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SUMMARY

Technetium-99m sulfur colloid scintigraphy was used to study alterations of reticuloendothelial function in 7 dogs with experimentally induced biliary cirrhosis and portosystemic shunting. Scintigraphic studies were performed before and 6 weeks after common bile duct ligation. Radiocolloid plasma clearance rate was determined by measuring activity in plasma samples and by analyzing the rate of liver uptake on dynamic scintigraphic image sequences. Percentage of uptake in the liver, spleen, and lungs, as well as the ratio of hepatic-to-extrahepatic uptake, was determined from static equilibrium images. Relative to preoperative values, there were significant decreases in plasma clearance rate, percentage of fiver uptake, and ratio of hepatic-to-extrahepatic uptake and significant increases in percentage of spleen and lung uptake on postoperative studies.

The mechanism of technetium-99m-labeled sulfur colloid extraction by the liver is different from that of other radiocolloids; it does not require active phagocytosis or pinocytosis. Thus, fiver uptake of this tracer principally reflects effective liver blood flow. Portosystemic shunting was documented in these dogs at the time of the postoperative radiocolloid scans, and we believed was responsible for the decrease in liver reticuloendothelial activity. Possible mechanisms for the increased splenic and pulmonary reticuloendothelial activities are discussed.

Free access
in American Journal of Veterinary Research

Abstract

Objective

To elucidate the spatial and temporal expression of a porcine lactoferrin (LTF) gene.

Animals

4 female and 4 male Large White pigs.

Procedures

We examined LTF expression in various organs excised from the pigs, using northern blot hybridization with a porcine LTF cDNA probe. Antibodies against porcine LTF were raised in rabbits and were used along with immunohistochemical staining to localize the LTF protein.

Results

High amounts of porcine LTF mRNA were detected in the secreting mammary gland and epididymis. This distribution is consistent with that of porcine LTF examined by immunohistochemistry. In female pigs, porcine LTF mRNA concentration increased remarkably in the ductal cells of the lactating mammary gland then significantly decreased at day 21 after parturition. Furthermore, specific staining for LTF was observed in the epithelial cells of the gastrointestinal tract of female pigs, but not in the uterus, ovaries, spleen, kidneys, pancreas, muscles, heart, brain, lungs, or liver of postpartum female pigs, or in the testes of male pigs.

Conclusions

Gene expression of porcine LTF is closely related to lactation in the mammary gland. Distribution of LTF in the epididymis suggests that LTF may have a regulatory role in development of the reproductive tract of male pigs. (Am J Vet Res 1997;58:1152–1158)

Free access
in American Journal of Veterinary Research

SUMMARY

Arterial blood samples were obtained at rest, just before, and 5 minutes after a 704-m race, to quantify changes in hematologic variables, plasma electrolyte and protein concentrations, osmolality, and acid/base variables. Changes in plasma volume were estimated from the change in plasma protein concentration. Immediately prior to the race, plasma volume decreased by 10% from rest and total circulating rbc volume increased by 60%, attributable to increased rbc number rather than size. Increases in blood volume (VB) by 24% and pcv by 29% also were detected before the race. Five minutes after the race, plasma volume was 21% below the resting value and total circulating rbc volume had increased 73% above the resting value, resulting in a 40% increase in pcv. Contraction of the spleen appeared responsible for increased pcv and VB before the race and maintenance of VB after the race.

Plasma chloride concentration was the same before and after the race; the chloride content of the plasma decreased by the same fraction (22%) as did the plasma volume, indicating Cl- loss from the plasma. Plasma Na+ content decreased by a smaller fraction (13%), causing Na+ concentration to increase from 151 mEq/L at rest to 167 mEq/L after the race. Assuming that Na+ concentration was the same throughout the extracellular fluid, H2O likely moved into the intracellular compartment. As a consequence of these changes, the inorganic strong ion difference in plasma increased by about 16 mEq/L, tending to minimize the acid/base disturbance induced by the 33 mEq/L increase in lactate concentration.

Results indicated that the physiologic changes taking effect during strenuous sprint exercise in Greyhounds enhance blood volume and aid in acid/base homeostasis, both of which are adaptive for this type of exercise.

Free access
in American Journal of Veterinary Research

SUMMARY

Over a 54-hour period, blood was removed from 8 adult sheep (body weight, 38.1 ± 0.5 kg, mean ± sem ) in 9 episodes, 5 on day 1, 3 on day 2, and 1 on day 3. Cumulative blood loss was 1,630 ± 63, 2,380 ± 71, and 2,693 ± 69 ml on days 1, 2, and 3, respectively. Blood samples (20 ml) were collected from 5 control ewes (33.8 ± 2.8 kg) at equivalent times. Over the first day, mean arterial blood pressure decreased in the hemorrhaged sheep from 101 ± 2 mm of Hg to 76 ± 5 mm of Hg, but returned to control values by the beginning of the second day and, thereafter, was not different from control values. Heart rate was increased after the first hemorrhage episode and remained high throughout the entire protocol. Over the entire period, there were statistically significant decreases in hematocrit, plasma osmolality, sodium, total calcium (P < 0.001 ), potassium, and chloride values (P < 0.05 ). There was no change in plasma phosphate, bicarbonate, creatinine, or magnesium concentrations and an increase in plasma urea nitrogen (P < 0.001 ) concentrations. Plasma arginine vasopressin concentration was increased significantly (P < 0.001 ) over the entire period. Plasma acth concentration was significantly (P < 0.05 ) increased over time, but only some values on day 1 were significantly outside the normal range of the control group data. Because of wide variation between sheep, the group data for aldosterone were not significantly different from control values. Blood volume was restored on day 1 with fluid of osmolality, Na, and Cl composition equivalent to that of plasma. The effects of arginine vasopressin were apparent by day 2, when the major decrease in osmolality and Na and Cl concentrations were observed. The sheep has good capacity to withstand severe, prolonged hemorrhage, most likely because of a large reserve of rbc in the spleen; hematocrit remained at 31% of control values when an estimated 100 % of initial circulating blood volume had been removed.

Free access
in American Journal of Veterinary Research

the diffuse changes seen with glucocorticoid-induced vacuolar hepatopathy is usually more difficult than visualization of focal lesions. Comparing echogenicity of the liver with that of the kidney or spleen and visualization of the portal vessels can

Full access
in American Journal of Veterinary Research

concurrently from the spleen at 3 hours and 3 days. Red blood cells from both sites were isolated, labeled with fluorescent streptavidin-PE (1.2 μg of streptavidin-PE/1 × 10 6 RBCs), and analyzed by use of flow cytometry to determine the percentage of RBC

Full access
in American Journal of Veterinary Research

and other animals indicate that transfusion with erythrocyte concentrate stored for long periods (eg, 21 to 42 days) is followed by an accelerated clearance of cells. 35–39 Damaged transfused cells are removed by macrophages in the spleen and liver of

Full access
in American Journal of Veterinary Research