Search PubMed⌕ Search

Biomedical subjects

H Losse

Publications and source records attributed to H Losse.

At least 37 records · Page 2Linked to original sources
PubMed1985

Influence of low and high cadmium diet in normotensive and hypertensive SH-rats.

Normotensive and SH-rats (Münster strain) were fed a cadmium-rich, normal or cadmium-poor diet. The blood pressure was slightly increased in normotensive rats after feeding a cadmium-rich diet and decreased after a cadmium-poor diet. In contrast, in SH-rats blood pressure was decreased after a cadmium-rich and increased after a cadmium-poor diet. This behavior of the blood pressure corresponded with the intra-erythrocytic Ca2+ activities. Whereas the calcium activities increased in the normotensive group after a cadmium-rich diet, the calcium activities decreased in the SH-group after cadmium feeding. It should be pointed out that normally the calcium activities were found to be elevated in SH-rats. Thus, cadmium feeding here had the same effect as a calcium antagonist.

Animals↗
PubMed1985

The evaluation of tissue Ca2+ by proton-induced x-ray emission in the arteries of spontaneously hypertensive and normotensive rats.

Numerous investigations have shown that Ca2+ plays a critical role in the pathogenesis of hypertension. The intracellular Ca2+ measurements were mainly carried out with Ca2+ selective electrodes. In the present study the particle-induced x-ray emission (PIXE) was used for investigating the Ca2+ distribution of arterial smooth muscle of spontaneously hypertensive and normotensive rats. PIXE yields a correlation of the Ca2+ distribution with the morphological structure of the arterial muscle. The Ca2+ content of the aortic wall of six spontaneously hypertensive and four normotensive rats was investigated. The results demonstrate that the tissue Ca2+ measurements found mainly in the smooth muscle containing tunica media of hypertensive rats are much higher (3105 micrograms Ca2+/g tissue +/- 569 micrograms Ca2+/g tissue) than of normotensive rats (2031 micrograms Ca2+/g tissue +/- 478 micrograms Ca2+/g tissue).

Animals↗
PubMed1985

Humoral factors in the pathogenesis of primary hypertension.

In 42 spontaneously hypertensive rats of the Münster strain either parabiosis or cross circulation with normotensive Wistar Kyoto rats was performed. Cross circulation was made through the common carotid arteries and external jugular veins using a peristaltic pump. In parabiosis and in cross circulation experiments hypertension was transmitted from the spontaneously hypertensive rats to normotensive rats. Nephrectomy or adrenalectomy in the spontaneously hypertensive rat before cross circulation abolished this effect. After volume depletion in the hypertensive animals hypertension was not transmitted either. It is concluded that humoral factors causing vasoconstriction play an essential role in the development of hypertension in the spontaneously hypertensive rat.

Adrenal Glands↗
PubMed1984

Assessment of magnesium and aluminum in erythrocytes by the laser microprobe mass analyzer (LAMMA).

The erythrocyte magnesium content was determined using two different analytical systems (atomic absorption spectrometry and the laser microprobe mass analyzer) with specimens from 18 patients with normal renal function and from 10 patients with chronic renal insufficiency. There was a good correlation (r = 0.73) between the two analytical systems. Additionally, the laser microprobe mass analyzer was used to determine the aluminum content of plasma and erythrocytes in specimens from patients who ingested moderate quantities of aluminum hydroxide for several months. Results showed a significant elevation of the plasma aluminum concentration, but a normal erythrocyte aluminum content. The laser microprobe mass analyzer may be useful in studies of mineral metabolism in humans.

Adult↗
PubMed1984

Intracellular sodium and calcium in vascular smooth muscle of spontaneously hypertensive rats.

Intracellular Na+ and Ca2+ activities in arterial smooth muscle cells and red blood cells from normotensive and spontaneously hypertensive rats were measured by ion-selective electrodes. In red blood cells and aortic smooth muscle cells from spontaneously hypertensive rats examined immediately after isolation, intracellular Na+ and Ca2+ activities were elevated. In aortic smooth muscle cells from spontaneously hypertensive rats, which had been cultured in artificial medium for 10-14 days, intracellular Na+ activity, but not intracellular Ca2+ activity, was elevated. From these observations it is concluded that (a) increased intracellular Na+ activity is associated with a genetic disposition to hypertension, whereas humoral factors are necessary for intracellular Ca2+ activity to be elevated; and (b) the electrolyte abnormalities in red blood cells from spontaneously hypertensive rats reflect concomitant changes in arterial smooth muscle, so that the findings in red blood cells can be regarded as reliable indicators of a generalized defect in cellular electrolyte metabolism.

Animals↗
PubMed1984

Intracellular electrolytes and hormonal parameters during weight reduction.

The mechanisms of the blood pressure lowering effect of weight reduction have not yet been fully elucidated. In this study the intracellular electrolyte composition and hormonal parameters were monitored in 12 obese subjects during a 10-day diet with 800 kcal/day. A decrease in intracellular free Na+ (p less than 0.05) and Mg2+ (p less than 0.01) and in total intracellular K+ (p less than 0.05) was observed. Furthermore, plasma aldosterone and renin activity (p less than 0.05) increased, probably due to a moderate simultaneous salt restriction. There was also an increase in plasma PGI2 concentration (p less than 0.05). The observed decrease in intracellular free Na+ may be caused by salt restriction. The decrease in intracellular K+ and free Mg2+ may be induced by hormonal factors, e.g. an altered insulin secretion. Possible causes for the known hemodynamic effects of weight reduction are the diminution of intracellular Na+ and the increase in plasma PGI2.

Adult↗
PubMed1984

Intracellular electrolytes during antihypertensive treatment with a loop diuretic.

The effect of the loop diuretic, piretanide (12 mg/day on blood pressure and intracellular electrolyte composition in red blood cells during a six-week treatment period was studied in 14 previously untreated essential hypertensive patients. Blood pressure fell continuously during the six weeks, intracellular Na+ activity in red blood cells increased slightly (P less than 0.05), and there was a marked decrease in intracellular Ca2+ activity (P less than 0.01). Intracellular K+ concentration was not altered. It is concluded therefore, that intracellular free Na+ does not correlate with the actual blood pressure, whereas the fall in blood pressure is associated with a decrease in intracellular free Ca2+, suggesting that intracellular free Ca2+ is involved in the regulation of vascular tone.

Adult↗
PubMed1984

Intracellular calcium in essential hypertension. A parameter for assessing effective antihypertensive treatment.

The effects of the loop diuretic piretanide on blood pressure and intra-erythrocytic free Na+ and Ca2+ were examined in 14 essential hypertensives. Intra-erythrocytic Ca2+ activity was found to decrease (P less than 0.01) and Na+ activity to increase (P less than 0.05). In spontaneously hypertensive rats (SHRs) hypovolaemia abolished the humoral transmission of hypertension to normotensive rats. Therefore the decrease in intracellular Ca2+, which may be responsible for the diminished vascular tone under diuretic treatment, could be mediated by a suppression of humoral factors due to diuretic-induced hypovolaemia.

Adult↗
PubMed1984

Role of kidney and adrenals in the humoral pathogenesis of primary hypertension.

In 18 spontaneously hypertensive rats (SHR) of the Münster strain the circulation was connected to that of normotensive animals using the carotid arteries and external jugular veins. The circulations were mixed by a peristaltic pump. In this model the normotensive rats were made hypertensive after a 10-min cross-perfusion cross unidentified humoral factors causing vasoconstriction play an essential role for the development of hypertension in SHRs.

Adrenal Glands↗
PubMed1983

Obesity, hypertension and intracellular electrolytes.

Intracellular activities of sodium and calcium were determined in red cells of patients with obesity. Compared to normal people mean intracellular sodium and calcium were higher in obese patients. However, increased intracellular sodium and calcium could only be observed in those patients with obesity suffering from hypertension or showing a familial disposition to hypertension. In contrast there was no difference in intracellular sodium and calcium between obese normotensives lacking a familial disposition to hypertension and normal people. Thus, our results suggest, that the observed variations in intracellular sodium and calcium in obesity are due to an enhanced blood pressure or a familial disposition to hypertension and not specific for obesity.

Calcium↗
PubMed1983

Intracellular Na+ and Ca2+ in aortic smooth muscle cells after enzymatic isolation in spontaneously hypertensive rats.

In aortic smooth muscle cells from spontaneously hypertensive and normotensive rats, which were separated from the blood vessels by enzymatic digestion, intracellular Na+ and Ca2+ activities were measured. The determinations were made by ion-selective electrodes. In smooth muscle cells from spontaneously hypertensive rats intracellular Na+ and Ca2+ activities were elevated as compared to cells from normotensive rats (P less than 0.001 for Na+ and P less than 0.01 for Ca2+). Since in cultured aortic smooth muscle cells from spontaneously hypertensive rats intracellular Ca2+ is known to be not significantly increased, primarily humoral factors may account for the changes in intracellular Ca2+ reported.

Animals↗
PubMed1983

Potassium load in spontaneously hypertensive rats. Effects on blood pressure, renin-angiotensin, aldosterone, and intracellular electrolytes.

To study the mechanisms by which K+ influences vascular tone in hypertension, spontaneously hypertensive and normotensive rats were examined during an oral K+ load. There was a marked decrease in blood pressure in spontaneously hypertensive but not in normotensive rats. Intraerythrocytic K+ concentration and activity increased in normotensive but not in spontaneously hypertensive rats. Intraerythrocytic Na+ concentration and activity declined in both strains, the decrease in Na+ activity being more prominent in spontaneously hypertensive rats (P less than 0.05). Intraerythrocytic Ca2+ activity decreased in spontaneously hypertensive rats (P less than 0.01) but not in normotensive rats. In both strains plasma aldosterone concentration increased during K+ load, the plasma renin activity being suppressed. The basal levels of plasma aldosterone in spontaneously hypertensive rats exceeded those in normotensive rats. It is concluded that intraerythrocytic Ca2+, and to a lesser extent Na+, correlate best with the blood pressure changes. These ionic changes may be mediated by hormonal factors. The significance of the elevated plasma aldosterone levels has not yet been entirely clarified.

Aldosterone↗
PubMed1983

Side effects of diuretics.

Diuretics are amongst the most widely used drugs. Fortunately enough, there are rather few clinically relevant side effects. The following side effects are discussed in this paper: disturbances of electrolyte, acid-base- and water balance, metabolic changes (uric-acid, carbohydrate-metabolism, lipid metabolism), unspecific side effects and drug interactions. Finally the prevention of side reactions of diuretics is briefly mentioned.

Calcium↗