Immunocytochemical localization of atrial natriuretic peptide in the venae cavae and the pulmonary veins of the rat.

In the present investigation 'atrial natriuretic peptide' (ANP) was localized in striated myocytes of the venae cavae and the pulmonary veins in the rat by the use of immunohistochemical and immunocytochemical staining techniques. ANP was stored in granules which appeared to be morphologically similar to the 'atrial specific granules' (ASG) of the atria. In general, the amount of ASG in the great thoracic veins was less than observed in the atria, and the specific granules appeared to be more evenly distributed throughout the sarcoplasm. However, the presence of ANP-containing specific granules in the venae cavae and the pulmonary veins may suggest participation of these veins in the production and secretion of the hormone.

Presence of atrial natriuretic polypeptide in the pulmonary vein and vena cava.

Striated muscle cells and storage granules observed in the atria were found in main branches of the pulmonary veins and superior and inferior venae cavae of the rat, pig, and ox. The presence of atrial natriuretic polypeptide (ANP) in these veins was examined by reverse-phase high-performance liquid chromatography coupled with a radioimmunoassay for ANP. The veins contained 0.6 to 8.0 ng ANP/mg wet tissue with the major molecular form being gamma-ANP. ANP was detected in the peripheral lung tissue in a small quantity, but was not detected in the pulmonary artery. The identification of gamma-ANP and storage granules stained with an anti-ANP antiserum in the pulmonary vein and vena cava suggest that the veins may participate in regulating volume status, blood pressure, and cardiovascular homeostasis through the release of ANP.

Lack of cytochemically detectable cholesterol in rabbit vena cava endothelial plasma membrane.

The response of rabbit vascular endothelial plasma membranes to the cholesterol-binding agents filipin and tomatin was investigated by freeze-fracture electron microscopy. In both single and double labelling experiments, the endothelial plasma membranes of the posterior vena cava were remarkably resistant to the agents compared with the endothelial plasma membranes of other vessels (aorta, pulmonary artery, and pulmonary and cardiac capillaries). This suggests that vena cava endothelium differs markedly from other endothelia, either by having exceptionally low cholesterol levels in its plasma membranes, or with respect to other membrane properties that influence the reaction to filipin and tomatin.

Childhood familial pheochromocytoma. Conflicting results of localization techniques.

Childhood familial pheochromocytoma was investigated in four patients by abdominal computed tomographic scan, [131I]metaiodobenzylguanidine scan, and vena caval catecholamine sampling. Results conflicted with surgical findings. Computed tomographic scan identified all four adrenal tumors but missed two midline tumors in one patient. [131I]metaiodobenzylguanidine scan identified two of three adrenal tumors but also suggested extra-adrenal tumors not confirmed at operation in two of three patients. Vena caval sampling for catecholamines confirmed all adrenal tumors but suggested additional tumors not verified at operation in two of three patients. All patients are asymptomatic and have normal urinary catecholamines 15 to 51 months after operation. Because of the frequency of multiple tumors in familial pheochromocytoma, different diagnostic techniques were employed. False-positive results were more frequent with [131I]metaiodobenzylguanidine and vena caval sampling. Reinterpretation of the [131I]metaiodobenzylguanidine scans at a later date led to less false-positive interpretation, although the false-negative rate remained unchanged. More pediatric experience with [131I]metaiodobenzylguanidine scans and vena caval sampling in familial pheochromocytoma is needed. Confirmation of tumor and its localization rest with meticulous surgical exploration.

Intermediate filament heterogeneity in normal and hypercholesterolemic rabbit vascular smooth muscle cells.

We have examined the intermediate filament (IF) protein content of vascular smooth muscle (SM) cells from several arteries and veins in rabbits and quantitated the changes which occur in SM cell expression of these proteins in response to cholesterol feeding. Cells from control rabbit arteries expressed 30% of their IF protein as desmin, while veins expressed 50% as desmin. During development of diet-induced atherosclerosis, morphological changes in arterial SM cells in the intima correlate with changes in IF expression. There is a significant increase in total IF protein content, vimentin increased differentially in thoracic aorta and desmin in pulmonary artery. In abdominal aorta both increase equally. Cholesterol feeding also resulted in changes in the expression of subspecies of desmin, vimentin, and actin in the thoracic arch. Although cholesterol feeding did not produce obvious morphological changes in the veins examined, venous SM IF protein expression was also altered. In the vena cava of cholesterol-fed rabbits there was an increase in vimentin expression without the parallel increase in desmin that occurred in the arterial system. These studies show that cholesterol feeding of rabbits induces measurable changes in the amounts of IF proteins in both arterial atherosclerotic lesions and venous SM cells.

Calcitonin gene-related peptide in cardiovascular tissues of the rat.

The distribution of calcitonin gene-related peptide immunoreactivity in the cardiovascular system of the rat was investigated by radioimmunoassay and immunocytochemistry. The nature of the immunoreactivity was studied by gel permeation and high performance liquid chromatography. Immunocytochemistry demonstrated the existence of calcitonin gene-related peptide-containing nerve fibres throughout the cardiovascular system. These were present in all regions of the heart, particularly in association with the coronary arteries, within the papillary muscles and within the sinoatrial and atrioventricular nodes. Calcitonin gene-related peptide-containing fibres were found mainly in the adventitia of the arteries and veins. Calcitonin gene-related peptide concentrations were high in major arteries and veins but comparatively low in the heart, aortic arch and thoracic aorta. Chromatography showed that approximately 70% of the total immunoreactivity was identical to synthetic calcitonin gene-related peptide. Calcitonin gene-related peptide concentrations in the blood vessels of rats treated neonatally with capsaicin were not found to be significantly different from those in control animals although capsaicin caused significant reductions of calcitonin gene-related peptide levels in certain other tissues. The results of this study suggest that calcitonin gene-related peptide-containing fibres are likely to be of importance in the innervation of vascular tissues and raise the possibility that these fibres are different in character from calcitonin gene-related peptide-containing fibres found in other tissues.

Quantitation of type I to type III collagen ratios in small samples of human tendon, blood vessels, and atherosclerotic plaque.

A method is described whereby the ratio of the major interstitial collagens (Types I and III) can be measured in biopsy specimens of human tissue weighing as little as 25 mg. Marker peptides are solubilized from the tissue by digestion with cyanogen bromide. These peptides which are not known to be involved in collagen crosslinking are isolated and quantified by a combination of carboxymethyl-cellulose chromatography and polyacrylamide gel electrophoresis. The peptides used are alpha 1(I)-CB7 and alpha 1(III)-CB5. The use of the method is illustrated by analyzing the collagen type ratio in small specimens of tendon, aorta, and vena cava.

Reversibility of arterial and venous changes in renal hypertensive rats.

The effect of reversal of hypertension on vascular function and composition was investigated in renal-hypertensive rats. The study comprised three groups of rats: 1) 21 male Sprague-Dawley rats with one-kidney, one clip Goldblatt hypertension of 9 weeks' duration; 2) 20 rats with one-kidney, one clip hypertension that underwent removal of renal artery clip (were "unclipped") at 6 weeks of hypertension, 3 weeks prior to the study; and 3) sham-operated normotensive control rats. Venous pressure-volume and arterial pressure-flow relationships were measured at maximal vasodilation (sodium nitroprusside and papaverine) in the denervated, pump-perfused vascular beds of the hindquarters of rats. Anatomically defined segments of the aorta and of the vena cava were removed from rats for water, sodium, and potassium analysis. Hypertension was completely reversed in the "unclipped" rats. Compared to values obtained in normotensive control rats, the water concentration of the aorta and of the vena cava, the potassium concentration of the aorta, and the sodium concentration of the vena cava were increased (p less than 0.05) in rats with one-kidney, one clip hypertension. These changes were reversed in the "unclipped" rats. In contrast, the shift of the venous pressure-volume and of the arterial pressure-flow curves toward the pressure axis at maximal vasodilation in hypertensive rats (p less than 0.02) persisted following reversal of hypertension in the "unclipped" rats (p less than 0.05). In chronic, one-kidney renovascular hypertension, the contribution of vascular wall "water-logging" to increased structural arterial resistance and decreased structural venous capacity appears to be minor.

Abnormal ion and water composition of veins and normotensive arteries in coarctation hypertension in rats.

We examined the water, sodium, and potassium composition of the thoracic aorta, abdominal aorta (plus iliac arteries), and veins (vena cava and portal vein) from rats with aortic coarctation. The aortas of 10 rats (group A) were coarcted above the renal arteries to produce hypertension. Control groups consisted of 10 rats sham-coarcted above and 10 rats coarcted below the renal arteries. In group A rats heart weights and carotid artery pressures were elevated over controls (P less than 0.01), whereas there were no significant differences in femoral arterial pressures. In group A rats both the hypertensive thoracic aorta and the normotensive abdominal aorta contained about 20% more water per unit of wet weight, and about 35% and 60% more sodium and potassium, respectively, per unit of dry weight than did the corresponding portions of aorta from control rats (P less than 0.01). In group A rats water (P less than 0.01), sodium (P less than 0.02), and potassium (P less than 0.05) contents of veins also were increased. There were no significant correlations between level of carotid arterial pressure and magnitude of changes in arterial and venous composition, nor were there significant differences between the magnitude of changes in the normotensive and hypertensive portions of the aorta. These results indicate that in rats abnormalities in vascular wall salt and water content are not necessarily a direct effect of the elevated pressure in hypertension.

[Examination of the organs in the upper abdomen with ultra sound (author's transl)]. / Ultraschalluntersuchungen an den Organen des Oberbauchs Teil I

Ultrasonography is a harmless reproducibel technique with its own specific indications, an established part of clinical diagnosis in obstetrics, gynecology, ophthalmology, neurology and cardiology. Investigations on the organs of the upper abdomen have greatly extended the indications. Interpreting the sonograms requires experience in providing and evaluating the picture. In part I of this paper normal ultrasonic findings on liver, pancreas, spleen and kidneys are shown and explained on the basis of the physical characteristics of ultrasound techniques and the various ultrasoundtopographic data. This echographic normal anatomy of the organs mentioned enables us to understand pathologic changes shown in part II. An attempt is also made to allocate and evaluate ultrasonography among other diagnostic techniques.