Water vapor therapy (Rezum) for lower urinary tract symptoms related to benign prostatic hyperplasia: early results from the first Italian multicentric study.

PURPOSE: Rezum is the latest developed minimally invasive treatment for benign prostatic hyperplasia (BPH). We aimed to carefully assess the functional outcomes of patients treated with Rezum for BPH. METHODS: We prospectively followed 135 consecutive patients treated by Rezum at 5 institutions from June 2019 to August 2020. The International Prostate Symptom Score (IPSS), International Consultation on Incontinence Questionnaire-Short Form (ICIQ-UI SF), the Overactive Bladder Questionnaire-Short Form (OAB-q SF) score, the International Index of Erectile Function (IIEF-5) and questions 9 and 10 to assess ejaculatory dysfunction were recorded. Election criteria were age > 18, no prior prostate interventions, IPSS ≥ 13, post-void residual ≤ 250 mL, prostate volume between 30 and 120 cc. RESULTS: The median operative time was 10.5 (IQR 8.7-15) min. All patients were dismissed few hours after surgery with indwelling urinary catheter that was removed after a median of 7 (IQR 7-10) days. A significantly decrease of IPSS from baseline at first (p = 0.001) and third (p < 0.0001) month after surgery was reported. No difference was reported in terms of ICIQ-UI SF score postoperatively. A mild reduction of the OAB-q SF score was reported at 1 month from surgery (p = 0.06) that turned significant at 3 months postoperatively (p < 0.0001). A slight but statistically significant increase of the IIEF-5 score was reported from baseline at 6 months (p = 0.04). Postoperatively, patients reported a significantly decrease of ejaculatory dysfunction after alpha-blocker interruption. CONCLUSION: Rezum treatment is a feasible minimally invasive option for patients with BPH symptoms and showed optimal early functional outcomes.

Insulin enhances the bradykinin response in L8 rat skeletal myoblasts.

Inhibitors of ACE/kininase II enhance insulin sensitivity, an action that is mediated in part by bradykinin (BK). We investigated whether insulin interacts with the BK receptor signaling to modulate the inositol 1,4,5-trisphosphate (IP3) response to BK in L8 rat skeletal myoblasts. Stimulation of the cultures with BK (10 nmol/l) for 15 s increased IP3 from a basal level of 75.2 +/- 7.6 to 200.2 +/- 15.7 pmol/mg protein. Treatment of the cultures with 1, 2, and 20 nmol/l of insulin for 90 min before adding BK increased IP3 formation by the same BK dose to 328.2 +/- 19, 434.5 +/- 18, and 460.8 +/-21.3 pmol/mg protein, respectively. When wortmannin was administered to inhibit phosphatidylinositol (PI) 3-kinases at lower concentration (1 nmol/l), it increased IP3 formation stimulated by BK only when insulin was present. At a higher concentration (100 nmol/l), wortmannin significantly enhanced BK-induced IP3 formation in the absence of insulin. Genistein and tyrphostin A-23, tyrosine kinase inhibitors, completely reversed the elevated IP3 formation by BK and insulin. The IP3 response to 10 nmol/l BK was 223.3 +/- 11.8 pmol/mg protein in the absence of insulin and 402.2 +/- 12.0 pmol/mg protein in the presence of 2 nmol/l insulin. However, when exposing the cultures to 1 nmol/l genistein or tyrphostin A-23, the IP3 response to BK in the presence of insulin decreased to 211.8 +/- 46.7 and 187.7 +/- 19.9 pmol/mg protein. Tyrphostin A-1, the inactive analog, was ineffective. Exposing the cells to 1 micromol/ 3,4,5-trimethoxybenzoic acid 8-[diethylamino]octyl ester, an intracellular Ca2+ antagonist, did not change the potentiation by insulin. But, exposing them to 0.1 micromol/l n-[6-aminohexyl]-5-chloro-1-naphthalene-sulfonamide, a calmodulin antagonist, resulted in enhanced IP3 response to BK alone to 292.2 +/- 18.5 pmol/mg protein and to BK in the presence of 1, 2, and 20 nmol/l insulin to 488 +/- 22.2, 625.5 +/- 11.6, and 665.2 +/- 15.9 pmol/mg protein, respectively. In conclusion, insulin potentiates BK-induced IP3 production in L8 rat skeletal myoblasts, and this action of insulin involves a tyrosine kinase. Inhibition of PI 3-kinases potentiated BK-induced IP3 formation in the presence of insulin. Calmodulin blocked the action of insulin. These results support a modulatory effect of insulin on the BK signaling system via a tyrosine kinase in L8 rat skeletal myoblasts that results in increased IP3 formation. Because BK release from skeletal muscle increases during contractions, this action of insulin is likely to play a role in the modulation of the excitation-contraction coupling process of the skeletal muscle.

Bradykinin B2 receptors on skeletal muscle are coupled to inositol 1,4,5-trisphosphate formation.

To determine the presence of bradykinin receptors in skeletal muscle, we examined in both displacement and saturation studies the binding of [125I-Tyr8]bradykinin or [3H]bradykinin in three types of skeletal muscle preparations: membrane fractions from guinea pig hindlimb quadriceps, dog semimembranosus and semitendinosus muscles, and L8 rat skeletal muscle myoblasts. Scatchard analysis of [125I-Tyr8]bradykinin x bradykinin competition binding demonstrated specific bradykinin binding of 4.9 and 3.2 fmol/mg protein in dog and guinea pig skeletal muscle preparations, respectively. Unlabeled bradykinin specifically displaced [125I-Tyr8]bradykinin with IC50 values of 36.5 +/- 6 and 118.0 +/- 16.0 pmol/l from dog and guinea pig muscle membranes, respectively. The B2 bradykinin receptor antagonist HOE 140 and the B1 bradykinin receptor antagonist des-Arg9[Leu8]bradykinin displaced the binding of [3H]bradykinin from dog membranes with IC50 values of 0.38 and 217.3 nmol/l, respectively, suggesting that bradykinin binds to a B2-type receptor. In addition, unlabeled bradykinin competed with [3H]bradykinin for binding to dog skeletal muscle membrane preparations in a biphasic manner. To assess whether this represents multiple bradykinin receptor subtypes present in skeletal muscle homogenates or several affinity states of a single binding site, we examined bradykinin receptors on a pure skeletal muscle system, the L8 neonatal rat skeletal muscle myoblast cell line. These myoblasts also contain specific [3H]bradykinin-binding sites with a Bmax of 271 fmol/mg protein and a Kd of 0.83 nmol/l. Competitive agonist binding curves were biphasic (high-affinity IC50 = 3.9 pmol/l, low-affinity IC50 = 22.6 nmol/l) in the absence of guanosine 5'-O-(3-thio-trisphosphate) (GTP gamma S); they shifted to a model of one affinity (8.1 nmol/l) in the presence of GTP gamma S. Because the enzyme neutral endopeptidase 24.11 is an important kininase in skeletal muscle, we examined the effect of the neutral endopeptidase inhibitor phosphoramidon on the binding of bradykinin to dog skeletal muscle membranes. We found that phosphoramidon decreased the apparent Bmax from 7.3 to 5.8 fmol/mg protein. In addition, in this cell line we investigated the action of bradykinin on phosphoinositide hydrolysis. Inositol 1,4,5-trisphosphate (IP3) was measured with a radioreceptor assay. Bradykinin (0.1 nmol/l to 1 mumol/l) induced IP3 formation in a dose-dependent manner (EC50 = 1.42 nmol/l) from a basal level of 72.8 +/- 16 pmol/mg protein to 433 +/- 35.5 at the highest (1 mumol/l) concentration. We conclude that bradykinin B2 receptors are expressed in skeletal muscle. Phosphoinositide hydrolysis upon stimulation of this receptor is an indicator of intracellular signal transduction. Part of the bradykinin binding in skeletal muscle is due to interaction with the enzyme neutral endopeptidase.

Evidence against a role of vasopressin in the maintenance of high blood pressure in mineralocorticoid and renovascular hypertension.

To determine the role of vasopressin in the maintenance of high blood pressure, the antihypertensive effect of the antagonists of the vasopressor effect of vasopressin, [1-deaminopenicillamine, 4-valine, 8-D-arginine] vasopressin (dPVDAVP), and [1-(beta-mercapto-beta, beta-cyclopentamethylenepropionic acid), 4-valine, 8-D-arginine] vasopressin (cyclo dVDAVP), was studied in unanesthetized, nonsurgically stressed rats with adrenal regeneration hypertension, malignant DOCA-salt hypertension, and malignant two-kidney, one clip Goldblatt hypertension. The doses of vasopressin antagonist used blocked the blood pressure (BP) response to vasopressin almost completely, with no changes in the pressor response to norepinephrine and angiotensin II. Administration of the vasopressin antagonists did not induce significant changes in the mean BP in any of the three experimental groups studied. It is suggested that in unanesthetized, nonsurgically stressed rats with adrenal regeneration hypertension, malignant DOCA-salt hypertension, and malignant two-kidney, one clip Goldblatt hypertension, vasopressin does not have a role in the maintenance of high BP.

Immunoreactive glandular kallikrein in plasma during alterations of urinary kallikrein excretion.

To determine whether maneuvers known to modify immunoreactive urinary kallikrein excretion (iUKK) also alter the concentration of immunoreactive glandular kallikrein (iGKK) in plasma, we measured iGKK in the plasma and urine of rats before, at 1 week, and at 3 weeks after induction of two-kidney, one clip hypertension, low sodium intake, and DOCA-salt hypertension. Glandular kallikrein in plasma and urine was measured by radioimmunoassay. Clipping of a renal artery decreased iUKK from 11.7 +/- 0.5 microgram/24 hr/100 g body weight (BW) to 7.8 +/- 0.5 and 8.2 +/- 0.5 at 1 and 3 weeks after surgery without significantly changing iGKK in plasma. The level of iGKK in the plasma did not correlate significantly with iUKK in the clipped group. Low sodium intake significantly increased iUKK, which rose from 6.6 +/- 0.3 microgram/24 hr/100 g BW to 9.6 +/- 0.5 and 13.9 +/- 0.7 after 1 and 3 weeks. In addition, low sodium intake appeared to increase iGKK in plasma, and a significant positive correlation was observed between iUKK and iGKK in plasma in the group on low sodium diet (r = 0.65, p less than 0.01). DOCA-salt treatment increased iUKK significantly from 10.4 +/- 0.6 microgram/24 hr/100 g BW to 17.1 +/- 1.4 and 22.6 +/- 2.3 at 1 and 3 weeks after. The iGKK in plasma increased from 13.8 +/- 0.5 to 15.4 +/- 0.7 ng/ml (p less than 0.05) at 1 week after the DOCA-salt treatment began, but it returned to pretreatment levels 3 weeks later (14.5 +/- 0.7 ng/ml, n.s.).(ABSTRACT TRUNCATED AT 250 WORDS)

Augmented sympathetic response to bradykinin in the diabetic heart before autonomic denervation.

We studied whether diabetes mellitus affects the bradykinin (BK)-induced release of norepinephrine (NE) from rat cardiac sympathetic endings in situ. Three groups were studied. Group A (n=12) was rendered diabetic with streptozotocin (STZ), group B (n=13) received STZ and insulin, and group C (n=14) received citrate buffer only. NPH insulin was given to group B from day 7 after STZ. Atria were paced (3Hz) with rectangular voltage pulses at mechanical threshold intensity (0.15 V/cm). The release of NE was assessed through its effects on contractile force in the presence of atropine (1 micromol/L). Intensifying the field stimulation above the neural threshold ( approximately 0.4 V/cm) produced a graded positive inotropic effect that was due to the release of NE from sympathetic nerve endings. The additional effect of 0.1 micromol/L BK on the force of contraction was determined at half-maximal neural stimulation (ie, at approximately 0.65 V/cm). Then, after washing out BK and lowering the stimulation intensity to mechanical threshold, a cumulative dose-response curve for added NE was generated, allowing the positive inotropic effects of neural stimulation (with or without BK) to be expressed in terms of an equivalent inotropic concentration of added NE ([NE(eq)]). Neural stimulation, in the absence of BK, gave an [NE(eq)] of 32+/-3 nmol/L in group A, 44+/-6 nmol/L in group B, and 37+/-6 nmol/L in group C. BK increased [NE(eq)] by a factor of 6.2+/-0.9 in group A, 4.5+/-0.5 in group B, and 3.7+/-0.3 in group C. This factor was greater in group A than in group C but indistinguishable in groups B and C. Atria from normal and diabetic rats were incubated in (3)[H]NE for 60 minutes. Excess tracer was removed, and atria were stimulated during a series of 1-minute episodes at half-maximal neural stimulation to cause exocytotic (3)[H]NE release. BK augmented (3)[H]NE release in normal (n=4) and in diabetic (n=4) atria. This BK-induced increase of (3)[H]NE overflow (expressed as a fraction of tissue (3)[H]NE radioactivity) was 4 times greater in diabetic than in normal preparations. The response to BK in releasing sympathetic neurotransmitter is augmented in diabetic rats, recovering in a manner dependent on insulin.

Thromboxane A2 mediates the stimulation of inositol 1,4,5-trisphosphate production and intracellular calcium mobilization by bradykinin in neonatal rat ventricular cardiomyocytes.

Bradykinin is a mediator of the protection of myocardium by angiotensin I-converting enzyme/kininase II inhibitors. We reported that the activation of B2 bradykinin receptors in neonatal rat cardiac myocytes in primary culture was followed by hydrolysis of phosphatidylinositol 4,5-bisphosphate and formation of inositol 1,4,5-trisphosphate (IP3). Here we examine the regulation of IP3 formation stimulated by bradykinin. Activation of myocytes with 1 mu/L bradykinin increased IP3 production from 117 +/- 8.3 to 1011 +/- 48.6 pmol/mg protein. Treatment of the cells with 10 mu/L indomethacin or 1 mu/L dexamethasone partially blocked this bradykinin-induced response. Moreover, either U73122, a phospholipase C inhibitor, or (p-amylcinnamoyl) anthranilic acid, a phospholipase A2 inhibitor, blunted the IP3 response to bradykinin. Because thromboxane A2 stimulates inositol bisphosphate metabolism in guinea pig atria, we also investigated the effect of the thromboxane A2 receptor antagonist BM 13177 (1 mu/L), which strongly attenuated the stimulated IP3 production. Since thromboxane A2 appears to partly mediate the IP3 response to bradykinin, we examined the effect of the stable thromboxane A2 mimetic U46619. Control cultures were stimulated more by U46619 than by bradykinin (1629 +/- 14.5 versus 1011 +/- 48.6 pmol IP3/mg protein). This property of U46619 was selectively antagonized by BM 13177. Inhibition of either phospholipase C or phospholipase A2 blunted the IP3 response to U46619. Short-term (30 minutes) activation of protein kinase C with phorbol 12-myristate 13-acetate (10 pmol/L to 1 mu/L) attenuated the IP3 accumulation in response to bradykinin; the effect of phorbol 12-myristate 13-acetate was reversed with 1 mu/L staurosporine, a protein kinase C inhibitor. Treatment with 1 microgram/mL cholera toxin or pertussis toxin for 4 hours amplified the IP3 response to 10 nmol/L bradykinin from 570 +/- 20.0 to 1150 +/- 51.3 and to 1016.7 +/- 21.9 pmol/mg protein. Bradykinin mobilized 9.4% of intracellular calcium stores in cardiomyocytes as assessed by chlortetracycline-based fluorometry, and this effect of bradykinin was blocked by BM 13177 or the B2 bradykinin receptor blocker Hoe 140 by more than 70%. In functional studies, bradykinin (1 mu/L) increased by 12% the twitch contractile force of neonatal rat ventricular strips paced at threshold intensity, but this was unaffected by BM 13177. In conclusion, in cardiomyocytes, bradykinin enhances IP3 production mostly via phospholipase A2 stimulation and thromboxane A2 formation. This prostanoid in turn stimulates its receptor and activates phospholipase C, which then splits phosphatidylinositol 4,5-bisphosphate into IP3 and diacylglycerol. The effect of bradykinin on phospholipase C, via thromboxane A2, is negatively regulated by protein kinase C activation.

Inactivation of endothelin-1 by an enzyme of the vascular endothelial cells.

We previously investigated the inactivation of endothelin-1 by deamidase (lysosomal protective protein), present in many cells, including vascular smooth muscle cells. This enzyme, which we originally purified from human platelets, preferentially hydrolyzes peptides at the C-terminus with hydrophobic amino acids in the P1 or P1' position or both and thereby inactivates endothelin-1, which has a C-terminal sequence of Ile19-Ile20-Trp21-OH. We tested for the presence of deamidase in cultured bovine aortic endothelial cells. The final supernatant of the homogenized cells (S3) cleaved the deamidase substrate dansyl-Phe-Leu-Arg at a rate of 1.3 nmol/min per 10(6) cells at pH 5.5 at 37 degrees C. Endothelin-1 was completely inactivated by the S3 fraction as determined on rat thoracic aorta strips. The major site of inactivation was the Ile20-Trp21 bond, established by high performance liquid chromatography and by amino acid analysis where the main product was des-Trp21-endothelin-1. The hydrolysis of endothelin-1 (5.9 nmol/min per milligram of protein at pH 5.5 at 23 degrees C) by S3 was blocked mainly by inhibitors of deamidase, including diisopropyl fluorophosphate, but not by inhibitors of some other peptidases. This is the first report of a novel pathway of endothelin-1 metabolism in endothelial cells. Thus, endothelial cells, besides being the source of endothelin-1, contain an enzyme that inactivates it.

Are the inotropic and antiarrhythmic effects of bradykinin due to increases in coronary flow?

The purpose of this research was to test whether the positive inotropic and antiarrhythmic effects of bradykinin are due solely to increases in coronary flow. Rat hearts were perfused at constant pressure (75 cm H2O) and temperature (37 degrees C). Coronary flow was measured using an electronic drop counter. Contractile force was assessed using a left ventricular balloon catheter. Bradykinin (10 nmol/L) significantly increased coronary flow by 55 +/- 8% above the control level of 4.8 +/- 0.5 mL/min (n = 20), while force was increased by 23.1 +/- 3% (n = 20). Ramiprilat (10 nmol/L) potentiated the vasodilatory and inotropic responses to 10 nmol/L bradykinin by 58 +/- 8% (n = 5). When hearts were perfused at constant flow, bradykinin no longer produced a positive inotropic effect. Bradykinin, 10 or 100 nmol/L, under these conditions actually caused a negative inotropic effect of -24.8 +/- 5% (n = 8) and -35 +/- 11% (n = 3), respectively. In another 2 groups of hearts, also perfused at constant pressure, reperfusion arrhythmias were elicited after a 20-min period of complete global ischemia. In control hearts, the mean period of fibrillation was 7.3 +/- 1.8 min (n = 10). This period was significantly reduced to 2.7 +/- 0.7 min (n = 10) in hearts receiving 10 nmol/L bradykinin. In untreated hearts, the coronary flow during the reperfusion period increased over the baseline flow by a factor of 1.8 +/- 0.2, and this factor was not significantly effected by bradykinin. These results suggest that only the positive inotropic, but not the antiarrhythmic, action of bradykinin is due to coronary vasodilation.

Attenuation of epinephrine-induced dysrhythmias by bradykinin: role of nitric oxide and prostaglandins.

Cardiac dysrhythmias are common during anesthesia and surgery. An important precipitating factor of clinically relevant arrhythmias is the introoperative use of epinephrine. Bradykinin acts as an endogenous cardioprotective substance because it suppresses ventricular dysrhythmias induced by ischemia. In this study, we investigated whether bradykinin has a protective effect, preventing the development of dysrhythmias after epinephrine infusion in rats. Because kinins are potent stimulators of the release of nitric oxide and prostaglandins from the endothelium, we investigated whether the protective effect of bradykinin is mediated by these 2 autacoids. Male Sprague-Dawley rats anesthetized with sodium pentobarbital had catheters placed into a carotid artery and both jugular veins. Arterial blood pressure and lead II of the electrocardiogram (ECG) were continuously monitored and recorded. After a steady state was achieved, 1 mg/kg enalapril, an inhibitor of angiotensin I-converting enzyme/kininase II, was given intravenously to all groups except the one treated with losartan. Bradykinin was infused at the initial rate of 0.5 microg/kg per min. Cardiac arrhythmia was induced with 7.5 microg/kg epinephrine intravenously. Dysrhythmia was assessed by counting the number of premature ventricular contractions (PVCs), runs of ventricular tachycardia (V Tach), and missing beats during the first minute after epinephrine. In untreated, control rats, epinephrine caused 10.8 +/- 2.7 PVCs, 0.8 +/- 0.2 runs of V tach, and 11.6 +/- 7.4 missing beats/min. In rats pretreated with bradykinin, the same dose of epinephrine elicited 1.2 +/- 0.5 PVCs, no runs of V tach, and 0.4 +/- 0.4 missing beats/min. This beneficial effect of bradykinin was partially reversed by N-nitro-L-arginine methyl ester (L-NAME) or indomethacin, and completely by L-NAME plus indomethacin or icatibant, but it was not affected by des-Arg9[Leu8]-bradykinin. We conclude that bradykinin, acting on the B2 receptor, attenuates epinephrine-induced dysrhythmia via a mechanism that involves the release of NO and prostaglandins. Although the mechanism is not clear, NO and prostaglandins may prevent epinephrine-induced dysrhythmia and protect the myocardium via a direct action on cardiac neurons.

Potentiation of the effects of bradykinin on its receptor in the isolated guinea pig ileum.

Angiotensin I-converting enzyme (ACE/kininase II) inhibitors potentiated guinea pig ileum's isotonic contractions to bradykinin (BK) and its analogues, shifting the BK dose-response curve to the left. ACE inhibitors added at the peak of the contraction immediately enhanced it further (343 +/- 40%), although the ileum inactivated BK slowly (t(1/2) = 12-16 min). Chymotrypsin and cathepsin G also augmented the activity of BK up to three- or four-fold, but in a manner slower than that of ACE inhibitors. The BK B(2) receptor blocker HOE 140 inhibited all effects. Histamine and angiotensin II were not potentiated. ACE inhibitors potentiate BK independent of blocking its inactivation by inducing crosstalk between ACE and the BK B(2) receptor; proteases activate the receptor by different mechanism.

Lack of potent antinociceptive activity by substance P antagonist CP-96,345 in the rat spinal cord.

Substance P (SP) binds to the NK-1 receptor and has been implicated in the transmission of pain as well as in physiological responses such as salivary gland secretion and neurogenic inflammation. Studies in this field have been limited due to the lack of specific antagonists that are not degraded rapidly and are not neurotoxic. However, a recently developed non-peptide SP antagonist, CP-96,345, is specific for the NK-1 receptor. The purpose of this study was to assess the effects of this antagonist on nociception. The tail flick, paw pinch and hot plate tests were used to assess nociception in rats. Following baseline determination of tail skin temperature and analgesiometric tests, the rats received intrathecal injections of various doses of CP-96,345, and pain sensitivity was assessed at several time intervals up to two hours after injection. The ability of CP-96,345 to inhibit SP induced biting and scratching was also assessed. Results from the analgesiometric tests indicated that there were no significant elevations in the latency of tail flick test or the paw pinch thresholds even at 240 micrograms of CP-96,345. The hot plate latency was elevated at the highest dose of antagonist. In addition, there was a significant dose-related elevation in latency on the hot plate test. CP-96,345 also produced a dose-related decrease in tail skin temperature. CP-96,345 did not block SP induced biting and scratching. CP-96,345 and SP were evaluated for their ability to displace 125I-Tyr8-SP from rat spinal cord, brain and submandibular gland membrane fractions. It was found that although the affinity of CP-96,345 was 56 fold lower than that of SP in the brain, the antagonist was nearly as potent as SP in the spinal cord and submandibular gland. The results of this study suggest that, while CP-96,345 binds to the NK-1 receptor in the spinal cord, this receptor is most likely not involved in mediating some types of nociception at the spinal cord level.

Glandular kallikrein in plasma and urine: evaluation of a direct RIA for its determination.

To determine whether there is glandular kallikrein in plasma, untreated as well as acetone-treated and heated-acidified rat plasmas together with rabbit anti-rat urinary kallikrein were used in counterimmunoelectrophoresis. Precipitation bands were observed with untreated and acetone-treated plasma, suggesting that glandular kallikrein is present in plasma. This enzyme, however, cannot be quantified in the untreated plasma by a new direct RIA since kallikrein inhibitors present in plasma appear to interfere with this assay. Destroying the inhibitors by acetone treatment or by heat and acidification of the plasma partially solves this problem. In the second part of the study, this RIA as well as a kininogenase and an esterase assay were used to measure urinary kallikrein in DOCA-salt treated rats and in control rats. There is a significant correlation between urinary kallikrein measured by the direct RIA and by a kininogenase method (r = 0.75, p less than 0.001) in both DOCA-salt treated and in the control rats. Although the results obtained by the direct RIA and an esterase method significantly correlate in the control rats (r = -0.048, p greater than 0.1). This suggests that part of the urinary esterase activity in the Doca-salt rats is due to urinary enzymes other than kallikrein and that the esterase assay is not reliable for the determination of urinary kallikrein in pathological situations. However, the direct RIA and the kininogenase assay are suitable for this purpose.

Release of kallikrein and tonin from the rat submandibular gland.

The interaction of neurotransmitters and hormones with specific receptors on the plasma membranes of cells results in enzyme secretion from exocrine glands. However, the effects of agonists on the release of kallikrein and tonin from the rat submandibular gland have not yet been evaluated systematically. The purpose of the present study was to investigate the effects of norepinephrine, isoproterenol, methacholine, and cholecystokinin on the simultaneous release of kallikrein and tonin from the rat submandibular gland. Submandibular gland slices were incubated in vitro at 37 degrees C in a modified Krebs-Ringer medium containing 0.2% each of glucose and bovine serum albumin and bubbled with a gas mixture of 95% O2 and 5% CO2. Glandular kallikrein and tonin secreted into the incubation medium were determined by specific radioimmunoassays. Norepinephrine at 10(-5) M concentration increased kallikrein secretion from a control value of 7.7 +/- 1.5 to 114.7 +/- 26.9 ng/min/mg tissues (p less than .01), and at 10(-4) M concentration kallikrein secretion increased to 265.9 +/- 58.3 ng/min/mg tissue (p less than .01). Similarly, norepinephrine at 10(-5) M enhanced the release of tonin from a basal rate of 4.4 +/- 0.6 to 57 +/- 14.4 ng/min/mg tissue (p less than .05), and at 10(-4) M the rate increased to 91.3 +/- 20.0 ng/min/mg tissue (p less than .01). In contrast, isoproterenol, methacholine, and cholecystokinin did not increase the secretion of kallikrein or tonin. We conclude that the secretion of kallikrein and tonin from rat submandibular glands upon sympathetic stimulation is mediated through stimulation of alpha-adrenoceptors only.

Effect of sodium restriction and corticosteroids on glandular kallikrein in plasma and in the submandibular gland.

We investigated whether sodium restriction or mineralocorticoid influence the release of submandibular kallikrein into the blood and/or the concentration of kallikrein in glandular tissue. For this we measured submandibular gland blood flow, arterial and submandibular gland venous kallikrein, and kallikrein in glandular homogenates of male Sprague-Dawley rats after one week of either low sodium or deoxycorticosterone acetate (DOCA) treatment. We also studied the effect of dexamethasone on the concentration of kallikrein in gland tissue and peripheral plasma. Kallikrein in plasma and in homogenates was measured by radioimmunoassay. Blood flow was determined by timed collections of venous outflow. Kallikrein release was calculated as the arteriovenous difference in kallikrein times the rate of submandibular gland plasma flow. The concentration of kallikrein in arterial plasma, the basal submandibular kallikrein release into blood, and the concentration of kallikrein in submandibular gland tissue were all higher during low sodium than during normal sodium intake (20.1 +/- 3.6 ng/ml vs 10.7 +/- 0.5, p less than 0.05; 0.40 +/- 0.09 ng/min/100 g bw vs 0.18 +/- 0.02, p less than 0.05, and 81.6 +/- 5.5 micrograms/mg protein vs 65.1 +/- 4.0, p less than 0.05, respectively). In contrast, DOCA treatment did not affect the concentration of kallikrein in arterial plasma, the basal release of kallikrein from the submandibular gland into blood, or the concentration of kallikrein in the gland. Dexamethasone in doses that did not affect the normal growth of the animals had no significant effect on the concentration of kallikrein either in submandibular gland tissue or in peripheral plasma.(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthetic management of toxic epidermal necrolysis: report of three adult cases.

Toxic epidermal necrolysis is a rare but acute life-threatening syndrome in which the epidermis blisters and peels in large sheets. In general, patients with this syndrome are managed as severe second-degree burn patients, but special consideration should be given to mucous membrane involvement that reduces fluid intake and worsens the fluid deficit, systemic involvement that makes these patients hemodynamically unstable, and progression of cutaneous lesions that enhances the risk of infection and sepsis.

Metabolism of bradykinin by peptidases in the lung.

We investigated the release of carboxypeptidase M (CPM), neutral endopeptidase 24.11 (enkephalinase, NEP), and angiotensin I converting enzyme (kininase II, ACE) and their contribution to bradykinin metabolism in the rat lung. The P3, membrane-enriched fraction of the homogenized lung was rich in all three peptidases. The activities of CPM and NEP were high in bronchoalveolar lavage fluid but lower in alveolar macrophages indicating that they originate from other cells present on the alveolar surface. In situ perfusion of rat lung with buffer that contained either deoxycholate or melittin or compound 48/80, produced lung edema. CPM, NEP, and ACE activities were recovered both in edema and perfusate fluid. The level of CPM and NEP was higher in edema fluid whereas, in contrast, more ACE activity was released into the perfusate. To evaluate the effect of peptidase inhibitors on changes in vascular permeability induced by bradykinin in the in situ perfused rat lung we measured the increase in lung weight as an index of increased vascular permeability or edema. Combined inhibition of either ACE plus NEP or ACE plus CPM augmented the effect of a subthreshold dose of bradykinin. Inhibitors of ACE, NEP, or CPM given alone and a combination of NEP plus CPM inhibitors did not enhance the bradykinin effect. Our results indicate that CPM, NEP, and ACE although present on different lung cells, synergistically modulate bradykinin effects. The different ratios of distribution of these enzymes in the perfusate and in edema fluid may not be due only to their presence on different pulmonary cells but also to their different anchoring mechanisms to plasma membranes.(ABSTRACT TRUNCATED AT 250 WORDS)