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Biomedical subjects

H Woossmann

Publications and source records attributed to H Woossmann.

11 recordsLinked to original sources
PubMed1984

Different behaviour of normotonous and spontaneously hypertensive rats with vitamin D intoxication.

Spontaneously hypertensive rats (SHR) were found to tolerate the consequences of vitamin D intoxication much better than Wistar Kyoto rats (WKY). This is obvious from the 10-fold higher death rate of WKY rats and from the considerable differences of the tissue reactions occurring in the aorta, the cardiac muscle and the arterial vessels between WKY rats and SHR. Thus, myocardial alterations are much rarer in SHR; this holds also for the aorta calcification which is less pronounced in SHR and which is age-dependent in so far as it is almost absent from one year onward. Giant granulomas as a result of vitamin D intoxication were found in juvenile SHR at a time where they would otherwise no yet have occurred at a frequency observed in old untreated SHR. Common to both WKY rats and SHR is the formation of vascular alterations (plasmatic vasculosis) which reveal--though less pronounced with SHR--the angiotoxic action of vitamin D. For these considerable differences in the behaviour of WKY and SHR in vitamin D intoxication the different Ca-binding and transport properties of the arterial plasma membranes should be responsible, which is likely to be due to a defect in the Ca-transport mechanism of the smooth vascular muscle. The importance of these findings for the use of vitamin D intoxication in arteriosclerosis research as well as for studies on the pathogenesis of permeability disorders and alterations of the arterial vascular system is pointed out.

Aging↗
PubMed1984

[Histomorphological findings in the ascending aorta and inferior vena cava following implantation of ultrasonic Doppler flow transducers and pressure transducers in long-term experiments with rabbits and cats].

We investigated the histological changes of the vessel walls of the carotis dextra, the aorta ascendens and the vena cava inferior following implantation of flow- and pressuretransducers of 17 rabbits and 4 cats. Following correct adaptation of the vessel volumen the implantates were all well tolerated over a prolonged period (up to 58 weeks) and encapsulated by connective tissue. The histological processes are descripted in detail and lesions produced by ultrasound are shown.

Animals↗
PubMed1980

[Lightmicroscopic studies of plasma permeability at the blood brain barrier in experimental neurogenic interoreceptive hypertension of the rat (author's transl)].

The plasma permeation with its consequences on the nervous system was studied by means of an experimental neurogenic interoreceptive hypertension model. Out of 30 experimental animals (5 controls) showed 7 cerebral extravasations with blood pressure value ranging from 160--170 mm Hg within 4 and 8 weeks, respectively, as proved by Evans Blue injection or subsequent staining of the plasma with Luxol Fast Blue. The permeation sites were found hood-shaped on arterioles with a diameter of 15--30 micrometers, in multifocal arrangement with a certain preference for the frontal cerebral structures. The cerebral damages proved to be microinfarctions, mostly incompletely anemic necroses and forms of neuronal degeneration. Topical coincidence with extravasations is not always present. Further causal factors of cerebral lesions are discussed.

Animals↗
PubMed1978

[Histological findings at the aorta ascendens after measurement of blood flow with ultrasonic doppler technique in chronic experiments with rabbits (author's transl)].

Following implantation of an ultrasonic transducer in the aortic wall of the rabbit, media destructions and pressure necrosis were ascertained when the transducer was fitted closley around the vessel. When the transducer however was fitted widley around the vessel few departures from the normal structure were registered. After ultrasound stress 0.2--0.5 Watt/cm2 5 Min. per die with a mean exposition at 86.6 days, necrosis of the media and proliferations of the intima were noted in the area of the ultrasound application. When the transducer were not protected this resulted in sharp incisures of the vessels giving undeniable proof of ultrasound damages in spite of the low efficiency. Alltogether the histological findings show, that provided correct methodology vasal measurement of blood is possible in chronic experiments.

Animals↗
PubMed1977

[Changes of activity of alkaline phosphatase at the circulatory system in experimental hypertension of the rat (author's transl)].

Changes of activity of the alkaline phosphatase are investigated in the border of the outer media of vessels in two different models of hypertension (Goldblatt and Carotis-Sinus) in the rat. After onset of hypertension an increase of activity takes place in an area largely overlapping a necrosis of the outer medial region of the aorta. The formation of regenerated tissue leads to a thickening of the adventitia and to a decrease of the activities. Changes of the activities in the peripheral vessels presumably are due to participation of other factors. Indications to this effect are discussed.

Alkaline Phosphatase↗
PubMed1976

[Correlations between hippocampus function and stressed learning and their effect on cerebro-visceral regulation processes].

43 male albino rats were investigated to find out what are the effects of bilateral exclusion of pes hippocampus structures upon the development of arterial hypertension released by learning stress exposure. The following results were obtained: 5 weeks of stress exposure (learning load and heavy learning load) caused disturbances of information-processing events of the central nervous system in all the animals with hippocampal lesions. Systolic blood pressure values, fasting blood sugar values, and adrenal weights fall within the physiological range. The B-cells of the pancreatic islets show hypergranulation. Functional tests of the blood pressure under exercise load, and of blood sugar under glucose load revealed normal reactions in animals with hippocampal lesions. In animals with intact brains the same stress exposure caused pathologic malfunctioning (under learning stress) or even premorbid states. The results being considered in relation to the pathogenesis of arterial hypertension show that the exclusion of circumscribed areas of the hippocampus prevents the development of permanent, stress-induced emotional excitations spreading into the viscerum.

Animals↗