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Biomedical subjects

C Hottenrott

Publications and source records attributed to C Hottenrott.

At least 55 records · Page 3Linked to original sources
PubMed1984

[Biochemical parameters of hepatic ischemia in experimental animals].

It was the aim of this study to define biochemical parameters of hepatic ischemia. In seven dogs portal vein and hepatic artery were occluded subsequently. During this ischemia the lactate concentration in the hepatic veins rose from a basal value of 15 mg% to 57 mg%. Lactate levels measured in portal vein, femoral artery, and femoral vein were significantly lower. Furthermore, hepatic ischemia caused an increase in potassium and glucose levels in the hepatic vein. Primarily, production of lactate by the liver seems to be an appropriate parameter for hepatic ischemia. Measuring lactate metabolism could be used to examine patients with portal hypertension before performing a shunt procedure. By cannulating the umbilical vein it is possible to occlude the portal vein with a balloon catheter. Portal vein occlusion with hepatic vein blood sampling may identify those patients in whom hepatic arterial reserve is inadequate to support portosystemic shunting.

Animals↗
PubMed1984

The influence of autonomous nervous activity on total and regional gastric blood flow.

Using 8 mu radioactive microspheres total and regional gastric blood flow were measured in dogs under electrical splanchnic stimulation (SS), following splanchnicectomy (SE), under electrical stimulation of the vagal truncs (VS) and following truncal vagotomy (VE). The values were compared to controls and were taken while cardiac output (CO) and mean aortic pressure ( AOBP ) were registered. Total GBF was 16 +/- 4 ml/100g/min. in 8 animals. Regional flows were highest in the mucosa of corpus and fundus (35 +/- 7 and 27 +/- 6 ml/100g/min.) and lowest in the seromuscularis (4 +/- 1 ml/100g/min.) SS decreased total GBF to 7 +/- 2 ml/100g/min. and this was due to a most dramatic fall in corpus and fundus mucosal flow by 75%. In contrast SE increased total GBF to 30 +/- 11 and regional corpus mucosal flow achieved 85 +/- 24 ml/100g/min. Blood flow changes under VS were similar to those following SE but were less elevated. In the same manner flow reduction following VE was similar to the changes seen after SS but in average less profound. CO and AOBP increased during SS (less than 30% of control) but were almost the same for SE, VS and VE.

Animals↗
PubMed1984

How to achieve total gastric sympathectomy.

Experimental examinations on acute, stress induced gastric ulcers have shown the outstanding role of the sympathetic innervation in the pathogenesis of this ischemic disease. As reduction of sympathetic tonus resulted in a significant prophylaxis against "stress ulcers", further experimental work was done to achieve total but selective gastric sympathectomy. In a histomorphological study in dogs (Method: Hillarp and Falck in the modification of Heene ) the effects of three different surgical procedures on gastric sympathetic denervation were investigated: 1. Selective proximal vagotomy (= SPV, 8 dogs) 2. SPV and periarterial denervation of the main gastric arteries with severance of the gastrolineal ligament (= PASD , 8 dogs) 3. PASD alone (7 dogs) Selective proximal vagotomy resulted in a sympathetic denervation of major parts of the right site of the fundus and corpus. Following selective proximal vagotomy with periarterial denervation ( PASD ) there was a complete sympathetic denervation of the entire stomach. Only a minimal area of resting sympathetic innervation was observed on the esophago-cardial border when periarterial denervation ( PASD ) was performed alone.

Animals↗
PubMed1983

[Conjugated cholic acid in the portal vein, aorta and hepatic vein in patients with alcohol toxic liver cirrhosis].

In 12 patients with Laennec's cirrhosis conjugated cholic acid was measured by radioimmunoassay simultaneously in the portal vein, the aorta, and the hepatic vein. Furthermore, the concentration was measured for 90 minutes after i. v. injection of cholecystokinin. In the fasting patient the porto-venous extraction ratio was 0.45 (SD 0.23) and the arterio-venous extraction ratio was 0.24 (SD 0,21). 15-30 minutes after cholecystokinin the bile acid concentration significantly increased. In this time the porto-venous extraction ratio rose to 0.71 while the aorto-venous extraction ratio was different. These results agree with the hemodynamics found in cirrhosis. After cholecystokinin the increase in the extraction ratio account for the blood loss by porto venous shunts which corresponds to an increase of the portal compartment.

Adult↗
PubMed1983

[The problem of anastomosis of the large intestine].

Healing problems following surgery of the colo-rectal junction seem to be due primarily to the blood supply of the anastomosis. Radical resections of the draining lymph system (metastatic road) including the dissection of the inferior mesenteric artery in patients with distal colonic cancer may reduce the blood flow to the oral stump of the anastomosis dramatically. In a retrospective analysis, this kind of resection technique will have a much higher incidence in anastomotic stenosis compared to controls without ligation of the artery. By using the electrical knife versus scalpel or scissors a significant higher damage of the colonic wall in animals and increased healing problems of anastomoses can be expected clinically.

Animals↗
PubMed1981

[The effect of normothermic and hypothermic gastric irrigation on blood flow of the canine stomach (author's transl)].

A gastric irrigation by an open naso-gastric tube with ice-solutions is a standard procedure in the management of upper gastrointestinal bleeding. In 6 dogs the effect of an increased intragastric pressure and of gastric cooling upon gastric blood flow was examined, using radioactive microspheres. Filling the stomach with saline solution of 38 degrees C to an intragastric pressure of 15 cm H2O reduces canine gastric blood flow from 21,3 +/- 4,4 ml X 100 g-1 X min-1 to 12,6 +/- 2,9 ml significantly. Probably as a consequence of compression only mucosal blood flow is lowered. Blood flow during local hypothermia (21 degrees C at the outer wall of the stomach) at the same intragastric pressure is 60% less than the control value at empty stomach and 33% less than the value at increased pressure without lowered temperature (p less than 0,01). Blood flow to the muscularis is now reduced too. This may be explained by vasoconstriction. However, local hypothermia causes the stomach wall bleeding time to increase three times (13), whereas irrigation by 38 degrees C fluid doesn't alter the coagulation of blood. An irrigation with high volumes of a fluid with body-temperature, which lowers gastric blood flow without changing coagulation and with an open system, which allows the cleaning of the stomach, seems to be more valuable than local hypothermia by a ballon system.

Animals↗
PubMed1979

[Studies of gastric circulation in the dog, II. Ligation of main arteries (author's transl)].

Following ligation of a single gastric artery total and regional gastric blood flows are measured using radioactive microspheres of 8 mu size. There is no significant influence on total gastric blood flow. Within the depending anatomical region no significant reduction of total wall blood flow can be determined. However, blood flow to the antrum mucosa is reduced to approximately 40% after ligation of any gastric artery. Thus, it can be concluded that ligation or embolisation of a single gastric artery in diffuse gastric bleeding does not necessarily reduce or terminate the bleeding.

Animals↗
PubMed1979

[Studies of gastric circulation in the dog. III. Remaining blood flow in the dissected stomach (author's transl)].

After mobilisation of the stomach for high anastomosis between esophagus and stomach, gastric blood flow is maintained by only one gastric artery. Total and regional gastric blood flows are measured in 13 dogs using the microspheres method after ligation of three main gastric arteries. In any part of the stomach blood flow does not decline below 40% of the initial blood flow. Blood flow to mucosa of corpus and fundus is hardly reduced even after this drastic reduction of total gastric blood flow. Blood flow in the muscle layer of the fundus is reduced to about 38% if supplied only by the right gastroepiploic artery. Different operative procedures of replacements of the esophagus are discussed.

Animals↗
PubMed1979

[Gastric blood flow in animals. I. Normal blood flow (author's transl)].

Total and regional gastric blood flow were measured in 15 dogs under control conditions (mean AOBP 100 mm Hg) using microspheres labelled with different isotopes (125J, 141Ce, 85Str, 46Sc) of 8 mu size. The mucosa in fundus and corpus showed significantly higher blood flow compared to the antrum. There was no difference in the muscular layer for either part of the stomach. It is concluded from these data that differences in regional blood flow in the unstimulated stomach of the dog are related to different energy-demands within the stomach.

Animals↗
PubMed1978

[Experimental aspects of pathogenesis and prophylaxis of gastric stress ulcers (author's transl)].

The prophylactic efficacy of various treatments was examined in porcine haemorrhagic shock [13] by measuring total and regional gastric blood flow with radioactive Microspheres. All 24 animals of the control-group (no treatment) developed extensive haemorrhagic lesions of the stomach. Total gastric blood flow fell almost by 90% during shock. By methods improving the circulation during heamorrhagic shock, a nearly total prevention of gastric stress lesions was possible. After splanchnicectomy (n = 7) and by application of the H2-receptor antagonist Cimetidine (n = 8) total gastric blood flow during haemorrhagic shock fell only by 38% and 44%, respectively, when compared to control values before shock. Only 2 piglets of these both groups developed minor changes, whereas in all others no lesions were seen macroscopically or histologically. Conversely truncal vagotomy (n = 9), which impairs gastric blood flow, had no prophylactic effect on the occurence of gastric mucosal lesions, induced by haemorrhagic shock. -- This study supports the suggestion, that gastric ischaemia due to sympathetic overactivity especially in corpus and fundus of the stomach plays an important role in the pathogenesis of gastric stress lesions. An improvement of gastric blood flow during shock could become a useful treatment in man.

Animals↗
PubMed1978

The role of ischemia in the pathogenesis of stress induced gastric lesions in piglets.

Ten conscious piglets were subjected to hemorrhagic shock for three hours. Nine surviving piglets showed severe stress induced gastric mucosal lesions in the gastric fundus and corpus. Total as well as regional gastric blood flow was measured, 8 micron radioactive microspheres, in the same piglets before--control--and during hemorrhagic shock. Total gastric blood flow fell almost 90 per cent uring shock. There was a significantly higher flow reduction in the mucosa of the corpus and fundus, where almost all of the stress lesions were found. Measurement of blood flow within these lesions demonstrated a fall approximately to zero. Ischemia seems to be an important pathogenetic factor of gastric stress lesions. This may possibly render the gastric mucosa more susceptible to other injurious factors.

Animals↗
PubMed1978

[The effect of vagus and sypathetic nerves on blood flow in the swine stomach].

Porcine gastric blood flow (radioactive microspheres) was studied (aortic blood pressure controlled) under five conditions: control (n = 8), electric stimulation of the splanchnic nerves (n = 8) and the vagus nerves (n = 8), truncal vagotomy (n = 8), and gastric sympathectomy (splanchnicotomy, n = 5). Highly significant increase in corpus mucosa flow after vagal stimulation or gastric sympathectomy is antagonistic to changes after splanchnic stimulation and truncal vagotomyand is often contrary to changes of the antrum mucosa. This might be an explanation fir ischemic gastric lesions (stress ulcer) after stress-induced high sympathetic tone (1, 2) and stress ulcer prophylaxis by gastric sympathectomy (3, 4).

Animals↗
PubMed1978

[Blood flow in the swine stomach in hemorrhagic shock].

In nine conscious piglets, total and regional gastric blood flow was measured (8 microns radioactive microspheres) in the same animals before (control) and at the end of a 3-h hemorrhagic shock period (mean AoBP = 40 mm Hg). Gastric blood flow decreased dramatically (88.4%) during shock. This decrease was most severe in the mucosa of corpus and fundus, where the highest flow was registered during control and where stress lesions are usually found. The reduction in gastric flow was significantly greater than the reduction in cardiac output (45.1%). The disproportional reduction in gastric blood flow may be explained by the high alpha-adrenergic activity of splanchnic organs (2) and by the impediment to liver outflow (1) during hemorrhagic shock.

Animals↗
PubMed1977

[Experiences with the hemorrhagic shock in immature pigs (author's transl)].

In 74 immature pigs a hemorrhagic shock (3 hrs duration: mean arterial pressure 40 mm Hg) was established (NORTON 1972). Following this systemic stress all animals developed stress-lesions of stomach and duodenum. In comparison to other stress-models porcine hemorrhagic shock seems to be qualified to study pathogenesis, prophylaxis and therapy of gastric stress-lesions: Pigs correspond best to humans in their gastro-intestinal physiology, hypotension simulates one of the most important surgical causes of stress complications and stress-lesion produced by this model have a marked similarity to those of humans. In contrast to these advantages there are some problems in using this model: Prompt and dangerous electrolyte imbalance following correction of disturbances in acid base equilibrium; irreversible shock following protracted hypotension (3 hrs). For this reason 19% of all piglets died before (1 animal), during (10 animals) or immediately after shock (3 animals). By careful observation of the mentioned problems, however, this experimental model combines a high incidence of stress-lesions with a low rate of casualities.

Animals↗