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Biomedical subjects

F Fyhrquist

Publications and source records attributed to F Fyhrquist.

At least 235 records · Page 13Linked to original sources
PubMed1979

Angiotensin-converting enzyme. II. Serum activity in early and newly diagnosed sarcoidosis.

Serum angiotensin-converting enzyme (ACE) was studied in 51 patients with early or newly diagnosed sarcoidosis. Only 45% of these patients had increased ACE activity when their diagnosis was established, which diminishes the diagnostic value of this enzyme measurement. On the other hand, ACE accurately reflected disease activity, and it proved a useful tool for assessing of need for corticosteroid treatment. Patients with acute sarcoidosis associated with erythema nodosum (EN) had low ACE activity compared with the other patients with active, but less acute disease. Serum ACE was not significantly correlated with blood lymphocytes or the immunoglobulins, but there was a positive correlation between the enzyme and serum lysozyme, which strengthens the hypothesis of both enzymes being produced by the epithelioid cells of sarcoid granulomas.

Adult↗
PubMed1978

Lack of behavioural effects following intraventricular infusion of somatostatin in the conscious goat.

The effect of IV or intracerebroventricular (ICV) administration of somatostatin was studied on the behaviour of conscious goats. The doses of somatostatin infused IV were 100 and 300 microgram for 30 min and 600 microgram for 6 min. The doses infused ICV were 10 and 100 microgram for 30 min and 600 microgram for 6 min. In contrast to earlier reports on experiments with rats ,no behavioral effects whatsoever were seen in goat. IV infusion of 100 to 600 microgram and ICV infusion of 600 microgram of somatostatin caused a difinite reduction in the secretion of insulin and growth hormone, but had no effect on the concentration of blood glucose. The reason why neither IV nor ICV administration of somatostatin had any behavioural effects in the conscious goat, in contrast to the effects in rat, cannot be explained with certainty. This may be due to species specificity, to the amount of somatostatin reaching the central nervous system, or to some metabolic changes in rat but not in goat.

Animals↗
PubMed1978

Urinary cyclic AMP and vasopressin excretion in rat strains selected for their alcohol intake.

Urinary excretion of adenosine 3',5' -cyclic monophosphate (cAMP) and immunoreactive arginine vasopressin (AVP) were investigated after water loading and following ethanol loading in two rat strains selected for their voluntary ethanol intake. After ethanol loading ethanol preferring (AA) rats excreted more cAMP but less AVP than water preferring (ANA) rats. The results suggest that the strain difference in cAMP excretion is of renal origin and is not due to vasopressin or parathormone. Differences in the sympathetic nervous activity may be responsible for the difference in cAMP excretion.

Alcohol Drinking↗
PubMed1978

Inhibition of vasopressin-release during developing hypernatremia and plasma hyperosmolality: an effect of intracerebroventricular glycerol.

In non-hydrated goats prolonged (3 h, 0.02 ml/min) intracerebroventricular (IVT) infusion of 0.35 M glycerol depressed the plasma vasopressin level during the entire infusion period which resulted in a conspicuous water diuresis outlasting the infusion by about 20 min. Since no compensatory drinking occurred during this sustained water diuresis it gradually induced pronounced dehydration (loss of greater than 1 liter of total body water causing 5% increase in plasma [Na+] and osmolality). The same degree of dehydration was in other experiments induced by water deprivation. It then caused a 5-fold increase in plasma vasopressin level. Corresponding IVT infusions of 0.35 M d-glucose depressed plasma vasopressin level only during the first half of the 3 h infusion period. Consequently, the resulting water diuresis was transient and subsided before the glucose infusion was finished. Plasma renin activity increased during the IVT glycerol infusion and during water deprivation, but was largely unaffected by IVT glucose. Both IVT glycerol and glucose decreased renal sodium excretion. The possibility is discussed that the pronounced ability of IVT glycerol to depress the vasopressin release and thirst is not only due to dilution induced reduction of CSF [Na+], but also to an influence of glycerol on choroidal and/or transependymal Na+-transporting mechanisms.

Animals↗
PubMed1978

Transient water diuresis and syndrome of inappropriate antidiuretic hormone secretion (SIADH) induced by forebrain lesions of different location.

Inhibition of ADH-secretion and transient water diuresis was observed as acute effects of radio-frequency lesions in the septal region of goats. The water diuresis was not compensated for by drinking and therefore rapidly induced pronounced hypernatremia and hypovolemia. The development of hypovolemia was accompanied by a rise in plasma renin activity. Lesions of the same kind, but extending into the preoptic region near the medial portion of the supraoptic nuclei induced the inability to excrete excessive water characteristic of SIADH. Determinations of plasma arginine vasopressin suggested that the lesions causing SIADH did not produce any noticeable increase in basic ADH-secretion. The results suggest that impulses from juxtaventricular receptors regulating ADH-release and water intake to a considerable extent are transmitted via the septal region, and that elimination of this impulse traffic is sufficient to turn water balance to the negative side. However, reflex volumetric inhibition of the ADH-secretion does not seem to be mediated by pathways passing through the septal region.

Animals↗
PubMed1978

A study of permanent adipsia induced by medial forebrain lesions.

Cerebral lesions involving most of the anterior wall of the ventricle, and the medial part of the septal region, induced a permanent loss of thirst in two goats. The ventral part of the lamina terminalis remained intact in one of the animals. Pronounced dehydration (10--13% loss of b.wt.) developed during periods (3--7 days) when water supplementation was omitted. Determinations of plasma arginine vasopressin in one of the animals revealed that the dehydration did not cause any significant increase in the secretion of antidiuretic hormone. However, the water deficit induced a considerable rise in plasma renin activity and tachycardia. If anything, the caroitid blood pressure became slightly elevated towards the end of 7 d dehydration periods. The lesions obviously inactivated a cerebral sensory mechanism controlling water balance. It may have been due mainly to destruction of juxtaventricular receptors in the anterior hypothalamic region, but perhaps also to a disruption of afferents from such receptors located posterior to this cerebral level.

Animals↗
PubMed1978

Systemic lupus erythematosus and DNA antibodies in pleural effusions.

The quantity of antibodies to double-stranded DNA (ds-DNA) in 53 pleural effusions from 48 patients was measured by means of a modified Farr technique. In 10 samples, binding of ds-DNA was greater than 5 mg/l (range 6--14 mg/l), five samples being from patients with systemic lupus erythematosus (SLE), four from patients with lung cancer, and one from a patient with pulmonary tuberculosis. After treatment of pleural effusion samples with DNase, there was a marked increase of ds-DNA binding in the SLE group (n = 5), but none in the lung cancer group (n = 7) or in 4 patients with pleural effusions of various origin. In pleural fluid, demonstration of antibodies to ds-DNA and anti-ds-DNA-ds-DNA complexes, unmasked by DNase, may prove valuable when differentiating clinical conditions with pleural effusions.

Antibodies, Antinuclear↗
PubMed1978

Angiotensin-converting enzyme and lysozyme in silicosis and asbestosis.

Serum angiotensin-converting enzyme (ACE) activity and lysozyme (LZM) concentration in 22 silicosis and 18 asbestosis patients were studied. These patients were compared with 57 untreated and 36 treated sarcoidosis patients. In all groups significantly raised ACE and LZM mean values were noted. Untreated sarcoidosis patients had the highest values. Raised ACE activity in silicosis and asbestosis has not been reported before, and weakens the differential diagnostic value of this enzyme determination for sarcoidosis. The similar patterns of increased ACE and LZM mean values in all three diseases suggest that these enzymes have a common source.

Adult↗
PubMed1978

Faster radioimmunoassay of angiotensin I at 37 degrees C.

We applied a 1-h radioimmunoassay incubation at 37 degrees C in determining generated angiotensin I in an assay for plasma renin activity. Under these nonequilibrium conditions, 26% of the 125I-labeled angiotensin I was bound at zero dose of unlabeled angiotensin, as compared to 57% at equilibrium after 18 h at 4 degrees C. Sensitivity and useful range for the standard curve remained unchanged. Blanks were not altered. There was a good (r = .971) correlation between renin values in 120 plasma samples from hypertensive patients as measured with both procedures. With isoelectric focusing, we detected no damage to the labeled angiotensin I during incubation for 1 h at 37 degrees C in the presence of diluted plasma, disodium ethylenediaminetetraacetate, hydroxyquinoline, and neomycin. Analytical recovery of unlabeled angiotensin I added to the assay mixture was 98 +/- 2.3% (mean +/- SD). We conclude that our incubation conditions allow rapid and accurate assay of plasma renin activity to be completed in one working day.

Angiotensin I↗
PubMed1978

Effect of temperature on plasma renin samples.

Plasma renin activity was measured in parallel in Na2EDTA-contained plasma samples after storage at -20, 4, and 24 degrees C, and in the lyophilized state. In peripheral venous plasma from 22 hypertensive patients, the activity (range, 0.08-46.7 microgram/liter per hour) remained stable during three days of storage at 4 degrees C, but decreased to a variable extent when plasma was kept at 24 degrees C: in one day by 9.2%, two days by 25.6%, and three days by 74.0%. Values were the same for samples handled at room temperature and chilled to 4 degrees C within 3 h and parallel samples immediately cooled in an icebath and kept at 4 degrees C. Freezing (-20 degrees C) and thawing of plasma was associated with a 22% mean increase in activity (range, 0-83%). Lyophilization resulted in a smaller increase of plasma renin activity (mean 12%, range 0-46%). Blood for renin analysis need not be cooled immediately, but must be cooled to 4 degrees C within 2-3 h. It then is stabe for at least three days. Freezing or lyophilization appears to be associated with some cold activation of "prorenin."

Blood Specimen Collection↗
PubMed1977

Effect of buffer composition on binding of adenosine 3':5'-cyclic monophosphate by bovine adrenal extracts.

The binding of cyclic [3H] AMP by bovine adrenal extracts was studied in different buffer systems; 50 mM-Tris/HCl, pH 7.5, buffer containing 4mM-EDTA (disodium salt) offered advantages such as low non-specific interference and high binding affinity. 2-Mercaptoethanol decreased, but EDTA and theophylline increased, the specificity of cyclic [3H]AMP binding as expressed by the displacement of cyclic [3H]AMP by a 1000-fold excess of unlabelled cyclic GMP. The study indicated heterogeneity of the binding material. Mg2+-dependent binding may be eliminated in Tris/EDTA buffer. The heterogeneity and the specificity of intracellular cyclic AMP binders and their dependence in environmental factors should be considered in the evaluation of cyclic AMP binding and second-messenger systems.

Adrenal Glands↗
PubMed1977

Renal artery stenosis in hypertensive renal transplant recipients.

Reconstruction of a stenotic renal artery was done on 5 hypertensive renal transplant recipients, all of whom had deterioration of renal function when the stenosis was detected. After reconstruction renal function improved in 4 of the patients. The blood pressure was easier to control in all 5 patients, with 3 becoming normotensive. A high preoperative plasma renin activity returned to normal postoperatively in 4 patients. No recurrences were observed after a followup of more than a year.

Adult↗
PubMed1977

Blood pressure and renin during treatment with pindolol.

Beta-receptor blocking drugs are known to decrease BP and plasma renin activity (PRA) in hypertensive patients. We treated 31 hypertensive patients with the beta-receptor blocking drug, pindolol, for 3 months. During the first month (mean daily dose 10 mg) and the second month (mean daily dose 14.2 mg) BP and PRA decreased. During the third month of pindolol therapy (mean daily dose 19.0 mg) 16 patients had an unexpected rise of BP towards control levels and PRA levels rose, too. The remaining 15 patients maintained a good antihypertensive drug effect and suppression of PRA. Pretreatment PRA was not related to BP reduction. The change in diastolic BP was not significantly related to that in PRA. The results indicate that low doses of pindolol,10-15 mg daily, will suffice in mild essential hypertension. An increasing frequency of partial drug resistance may be a result of unnecessarily high doses of pindolol.

Adult↗
PubMed1977

Effects of ethanol on urinary arginine vasopressin excretion in two rat strains selected for their different ethanol preferences.

The effects of ethanol on urinary excretion of arginine vasopressin (AVP), sodium, and potassium were investigated in two rat strains specially selected for their different alcohol preferences. The alcohol preferring (AA) strain excreted more AVP and the water preferring (ANA) strain more urine and sodium during six hours after ethanol intubation (2.4 g/kg b.w.; 20% v/v). The data is insufficient to establish a causal relationship between differences in water and electrolyte metabolism and voluntary ethanol consumption.

Animals↗
PubMed1977

Inappropriate secretion of antiduretic hormone, hypertension, and hypoplastic corpus callosum.

The threshold of serum osmolality causing release of vasopressin (antidiuretic hormone) was shifted to an abnormally low level (262 mosmol/kg H2O) in a 14-year-old girl with hypertension and signs of hypoplastic corpus callosum. There was a physiologically meaningful control of vasopressin release in response to water restriction and water load. Plasma vasopressin concentrations (range 1.2--11.9 pg/ml) were of the same magnitude as those of healthy adults, being abnormally high only when related to the hypotonicity of serum observed. Plasma concentrations of angiotensin II were higher than expected from the suppressed levels of plasma renin activity. Blood-pressure response to angiotensin II infusion was increased. Resetting of the osmostat and hypertension may both be explained by lesions of the central nervous system.

Adolescent↗