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Biomedical subjects

J A Barrowman

Publications and source records attributed to J A Barrowman.

At least 55 records · Page 3Linked to original sources
PubMed1982

Trophic effects of cholecystokinin octapeptide on the pancreas of the Syrian hamster.

Repeated subcutaneous injections of cholecystokinin octapeptide (CCK-OP) to Syrian golden hamsters for 10 days elicited a marked trophic effect on the pancreas, characterized by increased pancreatic weight and increased RNA/DNA ratios with an enhanced content of amylase in the pancreas in treated hamsters. These responses were observed after relatively small doses (100--300 ng CCK-OP x day-1 . 100 g body weight-1) of the hormone over a 10-day period. Although there was a small increase in total pancreatic DNA there was no definite evidence of hyperplasia in response to CCK-OP. DNA synthesis, as measured by histoautoradiography of tritiated thymidine labelled tissues, was increased in pancreatic acinar and islet cells, but not in ductal cells. This investigation, therefore, demonstrates a trophic action of CCK on the pancreas of the hamster similar to that reported for the rat and this may have relevance in studies of carcinogenesis since the hamster is an established species for studying pancreatic cancer.

Amylases↗
PubMed1982

Exclusion phenomenon in the liver interstitium.

Measurements were made of hepatic interstitial fluid volume and the proportion of that space occupied by 125I-labeled lactoglobulin, albumin, and gamma-globulin in anesthetized cats. 51Cr-red blood cells and 99mTc-diethylenetriaminepentaacetic acid were used to estimate tissue blood volume and extracellular volume, respectively. Hepatic lymph was assumed to represent the interstitial fluid of the liver. The degree of exclusion of each protein increased with increasing molecular size. At normal hepatic venous pressures, the excluded volume fraction for cat albumin was 0.41. Elevation of hepatic venous pressure by 12.5 mmHg caused a fourfold increase in hepatic lymph flow with an increase in interstitial volume and a reduction in albumin exclusion. When the exclusion of heterologous (human) albumin was studied in the cat liver, much higher values were obtained than with homologous albumin. This effect may be due to polymerization of commercial human albumin on storage.

Animals↗
PubMed1982

Effects of various secretagogues and human carcinoid serum on lymph flow in the cat ileum.

Previous studies from our laboratory indicate that the lymph flow response of the cat ileum to net volume secretion is dependent upon the mechanism involved in the secretory process, i.e, active secretion (cholera toxin) decreases lymph flow while passive fluid secretion (increased portal pressure, plasma dilution) is associated with a rise in lymph flow. In the present study, we examined the effects of ricinoleic acid, vasoactive intestinal polypeptide, theophylline, histamine, and human carcinoid serum on lymph flow in autoperfused segments of cat ileum. Local intraarterial infusion of theophylline, vasoactive intestinal polypeptide, or human carcinoid serum caused lymph flow to decrease. However, intraluminal placement of ricinoleic acid or intraarterial infusion of histamine produced significant increases in lymph flow. The results indicate that the fluid secretion associated with vasoactive intestinal polypeptide, theophylline, and carcinoid serum are consistent with an active process while ricinoleic acid and histamine secretions are associated with a passive component.

Animals↗
PubMed1981

Elevated sialyltransferase activity in the intestinal lymph of colchicine-treated rats.

There is a marked increase in sialyltransferase activity (EC 2.4.99.1) in serum and a profound change in the endogenous acceptor property of sialyltransferase in the intestine of colchicine treated rats (Fraser, Ratnam, Collins and Mookerjea, (1980) J. Biol. Chem. 255, 6617-6625). To ascertain the contribution of intestine as a source of this elevated serum enzyme, sialyltransferase and other enzymes activities were measured in intestinal lymph before and after colchicine treatment. There was a 4-fold increase of the enzyme activity in lymph 3 h after treatment. The lymph flow rate, protein concentration and composition as measured by polyacrylamide gel electrophoresis were not affected. The kinetic properties of lymph sialyltransferase (protein and time dependence, pH optima and Km values for the substrate CMP-sialic acid) were essentially unchanged after treatment and were similar to the serum sialyltransferase. Alkaline phosphatase and lactic dehydrogenase activities remained unchanged. Although intestinal lymph sialyltransferase was increased by colchicine, enterectomy did not prevent the rise of serum sialyltransferase suggesting that the intestine is not a major source of the serum enzyme.

Animals↗
PubMed1981

Endoscopic diagnosis of intestinal metaplasia in Canada and Japan.

We carried out comparative studies on chronic atrophic gastritis with accompanying intestinal metaplasia using the methylene blue dye spraying, endoscopic technique on 167 Japanese and 77 Canadian outpatients free of gross stomach disease. In both population samples (Kyoto, Japan and St. John's, Newfoundland) with increasing subject age, the fundic-pyloric (F-P) border shifted cephalad indicating atrophy of the fundic mucosal glands. Japanese subjects, however, showed greater variation in location of the F-P border. The reduction in fundic gland area with aging was followed by intestinal metaplasia, the incidence and severity of which was greater in Japanese than in Canadian outpatients. From these data we conclude that a difference in the gastric mucosa in these two countries may be related to the pathogenesis of gastric cancer.

Adult↗
PubMed1981

Effect of secretin on intestinal lymph flow and composition in the rat.

The effects of natural porcine and synthetic secretin, given by intravenous bolus or infusion, on intestinal lymph flow and protein composition in unanaesthetized rats were studied. Both forms of secretin increased lymph flow and protein output from the lymph fistula; dose-response relationships were determined. No change was observed in protein concentration in lymph or in the relative concentrations of large and small protein molecules during secretin-induced enhanced lymph flow, compared with the basal state. These results are in keeping with an increase in the functional exchange vessel area of the small intestine produced by secretin. It is possible that secretin may play a part in the hyperaemia and augmented intestinal lymph flow which occurs in the post-prandial period.

Animals↗
PubMed1981

Effects of bradykinin on intestinal transcapillary fluid exchange.

Bradykinin (50 micrograms.L-1) increases intestinal lymph flow sixfold when infused intraarterially into the cat ileum. The capillary filtration coefficient and capillary pressure increase and interstitial fluid pressure rises from negative to positive values. A slight increase in lymph:plasma protein concentration occurs with a resulting fall in the transcapillary oncotic pressure gradient. These results indicate that the effect of bradykinin on intestinal lymph flow is attributable, at least in part, to increased capillary pressure, exchange vessel surface area, and a reduction in the effective transcapillary oncotic pressure gradient.

Animals↗
PubMed1979

A chylous mesenteric cyst and a study of its contents.

A case of a patient with a large chylous cyst in the mesentery of the small intestine is presented. After excision of the cyst, the chyle was analyzed with special reference to its protein and lipid content. The composition of the chyle compared with that of intestinal lymph of experimental animals suggests that the fluid in the cyst has undergone concentration in terms of protein.

Adult↗
PubMed1979

Diarrhea and medullary carcinoma of the thyroid.

The authors present the case of a 34-year-old woman with disseminated medullary carcinoma of the thyroid to emphasize the value of calcitonin assay in the diagnosis of this condition despite the absence of a thyroid mass and negative scans. An increased concentration of serum carcino-embryonic antigen was confirmed. The diarrhea associated with the disease did not respond to indomethacin in this patient suggesting that in some cases of medullary carcinoma diarrhea is not due to excessive production of prostaglandins.

Adult↗
PubMed1978

Proteins of ascitic fluid in constrictive pericarditis.

A patient with chronic calcific pericarditis, hepatic congestion, and fibrosis had massive ascites with a protein concentration of 5.1 g/100 ml. This fluid was in all likelihood largely derived from hepatic interstitial fluid. The ascites-serum concentration ratio for several protein species and molecular exclusion chromatography of these fluids suggested two processes may be involved in the transfer of protein from serum to ascites, namely bulk transfer of all species and molecular sieving.

Adolescent↗
PubMed1978

Enhanced intestinal lymph formation during fat absorption: the importance of triglyceride hydrolysis.

The effect of intraduodenal administration of fats was studied in the rat to define the mechanisms responsible for the substantial increase in intestinal lymph flow and protein transport which follows fat ingestion. Triglyceride in the intestinal lumen, protected from hydrolysis, does not appear to enhance intestinal lymph production. Giving both long- and medium-chain fatty acids, however, causes intestinal lymph flow and protein transport to increase in a manner similar to that found after giving triglyceride which is allowed to undergo hydrolysis. Bile by itself does not seem to be responsible for the phenomenon.

Animals↗
PubMed1978

The effect of glucagon on intestinal lymph flow in rats.

Intravenous injection of a bolus of 5 microgram of glucagon to rats with an intestinal lymph fistula produces a marked, transient rise in lymph flow and protein output from the fistula. The effect is presumably the result of brief enhancement of splanchnic blood flow.

Animals↗