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Biomedical subjects

W von Engelhardt

Publications and source records attributed to W von Engelhardt.

At least 73 records · Page 4Linked to original sources
PubMed1979

[The structure of the gastric mucosa of the llamas (Lama guanocoe and Lama lamae). I. Forestomach].

The mucous membrane of the first and second compartments (ventral regions) as well as of the third compartment of Lama guanacoe and Lama lamae stomach shows tubular glands opening into pits. Below the surface epithelium blood capillaries of the fenestrated type form a regular network, each mesh of which surrounds a gastric pit. From a morphological point of view (thin section and freeze-fracture replicas) the columnar cells of the surface epithelium and those of the pits closest to the capillaries are largely similar to the epithelial cells of the rabbit gallbladder. This similarity suggests that at the level of the columnar cells sodium-dependent water reabsorption occurs. This reabsorption has already been demonstrated in the abovementioned compartments by physiological methods. The surface and foveolae epithelial cells as well as some cells of the tubular glands have a secretory function. Their secretory granules contain mucosubstances, as indicated by light-(PAS- and Alcian blue reactions) and electron microscopic (PA-TCH-Ag-reaction) histochemistry. The secretory granules originate from the Golgi complex which shows a positive histochemical reaction in its innermost sacculi at the electron microscope level. Endocrine cells (s. second part of this investigation) are rare. The mucosal membrane of each muscular lip separating the glandular sacs in the first compartment shows a stratified, not keratinized, squamous epithelium.

Absorption↗
PubMed1977

Effect of exercise on systemic blood pressure and heart rate in horses.

Carotid loops were prepared in 3 horses several months prior to the experiments. Systemic blood pressure was recorded at rest and during exercise by insertion of a plastic cannula into the carotid artery. The pressure transducer was fixed at the neck of the animal. The blood pressure signal was transmitted by telemetry. When the horses were standing under the rider, the following results were obtained: heart rate 38 +/- 5 beats-min-1, systolic pressure 115 +/- 15, disstolic pressure 83 +/- 10, mean pressure 97 +/- 12, and pulse pressure 32 +/- 9 mm Hg. During steady gallop at a mean speed of 548 +/- 90 m-min-1, heart rate rose to 184 +/- 23 beats-min-1, systolic pressure to 205 +/- 23, diastolic pressure to 116 +/- 12, mean pressure to 160 +/- 20 and pulse pressure to 89 +/- 19 mm Hg. These values remained stable throughout the exercise period of 5-6 min. When the horses were exercised at stepwise increasing speed from walk through trot to gallop, both the mean arterial blood pressure and the pulse pressure rose in proportion to the running speed.

Animals↗
PubMed1975

Effect of volatile fatty acids on water and ion absorption from the goat colon.

The absorption of volatile fatty acids (VFA) and the influence of VFA on the net transport of inorganic electrolytes and water were examined in the temporarily isolated colon of the conscious goat. Perfusion of the colon with a solution similar in content to that normally present in the cecal outflow showed that the net absorption of VFA was more rapid than that of any other ion present in the solution. When the VFA were replaced with Cl, the net absorption of Na and water was reduced nearly twofold. Increasing the pH of the solution from 6.0 to 7.4 in the presence of VFA also resulted in a twofold decreased in the net transport of Na and water. Perfusion of the colon with a hypertonic solution resulted in approximately zero net water transport; however, the net absorption of Na and VFA continued at similar rates as before. These results support the concept that the colon primarily conserves solute followed by the passive movement of water. They also demonstrate that VFA are rapidly absorbed from the goat colon and indicate a striking influence of VFA on the net transport of Na and water. The presence of VFA in the large intestine may be important for normal absorptive function.

Animals↗