of pulse crops and spring wheat planted after them are determined. Original Russian Text ? G.P. Gamzikov, P.R. Shott, A.P. Kozhemyakov, 2008, published in Doklady Rossiiskoi Akademii Sel’skokhozyaistvennykh Nauk, 2008, No. 2, pp. 23–25.