Effects of kallidinogenase on urinary kallikrein excretion and plasma prostanoid concentrations in patients with essential hypertension

Summary The effects of kallidinogenase on urinary kallikrein excretion, plasma immunoreactive prostanoids and platelet aggregation were investigated in patients with essential hypertension. Urinary kallikrein excretion and plasma 6-keto PGF₁ concentration were significantly decreased in these patients. Significant decreases in blood pressure, as well as significant increases of urinary kallikrein excretion and plasma 6-keto PGF₁ concentration after kallidinogenase administration were also observed.     

Age-related differences in the urinary excretion of prostaglandin F2 alpha catabolites in the rat

Tritium-labeled PGF2 alpha was administered i.v. into rats of varying ages (2, 4, 6 weeks and adult). Urine was collected and assayed for radioactive products by thin-layer-chromatography. Results showed a distinctly different urinary profile between the 2-week-old and the adult rat. While the urinary pattern from the 2-week-old rat gave a single less polar product than PGF2 alpha, the pattern from the adult rat gave products more polar than PGF2 alpha. Urine from the 4- and 6-week-old rats gave a mixture of these types of products. These results indicate that some prostaglandin catabolic pathway (likely the omega-oxidative system) is activated in vivo within the 4-6 week postnatal period in the rat.     

Lack of effect of dihydroergotamine on endothelial and smooth muscle cell proliferation and endothelial cell prostanoid production

The most important effect of dihydroergotamine is venoconstriction, but certain metabolic effects and changes in vessel prostanoid activity have also been suggested. In this study endothelial cell production of 6-keto PGF1 alpha and TxB2 was quantitated in vitro. No evidence of altered prostanoid production was noted after incubation with dihydroergotamine (exposure ranging from 5 x 10(-3) to 5 x 10(-7) g/l). Similarly, no effect of dihydroergotamine on the growth rates of endothelial cells or smooth muscle cells in vitro was documented.     

High potassium intake increases the plasma concentration and urinary excretion of vasopressin in the rat

The effect of alterations of dietary potassium intake on the plasma concentration and the urinary excretion of vasopressin was studied in male rats. Ingestion of a high potassium diet resulted in increases in the plasma concentrations of potassium and vasopressin, systolic blood pressure, urine flow, and urinary vasopressin excretion. Ingestion of a low potassium diet had little effect on the plasma vasopressin concentration and systolic blood pressure but caused decreases in the plasma potassium concentration and urinary vasopressin excretion. The results indicate that physiological changes in the plasma potassium concentration or some other consequence of altered dietary potassium intake can affect vasopressin release and excretion.     

High potassium intake increases the plasma concentration and urinary excretion of vasopressin in the rat

Summary The effect of alterations of dietary potassium intake on the plasma concentration and the urinary excretion of vasopressin was studied in male rats. Ingestion of a high potassium diet resulted in increases in the plasma concentrations of potassium and vasopressin, systolic blood pressure, urine flow, and urinary vasopressin excretion. Ingestion of a low potassium diet had little effect on the plasma vasopressin concentration and systolic blood pressure but caused decreases in the plasma potassium concentration and urinary vasopressin excretion. The results indicate that physiological changes in the plasma potassium concentration or some other consequence of altered dietary potassium intake can affect vasopressin release and excretion.     

Relationship between the renal kallikrein activity and the urinary excretion of kallikrein in rats

Summary Adrenalectomy reduces, and sodium depletion increases, both the daily urinary excretion of kallikrein and the kallikrein activity in the renal cortex. These 2 variables were found to correlate significantly in normal, sodium depleted and adrenalectomized rats, thus supporting the view that kallikrein excretion reflects the activity of the enzyme in the kidney.Acknowledgments. This word was supported by the Deutsche Forschungsgemeinschaft. The technical assistance of Mrs G. Breypohl and Ms J. Kopatsch is gratefully acknowledged. Dr M. Marin-Grez was a fellow of the Alexander von Humbodt Foundation and Dr G. Bönner of the Deutsche Forschungsgemeinschaft.     

Potentiating effect of aldosterone on the diuretic action of atrial extract

Summary The typical stimulatory effect of a rat heart atrial extract on urinary water, sodium, potassium and kallikrein excretion is significantly increased by a previous administration of aldosterone (0.5 g/100 g b. wt) in the rat.     

Potentiating effect of aldosterone on the diuretic action of atrial extract

The typical stimulatory effect of a rat heart atrial extract on urinary water, sodium, potassium and kallikrein excretion is significantly increased by a previous administration of aldosterone (0.5 microgram/100 g b. wt) in the rat.     

Hydrolysis of histones by horse urinary kallikreins

Summary Horse urinary kallikrein was shown to hydrolyze histones from calf thymus and chicken nuclei erythrocytes. The hydrolysis is inhibited by benzamidine and hyposulfite but not by soy-bean trypsin inhibitor; horse plasma kallikrein also produces this hydrolysis.Work supported by grants from Projeto BIOQ/FAPESP (São Paulo), FINEP (Rio) and CNPq (Rio).Fellow from CNPq, from Instituto Biológico (São Paulo).     

Luteolytic potency of 16-phenoxy-derivatives of prostaglandin F2 alpha

The binding of 16-phenoxy derivatives of prostaglandin (PG) F2 alpha to rat luteal membranes, and also their abortifacient potency in pregnant rats, have been studied. Competitive binding studies with various PG-analogues were performed in ovaries of juvenile rats pretreated with PMSG and HCG, and in parallel studies the abortifacient potency of these substances was tested in pregnant rats. It was observed that this class of derivatives bound to the PGF2 alpha receptor as well as, or even better than the parent compound PGF2 alpha. Modifications in the carboxyl group at C-1 yielded derivatives with a higher affinity for the receptor, in decreasing order of effectiveness as follows: -COOR greater than COOH greater than OH. The data obtained from the binding studies also compared well with data on the abortifacient potency in pregnant rats. It is concluded that the addition of a phenoxy group to either the lower or upper side chain of PGF2 alpha may augment the binding to the receptor as well as the biological responses induced by the post receptor effect.     

On the mineralocorticoid and hypertensogenic properties of 16beta-hydroxy-dehydroepiandrosterone.

Dosages of either 1 or 2 mg daily of 16beta-hydroxy-dehydroepiandrosterone, given to mononephrectomized, salt-loaded female rats, had no detectable effect upon saline consumption, blood pressure, kallikrein excretion or heart and kidney weight. Its alleged mineralocorticoid properties, as judged by these criteria, were not demonstrable.     

Calcium dobesilate (Doxium) as a prostaglandin synthetase inhibitor in pregnant human myometrium in vitro

This comparative study on the effect of calcium dobesilate and indomethacin on prostaglandin biosynthesis was performed on microsomal fractions of pregnant human myometrium. Both drugs inhibited prostaglandin synthesis, indomethacin being more potent. Calcium dobesilate inhibited, in a dose-dependent manner, the synthesis of 6-oxo-PGF1 alpha, PGF2 alpha, PGE2 and TXB2. Its inhibitory action is comparable to that of etamsylate.     

Increased urinary excretion of cyclic nucleotides in X-linked hypophosphatemic (Hyp) mice

Hyp mice, a model for human X-linked hypophosphatemia, had elevated urinary cyclic AMP, cyclic GMP, and magnesium excretion compared to normal mice. The data suggest a renal origin of the urinary cyclic nucleotides. No significant differences in plasma cyclic AMP and cyclic GMP were observed between genotypes.     

Inhibition of the ureteral contractions induced by rat urine with kallikrein antibodies

Purified urinary kallikrein induces contractions of the rat ureter in vitro. Antibodies against kallikrein block the contractile response of the isolated ureter to rat urine.     

Study of prostaglandin synthesis during anaphylactic shock in guinea pigs]

In guinea pigs actively sensitized with ovalbumin and shocked, we have measured blood histamine and histaminase, pulmonary content in cycli AMP and prostaglandins (PG) E1, E2 and F2alpha. In pulmonary efferent blood, both PGE and PGF are increased. In lung tissue, only PGF2alpha, which are bronchoconstructive mediators, are increased. Th increased level in PG seems to have two origins: first a specific increase, then an increased synthesis secondary to histamine release.     

Differential effects of ethanol on prostaglandin responses of arterial and venous smooth muscles.

The present results, using isolated rat aortic strips and portal vein segments, demonstrate that ethanol, depending upon concentration, can either enhance or attenuate the contractile actions of PGF2alpha on at least 2 different types of vascular smooth muscle. At the very least, the present findings question that the use of ethanol as a solvent when investigating the contractile actions of PG molecules on smooth muscles.     

On the mineralocorticoid and hypertensogenic properties of 16β-Hydroxy-Dehydroepiandrosterone

Summary Dosages of either 1 or 2 mg daily of 16-hydroxy-dehydroepiandrosterone, given to mononephretomized, salt-loaded female rats, had no detectable effect upon saline consumption, blood pressure, kallikrein excretion or heart and kidney weight. Its alleged mineralocorticoid properties, as judged by these criteria, were not demonstrable.This study was supported by a grant No. HL 15319 from the United States Public Health Service.     

Increased urinary excretion of cyclic nucleotides in X-linked hypophosphatemic (Hyp) mice

Summary Hyp mice, a model for human X-linked hypophosphatemia, had elevated urinary cyclic AMP, cyclic GMP, and magnesium excretion compared to normal mice. The data suggest a renal origin of the urinary cyclic nucleotides. No significant differences in plasma cyclic AMP and cyclic GMP were observed between genotypes.This work was supported in part by research grants from The Kroc Foundation and the NIH, RR-09016.     

Inhibition of the ureteral contractions induced by rat urine with kallikrein antibodies

Summary Purified urinary kallikrein induces contractions of the rat ureter in vitro. Antibodies against kallikrein block the contractile response of the isolated ureter to rat urine.This work was supported by the Deutsche Forschungsgemeinschaft (SFB 90). The technical assistance of J. Kopatsch, R. Marpoder and H. Seeger is gratefully acknowledged.     

The influence of furosemide on the renal excretion of chloramphenicol and its metabolites.

Simultaneous administration of chloramphenicol and furosemide (10 mg i.v.) decreased urinary excretion of chloramphenicol but increased the excretion of its metabolites as aryl amines and total nitro compounds. These latter increases were directly related to Na excretion.