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The chicken lysozyme gene was inserted into an SV40‐based plasmid vector, and the recombinants were transfected into the human cell lines HeLa and MCF‐7. Correct and efficient transient expression directed by the lysozyme promoter was found in both of these cell lines, as determined by S1 nuclease mapping and Northern blot analysis of the RNAs made. SV40 sequences dramatically enhance the expression of the lysozyme gene. This enhancing effect is only acting in cis and is distance/orientation dependent, since clones containing the lysozyme gene in either orientation produce different amounts of correct lysozyme transcripts. The transfected lysozyme gene was not induced by steroid hormone treatment of the cells.

1. Osmotic diuresis was induced in male Sprague-Dawley rats by a 30% (w/v) mannitol solution injected three times at 15-min intervals. Kallikrein excretion increased for a short period after the first two injections, but, despite marked diuresis, the increment of kallikrein excretion after the second injection was less marked than after the first and no enhanced kallikrein excretion was observed after the third injection of mannitol. 2. Urinary kallikrein excretion correlated only with urinary potassium excretion. No correlation was found with either urine volume or urinary sodium excretion. 3. At the end of the osmotic diuresis kallikrein activity was significantly reduced both in the urine and in the renal cortex. At that time plasma aldosterone concentration was slightly greater in the mannitol-treated than that in the control group, but the difference did not reach statistical significance. 4. In this experiment no relationship was observed between the activity of the renal kallikrein-kinin system and the plasma aldosterone concentration. 5. The transient increase in urinary kallikrein excretion is interpreted as a wash-out effect of renal kallikrein, which is followed by a diminished kallikrein activity in urine and in renal cortex.

The nucleotide sequence was determined for the chicken egg white lysozyme mRNA and for the exons of the gene together with their flanking intron regions. The exon pattern is to some degree related to the structural subdivision of the final protein product. However, the relationship of exons to functional units of the enzyme is better established. Exon 2 codes for amino acids 28-82, which include the catalytically active residues and a cluster of amino acids which bind rings C, D, E, and F of the oligosaccharide substrate. Exon 3 codes for amino acids 82-108, which give additional substrate specificity, determine the cleavage frame for the alternating N-acetylglucosamine/N-acetylmuramic acid chain, and increase the catalytic efficiency of the active center. Exons 1 and 4, respectively, code for translational signal sequences on the mRNA, for the signal peptide of prelysozyme, and for the amino- and carboxy-terminal regions of the enzyme. These regions increase the stability of the molecule but are not directly involved in the catalytic function.

1. In male Wistar rats, three doses of frusemide (0·5, 5·0 and 50·0 mg/kg) were injected subcutaneously. A dose-related increase in urine flow and natriuresis occurred, whereas there was a biphasic response in kallikrein excretion with an initial, dose-related transient increase and a secondary reduction. When the urine losses were replaced by the infusion of 0·9% NaCl solution, the biphasic response of urinary kallikrein excretion was maintained. 2. In all experiments, urinary excretion of kallikrein correlated with the excretion of potassium. Frusemide enhanced the excretion of kinins, which correlated with the urine volume and the natriuresis, but not with kallikrein excretion. 3. In contrast to the initially increased excretion of kallikrein, kallikrein activity in the renal cortex remained unchanged or was even reduced. Kininogen content of the perfused tissue of the renal cortex did not vary throughout the experiment, but decreased markedly in the non-perfused tissue of the cortex 30 min after the injection of frusemide. 4. It is concluded that forced diuresis induced by frusemide causes a ‘wash out’ of renal kallikrein in urine, probably not indicating the true changes in the activity of the renal kallikrein-kinin system within the kidney. Kinin excretion in urine was not correlated with kallikrein excretion but with changes in diuresis. Thus it might be suggested that the renal kallikrein-kinin system could be involved by kinins in the regulation of renal water and sodium excretion as well as of renal plasma flow.

1. Rats were made hypertensive by ligating the aorta between the origins of both renal arteries. Sham-operated animals served as controls. Urinary and renal kallikrein activities, as well as plasma and renal renin activities, were measured 8 and 90 days after surgery. 2. Blood pressure was 155 ± 6 mmHg on day 8 after aortic ligature and 142 ± 6 mmHg on day 90; in controls pressures were 107 ± 3 and 110 ± 5 mmHg respectively. 3. Eight days after aortic ligature, kallikrein activity in the ischaemic kidneys was about 6·5 times, and in the non-ischaemic kidneys almost 2 times, that in controls. After 90 days the kallikrein activity was reduced to one-half of that in the controls in the ischaemic kidneys and it was normal in the contralateral. 4. The urinary kallikrein excretion of hypertensive rats was about one-third of that of the controls at both 8 and 90 days after aortic ligature. 5. The plasma renin activity in hypertensive rats was approximately seven times that in control animals 8 days after aortic ligature and did not differ from the control value after 90 days. Renin activity in the kidneys showed the same pattern as in other models of renovascular hypertension: elevation in the ischaemic kidney and reduction in the non-ischaemic one.

Abstract. In male Sprague-Dawley rats the influence of salt loading (1% NaCl), deoxycorticosterone acetate (2 × 15 mg/kg/day resp. 250 mg/kg sc), corticosterone (2 × 20 mg/kg/day sc) and adrenocorticosterone (0.5 mg/kg/day tetracosactid sc) on the activity of renal kallikrein and renal renin activity was investigated.Salt loading lowered renal kallikrein activity, deoxycorticosterone stimulated its activity and in combination they had no effect on renal kallikrein activity. The time course of kallikrein stimulation by deoxycorticosterone showed no relationship to the escape phenomenon of the kidney from the sodium retaining effect of the mineralocorticoid hormone. Reduction of endogenous mineralcorticoid hormones by adrenalectomy caused a marked reduction of urinary and renal kallikrein activity.Corticosterone suppressed the activity of the renal kallikrein-kinin system at the same time as the reduction in urinary aldosterone excretion. Adrenocorticotrophin caused the same decrease in the activity of renal kallikrein as corticosterone. Urinary aldosterone excretion, however, was significantly stimulated. Thus, the known positive correlation between kallikrein and aldosterone was missing.In all experiments the urinary excretion of kallikrein correlated highly with the kallikrein activity measured in renal cortical tissue. However, no correlation was found between kallikrein and urine volume or urinary excretion of sodium and potassium. In our experiments no relationship between the activity of the renin-angiotensin system and that of the renal kallikrein-kinin system was observed. Furthermore, no clear relationship was found between systemic blood pressure and the activity of the renal kallikrein-kinin system.

The activity of the renal kallikrein-kinin system was investigated in male Brattleboro rats homozygous for hypothalamic diabetes insipidus (DI); LongEvans rats (LE) were taken as controls. In the rats with DI, urinary kallikrein excretion was lower (P< 0.05) than in the LE rats. However, when related to total renal mass or to body weight, there was no difference between the two strains. Kallikrein activity in the renal cortex was similar in the Brattleboro and the LE rats.Antidiuretic hormone (vasopressin tannate) in a dose of 100 mU given once daily for 3 days had no effect on urinary kallikrein excretion in either of the strains. Water deprivation for 24 h resulted, also in both strains, in a similar reduction in urinary kallikrein excretion.The renal kallikrein-kinin system of LE rats and that of DI rats does not principally differ in basic activity, nor in response to the administration of vasopressin, nor to water deprivation.