Quantitative and qualitative changes in blood leukocytes in the porcine ovary.

The distribution of blood leukocytes in the preovulatory follicle (PO) and in the corpus luteum (CL) of the pig was studied by light microscopy. The number of macrophages increased in the freshly luteinized follicle, decreased subsequently in the developing and mature CL, and then increased again in the regressing CL. However, the relative proportion of macrophages as a percent of total blood leukocytes present did not change throughout the cycle. The increase in the number of lymphocytes was the greatest increase after ovulation as compared to all the other blood leukocytes observed. Even though the number of lymphocytes decreased thereafter, their numbers expressed as a percent of total blood leukocyte number remained high in the developing and mature CL. Eosinophils were the most prominent blood cell type present in thecal tissue of PO and in the regressing CL. In other stages of the CL, few eosinophils were observed. Neutrophil numbers remained moderate and unchanged throughout most of the estrous cycle except in the regressing CL, where the number of neutrophils was slightly increased. Low numbers of plasma cells were observed in all structures studied and no significant changes due to stage were apparent. The distribution of lymphocytes in the corpus hemorrhagicum (CH) and eosinophils in the regressing CL was different in different regions of the ovarian structure. In summary, blood leukocytes, most notably macrophages, lymphocytes and eosinophils, differentially migrate into specific structures of the ovary at specific stages of the estrous cycle of the pig. The possible involvement of these blood leukocytes in the modulation of ovarian events is discussed.

Atresia of the right atrioventricular orifice with complete transposition of the great arteries in a horse.

The heart of a 6-week old Arabian filly with a history of poor health and exercise intolerance revealed at postmortem examination, multiple cardiac malformations which included atresia of the right atrioventricular orifice (tricuspid atresia, with associated atrial and ventricular septal defects), complete transposition of the great arteries, anomalous drainage of the venae cavae and coronary sinus into the left atrium, coarctation of the aorta, and a small but patent ductus arteriosus. The course of blood through the heart was suggested and discussed.

Common ventricle with separate pulmonary outflow chamber in a horse.

On the basis of clinical and laboratory examinations, a ventricular septal defect or a variant of the tetralogy of Fallot was suspected in a 3-year-old filly with a history of poor growth rate and exercise intolerance. The filly was euthanatized and found to have a 3-chambered heart (cor triloculare biatriatum). The heart had 2 normally formed atria and a large common ventricle into which the right and left atrioventricular orifices opened and from which the aorta arose. There was a small separate chamber from which the pulmonary trunk originated. This chamber communicated with the common ventricle through a large oval opening along the dorsal border of the displaced, interventricular septum.

Effect of vitamin A deficiency on mammary gland development and susceptibility to mastitis through intramammary infusion with Staphylococcus aureus in mice.

Weanling mice were fed 0 or 150 micrograms retinol equivalent/kg of diet for 5 weeks, were bred, and allowed to complete gestation. On day 3 of lactation, all mice were separated from their litters for 1 hour and were then anesthetized. The 4th right or left mammary gland was inoculated with 0.1 ml of S Aureus (10(10) colony-forming units/0.1 ml). Exactly 24 hours after inoculation, the mice were euthanatized and the mammary glands were removed and fixed for histologic evaluations. Vitamin A-deficient dams had smaller litter size and lower liver stores of vitamin A; however, deficiency was not severe enough to produce external signs of vitamin A deficiency in the dams. Morphologic studies showed large areas of adipose tissue, greatly reduced ductal and lobule-alveolar development, and decreased total secretory activity in mammary glands from vitamin A-deficient females. On the other hand, mammary glands from vitamin A-supplemented mice had extensive lobule-alveolar development and highly distended alveoli. Extensive necrosis of alveolar tissue was observed in staphylococcus-infused mammary glands of all mice. Large numbers of leukocytes and cell debris were present in the lumen of alveoli and ducts. However, mammary glands from vitamin A-deficient females had more extensive pathologic damage compared with corresponding glands from vitamin A-supplemented mice. Results indicted that vitamin A-deficient mice had reduced mammary development and increased pathologic damage to the mammary gland after intramammary challenge with staphylococcus.

Effect of histamine on blood flow to the adrenal glands of pigs.

Blood flow to the adrenal glands was measured with radioactive microspheres labeled with 85Sr in 25-37 kg pigs following the intravenous infusion of physiological saline solution or histamine solution (2 micrograms/kg/min) for 60 minutes. Total blood flow averaged 2.28 ml/min/gland for control pigs and 4.38 ml/min/gland for histamine-treated pigs (P less than .0005). Mean blood flow to the adrenal glands of histamine-treated pigs (3.15 ml/min/g) was 82% higher than that of control pigs (1.73 ml/min/g); the difference was highly significant (P less than .0005). The result of this study showed that histamine caused an increased blood flow to the porcine adrenal glands.

Regional renal blood flow in ewes.

Regional blood flow to the kidneys was measured in 6 ewes by injecting carbonized microspheres (15 micrometer +/- 5) labeled with 85Sr into the left ventricle. There was no significant (P greater than 0.25) difference in the mean arterial pressure before and after injection of the microspheres. Normal values of blood flow to the outer cortex, inner cortex, and medulla were determined. The blood flow to the outer cortex was highest, followed (in a decreasing order) by the inner cortex and the medulla. Significant differences in blood flow were not detected between dogs, and sheep. The microsphere technique, based on Fick's principle, requires minimum instrumentation and does not require surgical manipulation of the kidney. The objective of the present experiment was to determine and compare the blood flow to regions of the ovine kidneys.

Regional blood flow to the stomach and small intestine in swine.

The radioactive microsphere technique was used to measure regional blood flow to the stomach and small intestine of pigs weighing 20 to 37 kg. Mean regional blood flow (ml/min/100 g of tissue) was least in the nonglandular region, followed in an increasing order by the pyloric gland, cardiac gland, and proper gastric (fundic) gland regions. The region of the proper gastric glands accounted for 47.5% of the total gastric blood flow, with 24.9%, 23.8%, and 3.7% of the total flow going to the cardiac gland, pyloric gland, and nonglandular regions, respectively. Although there appeared to be a blood flow gradient in the small intestine, no significant difference in blood flow between the duodenum, jejunum, and ileum was observed. Mean blood flow to the small intestine was significantly greater than that to the stomach.

Effect of histamine and prostaglandin E2 on gastric blood flow in swine.

Gastric blood flow was measured by the radioactive microspheres entrapment technique following the IV infusions of saline solution, histamine, or prostaglandin E2 and histamine to young pigs. Pigs treated with histamine (2 micrograms/kg/minute for 60 minutes) had significantly higher blood flow to the gastric mucosa (P less than 0.025), particularly to the region of the proper gastric (fundic) glands (P less than 0.01), than did the saline-treated pigs. When prostaglandin E2 (1 microgram/kg/minute for 60 minutes) was infused simultaneously with histamine, there was a slight, but not significant, decrease (P less than 0.10) in mucosal blood flow to the region of the proper gastric glands. Analysis of the percentage distribution of blood flow indicated that the increase in blood flow to the region of the proper gastric glands after histamine infusion may be due to a redistribution of blood flow from the cardiac gland region.

Effect of prednisone on gastric blood flow in swine.

The effect of long-term prednisone treatment on gastric blood flow, as it relates to the development of gastric lesions, was studied. Young pigs were given (IM) saline solution or prednisone (10 mg/kg) each day for various periods. Blood flow was measured, using the radioactive microsphere entrapment technique, at the end of 7, 14, and 21 days of treatment. Pigs treated with prednisone had hemorrhages in the proper gastric (fundic) gland area of the stomach. Blood flow to the mucosa and total wall of the nonglandular, cardiac gland, fundic gland, and pyloric gland regions of the stomach was higher in prednisone-treated pigs. Gastric lesions were not observed in the saline-treated pigs. Regional blood flow to the gastric mucosa increased during the formation of prednisone-induced gastric lesions in swine.

Plasma concentrations of pepsinogen and corticosteroid in relation to gastric lesions in swine.

Plasma pepsinogen and plasma corticosteroid concentrations were found to be unrelated to the presence or severity of gastric lesions in swine. Mean plasma pepsinogen and corticosteroid concentrations were significantly different between collection periods, with significantly higher values occurring during cold weather. Seemingly, plasma pepsinogen and corticosteroid values are neither indicative of susceptibility to, nor of the presence of, gastric erosions or ulcers in swine. However, plasma pepsinogen concentration may be a potential indicator of stress.

Effects of prednisone on gastric secretion and development of stomach lesions in swine.

In pigs treated with various doses of prednisone, pathologic changes appeared in the glandular region of the stomach, mainly in the fundic area and rarely and less severely in the cardiac and pyloric mucosae. The characteristic lesion was hemorrhagic gastritis; this was associated with massive gastric hemorrhages in pigs given the larger doses of prednisone. Epithelial changes were found in the esophageal area, but there were no ulcers. In pigs with gastric fistulas, prednisone administered at dose levels of 10 mg/kg of body weight for 8 days produced a significant increase in the volume and the acidity of gastric secretion. Hexosamine output, but not concentration, increased significantly during the treatment period. Change in pepsin secretion was sit significant. Prednisone did not produce an immediate change in gastric secretion--there being a latent period lasting 1 to 2 days before marked changes were observed. After peak changes occurred (3rd or 4th day of treatment), acidity gradually decreased to pretreatment level toward the end of the treatment period. This indicates that although increased acidity may be involved in the development of lesions in the glandular region, other factors probably have a role also in the pathogenesis of steroid-induced stomach lesions in swine.