Serial voiding urosonography in posterior urethral valve diagnosis and management in pediatric patients. / Urosonografía miccional seriada en el diagnóstico y manejo de las válvulas de uretra posterior en pacientes pediátricos.

OBJECTIVES: Report our experience with the use of contrast-enhanced serial voiding urosonography (SVU) for posterior urethral valve (PUV) patient diagnosis and management. MATERIAL AND METHODS: Descriptive retrospective study in 0- to 14-year-old patients with suspected PUV at SVU performed as a first contrast-enhanced urinary tract test with subsequent cystoscopic study. Variables were analyzed using SPSSv22. RESULTS: 18 patients were studied (median age: 6 months). Most patients (15) presented posterior urethral dilatation (mean diameter: 9.56 mm) and a >2 mm gap between proximal and distal urethra. 13 cases had bladder thickening and 9 had VUR. 15 PUV cases, 1 case of distal urethral mucocele, and 1 case of bladder diverticulum obstructing the urethra were diagnosed. Complete PUV resection was performed in 10 patients (66.6%) at the first cystoscopy. The control SVU detected one case of recurrence due to persistence of posterior urethral dilatation. The recurrence case and the 5 incomplete resection cases were treated with a second cystoscopy and resection. The youngest patients required a third resection and cutting balloon dilatation due to residual stenosis. Mean creatinine levels at diagnosis were 0.28 mg/dl. CONCLUSIONS: Serial voiding urosonography (SVU) is a useful complementary test in pediatric patients with posterior urethral valve. Its dynamic nature and its advantages - absence of irradiation, safety, and high sensitivity - make it an ideal imaging test for PUV diagnosis and follow-up.

OBJETIVOS: Comunicar nuestra experiencia con la utilización de la urosonografía miccional seriada (UMS) para el diagnóstico y manejo de pacientes con válvulas de uretra posterior (VUP). MATERIAL Y METODOS: Estudio retrospectivo descriptivo en pacientes entre 0 a 14 años con sospecha de VUP en UMS realizada como primera prueba contrastada de la vía urinaria y con estudio cistoscópico posterior. Las variables se analizaron utilizando SPSSv22. RESULTADOS: Fueron estudiados 18 pacientes (edad mediana de 6 meses). La mayoría de los pacientes (15) presentaban dilatación de la uretra posterior (diámetro medio de 9,56 mm) y diferencia entre uretra proximal y distal mayor de 2 mm. Trece casos tenían engrosamiento vesical y 9 RVU. Se diagnosticaron 15 casos de VUP, 1 caso de mucocele de uretra distal y 1 divertículo vesical que obstruía uretra. Se consiguió resección completa de las VUP en 10 pacientes (66,6%) en la primera cistoscopia. La UMS de control detectó un caso de resección incompleta por persistencia de dilatación de uretra posterior. Este caso y los 5 conocidos con resección incompleta se sometieron a una segunda cistoscopia y resección. El menor de los pacientes requirió una tercera resección y dilatación con balón de corte por estenosis residual. La creatinina media al diagnóstico fue 0,28 mg/dl. CONCLUSIONES: La urosonografía miccional seriada (UMS) es una prueba complementaria útil en pacientes pediátricos con válvulas de uretra posterior. Su carácter dinámico y ventajas: ausencia de irradiación, seguridad y alta sensibilidad; la convierten en una prueba de imagen ideal para el diagnóstico y seguimiento de VUP.

Voiding urosonography with second-generation contrast as a main tool for examining the upper and lower urinary tract in children. Pilot Study.

INTRODUCTION: In this series, we analyse the diagnostic efficacy of serial voiding urosonography (VUS) with second-generation contrast, combined harmoniously and specifically with contrast technology, in the examination of the urinary tract in children. This examination includes the diagnosis and follow-up for vesicoureteral reflux (VUR) and urethral disorders, mainly those of the posterior urethral valve (PUV). PATIENTS AND METHODS: After obtaining informed consent, a prospective study was conducted using urosonography with second-generation contrast (sulphur hexafluoride microbubbles, SonoVue®) from November 2014 to October 2015 (1 year) in paediatric patients with suspected VUR or PUV impairment. For patients with a high suspicion of VUR and in cases of PUV, we also conducted simultaneous voiding cystourethrography (VCUG). RESULTS: We studied 40 patients (80 renal units) between the ages of 2 months and 13 years (median age, 14 months). The indication for the test was a suspected VUR (36 patients, group A) and PUV follow-up (4 patients, group B). The test was correlated with VCUG in 16 patients (12 cases with high suspicion of VUR in group A and with 4 cases of PUV in group B). The visualisation of the urethra was appropriate in cases of dilation or urethral stricture. For 3 of these patients with bilateral VUR demonstrated in the serial VUS, the VCUG showed only unilateral VUR in 2 of the patients and no VUR in 1 of the patients (κ=.73). DISCUSSION: We have shown that the visualisation of the urethra is no longer a limitation and that serial VUS can be superior to conventional VCUG in diagnosing VUR.

[Utility of urine levels of interleukins in the diagnosis of vesicoureteral reflux: a case-control study in children]. / Utilidad de los niveles urinarios de interleuquinas en el diagnóstico del reflujo vésico-ureteral: estudio de casos y controles en niños.

UNLABELLED: Invasive imaging methods that require catheterization are used for the diagnosis of vesicoureteral reflux. Our aim is to assess the usefulness of interleukin urinary levels for the diagnosis of reflux in children without urinary tract infection. METHODS: Case-control study in children who underwent a voiding cystourethrogram: forty cases diagnosed of reflux and 80 controls. Concentrations of IL-1beta, IL-6 and IL-8 related to creatinine levels (pg/micromol) were determined in urine samples in all. RESULTS: Sixty-two patients were males and fifty-eight females, with a mean age of 2.4 years. Indications for cystography were previous urinary tract infection in 78 cases (65%), prenatal diagnosis in 24 cases (20%) and postnatal diagnosis of uropathy or family history in 18 cases (15.1%). No significant differences were observed between cases and controls in IL-1beta/creatinine and IL-6/creatinine levels. However, IL-8/creatinine levels were almost significant higher in case group (median 3.5 pg/micromol; SD 9.2) than in control group (median 1.54 pg/micromol; SD 3) (P=0.001). The odds ratio was 5.57 (CI95%: 1.51 a 20.60) (X(MH)=2.80; p=0.005). CONCLUSIONS: Urinary levels of IL-8/creatinine are elevated in children with vesicoureteral reflux, even in absence of urinary tract infection. It could be used as a non-invasive marker for detection of subclinical cases of disease.

[Necrotizing entercolitis and intestinal perforation in very low weight premature infants: which is the best surgical option?]. / Enterocolitis necrotizante y perforaciones intestinales en prematuros de muy bajo peso. Cuá1 es la mejor opción quirúrgica?

Necrotizing enterocolitis (NEC) and isolated intestinal perforation (IP) are common diseases in very low birth weight infants (VLBW) and require surgery in 20-40% of cases. We have performed a retrospective review of VLBW infants with NEC or IP who underwent a surgical procedure between 2000 and 2010, either initial laparotomy (group 1), peritoneal drain placement and subsequent laparotomy (group 2) or peritoneal drainage (group 3). Of 487 VLBW infants admitted to our hospital in the last ten years, 80 patients had NEC or IP, out of these, 31% (n=25) were treated surgically. The study population consisted of 14 girls and 11 boys with a mean gestational age of 26+3 weeks and mean birth weight of 801.4 g (range 460 to 1490 g). Pneumoperitoneum was seen in 48% of cases (n=12). Twelve patients underwent initial laparotomy, 10 patients were treated with peritoneal drainage and subsequent laparotomy and in 3 patients a peritoneal drainage was placed. Mean time between drainage and laparotomy was 69.6 hours. Sixty-eight percent of patients had NEC and thirty-two percent were IP. Survival rate was higher in the group who underwent initial laparotomy (p = 0.001) with an overall mortality of 32% (8 deaths). Optimal surgical procedure must be decided upon clinical condition of individual patients. We consider that initial laparotomy should be the treatment option in VLBW infants with intestinal perforation due to NEC or IP.

[Our experience in retroperitoneoscopic total or partial nephrectomies]. / Nuestra experiencia en retroperitoneoscopia para nefrectomías totales y parciales.

The retroperitoneal laparoscopic approach is displacing open surgery and transperitoneal approach for several benign renal conditions. In the past 6 years we have performed 20 procedures, 10 with lateral position and 10 with posterior prone one: 13 total nephrectomies and 7 heminephrectomies in children aged 4,1 years on average. Mean operative time was 200 minutes in partial procedures and 278 in the total ones. Oral feeding was restored to 11,4 hours and average hospital postoperative stay was 1,58 days in total nephrectomies and 2,18 in heminephrectomies. There was no intraoperative bleeding. Complications were two urine leaks, two infections due to residual ureteral stumps and a case of transient hematuria. There were no significant differences between posterior and lateral approaches as to hospital stay, time of onset of oral feeding or complications, although the average operative time was shorter in the posterior approach (mean 170 min, SD 17,3) than in the lateral one (mean 216 min, SD 41) (P=0,024) in total nephrectomies. Retroperitoneoscopy allows a safe access to the kidney and avoids morbidity associated with the transperitoneal access. The posterior approach provides better vascular control, maintains the peritoneum far and allows the procedure with fewer ports, maximizing work space.

[Results of the percutaneous retrograde embolization as the first choice in the treatment of varicocele]. / Resultados de la embolización retrógrada percutánea como primera opción en el tratamiento del varicocele.

There is evidence that early varicocele treatment decreases testicular damage. The minimally invasive techniques such as laparoscopic varicocelectomy, antegrade sclerotherapy and percutaneous retrograde embolisation, are acquiring greater significance in the treatment of this disease. Since 1994, a series of 51 children, aged 7-16 years (mean, 12.9 years), with left-sided varicocele grades 2 (47%) and 3 (53%) were treated in our institution by percutaneous retrograde embolisation using coils. The right basilica vein was the most widely used (70%) followed by the right femoral vein. Seven children (13.7%) had complications: perforation of internal spermatic vein was the most frequent and treated conservatively. No child presented hydrocele after radiological procedures. Embolisation was accomplished succesfully at the first attempt in 35 (68.6%) of the 51 children and in 45 (88.2%) after a second embolisation. The follow-up ranges from 7 months to 5 ? years (mean, 1.8 years). The patients were monitored with clinical and doppler ultrasound examination 3, 6 and 12 months after the treatment. Retrograde embolisation is a safe and efficient minimally invasive treatment for correcting varicoceles in children. We performed retrograde embolisation as first choice of varicocele treatment in children; a second embolisation or conventional surgery for primary failure or late recurrence should be considered.

[Acute thyroiditis and cervical abscesses as manifestations of the pyriform sinus fistulae]. / Tiroiditis agudas y abscesos cervicales como manifestaciones de las fístulas del seno piriforme.

Pyriform sinus fistula is a rare malformation causing recurrent cervical abscesses and acute suppurative thyroiditis, with a low incidence in general, as the thyroid gland is remarkably resistant to infections. The aim of this paper is to describe the clinical data, diagnosis, treatment and evolution of four cases of pyriform sinus fistulas treated at our institution over the last 15-year period. All appeared at the beginning with left laterocervical inflammatory tumours, with radiological signs of acute suppurative thyroiditis in one case and with heterogeneous masses near the isthmus of the thyroid gland in the rest of them. The fistulous tracts were delineated by barium studies and/or fibro-laryngoscopy. The treatment of the acute phase consisted of broad-spectrum antibiotic therapy with an initial incision and drainage procedures. At the end, a subsequent fistulectomy was made. A left hemithyroidectomy was accomplished at two cases. All the patients remained asymptomatic after the treatment except one girl that suffered recurrence seven years later. For a suitable diagnosis a high index of suspicion are necessary. The best therapeutic option is a good delineation and complete excision of the fistulous tract by cervical approach until disconnecting it of its origin at the hypopharynx. In order to avoid recurrences, the resection of the portion of the involved thyroid gland is recommended.

[Acute abdomen caused by infected duodenal duplication]. / Duplicaciones duodenales infectadas como causa de abdomen agudo.

Infected cystic duplications of the duodenum are unusual lesions. We report two cases of duodenal duplications complicated by infection. The literature is reviewed, and the diagnostic modalities and management options for this unusual pathology are discussed.

[Congenital choledochal cyst and laparoscopic techniques]. / Tratamiento quirúrgico del quiste de colédoco mediante cirugía laparoscópica mínimamente invasiva.

The authors present a 5-year-old girl with a congenital choledochal cyst and repeated cholangitis. On laparoscopy, a type I choledochal cyst of Todani classification was confirmed. The cyst was excised laparoscopically. After exteriorization of the small bowel through the umbilical incision, a Roux-en Y anastomosis was performed. Then the bowel was reintroduced into the abdominal cavity and a laparoscopic end-to-side hepaticojejunostomy was carried out. There were not intra or post operative problems. Oral food intake started at 72 hours and the patient was discharged on day 5 without complications and with excellent cosmetic results. We conclude that laparoscopic techniques are an excellent option for the resection of congenital choledochal cyst and hepaticojejunostomy in children.

Oncologic emergencies secondary to advanced colorectal cancer successfully treated with oxaliplatin/5-fluorouracil/leucovorin: report of three cases.

Metastatic/advanced colorectal cancer is considered a resistant disease and oncologic emergencies secondary to advanced disease may be regarded with a nihilistic attitude. The objective of this report is to emphasize the efficacy of the oxaliplatin/5-fluorouracil/leucovorin regimen (FOLFOX-4) in three patients presenting oncologic emergencies secondary to advanced colon cancer. The first case was a 40-year-old man with severe respiratory insufficiency due to massive carcinomatous lymphangitis; subsequently a cecal adenocarcinoma was diagnosed. The patient's conditions became life-threatening and he was admitted to the intensive care unit. The second case was a 41-year-old woman presenting with fever, abdominal mass and pain. Ultrasound and CT-scan revealed two hepatic masses (13 x 15 and 15 x 20 cm), diagnosed as liver metastases from colon cancer. The patient's condition deteriorated with intestinal obstruction secondary to the large left liver mass. The third case was a 58-year-old woman presenting with hepatic mass, fever and weight loss. Ultrasound and CT-scan showed a liver lesion occupying the right lobe (12 x 14 cm). Ultrasonically-guided biopsy and colonoscopy showed liver metastases from cecal cancer. A 5-fluorouracil/leucovorin regimen failed to improve her clinical condition and she had disease progression, inferior vena cava neoplastic thrombosis and right hydronephrosis. All three patients rapidly improved after a few cycles of oxaliplatin-containing chemotherapy. These cases demonstrate that even patients with advanced colorectal cancer presenting with oncologic emergencies and life-threatening conditions can be successfully treated with the FOLFOX-4 regimen.

Acute and chronic captopril, but not prazosin or nifedipine, normalize alterations in adrenergic intracellular Ca2+ handling observed in the mesenteric arterial tree of spontaneously hypertensive rats.

The effect of hypertension and acute (36-h) or chronic (from age 6 to 16 weeks) antihypertensive treatment with prazosin (2 mg kg(-1) per day), nifedipine (50 mg kg(-1) per day), or captopril (50 mg kg(-1) per day) on Ca2+ mobilization due to alpha1-adrenoceptor activation was analyzed in functional studies using arterial rings [four conductance/distributing vessels: aorta, main mesenteric, iliac, and tail arteries and two resistance vessels; first and second small mesenteric artery branches obtained from spontaneously hypertensive rats (SHR, 6 and 16 weeks old) and age-matched Wistar Kyoto rats (WKY)]. Maximal response to noradrenaline in the presence of extracellular Ca2+ is not affected by hypertension or by the antihypertensive treatment. The extracellular Ca2+-independent contractile responses increased with age in iliac, tail, and small mesenteric arteries (SMA) and were further increased in SHR in SMA from both young and adult animals and in the main mesenteric artery of adult SHR. In main mesenteric artery, this increased contraction in SHR was associated with a higher increase in cytosolic [Ca2+] mobilized by noradrenaline without changes in the total stored Ca2+. Acute or chronic treatment with captopril abolished the differences observed between WKY and SHR in the noradrenaline-induced contraction in mesenteric arteries loaded in Ca2+-free medium. In contrast, animals acutely treated with prazosin or chronically treated with either prazosin or nifedipine exhibit the same differences in Ca2+ handling than untreated rats. In conclusion, these differences are not a consequence of increased blood pressure but precede it and can only be normalized by inhibition of the rennin-angiotensin system.

Changes in the expression of tachykinin receptors in the rat uterus during the course of pregnancy.

In the mammalian female reproductive tract, tachykinin neuropeptides, such as substance P (SP), are localized to a population of sensory fibers and their precise physiological role is still unknown. The aim of the present study was to characterize the population of tachykinin receptors in the pregnant rat uterus and to assess their regulation during the course of pregnancy and after delivery. The expression of the tachykinin NK(1) receptor (NK(1)R), the tachykinin NK(2) receptor (NK(2)R), and the tachykinin NK(3) receptor (NK(3)R) in uteri from rats at different stages of pregnancy and on Day 1 postpartum was investigated by using a semiquantitative reverse transcription-polymerase chain reaction. The contractile effect of tachykinin receptor agonists acting selectively on the NK(1)R, the NK(2)R, or the NK(3)R was investigated by conventional organ bath techniques. Serum levels of estrogen and progesterone were measured by RIA. Our data show that the expression and function of NK(1)R and NK(3)R varied along the course of pregnancy and at postpartum. Uterine NK(2)R mRNA levels remain stable during the course of pregnancy and at Day 1 postpartum; and the contractions elicited by activating selectively the NK(2) receptor in the presence of the neutral endopeptidase inhibitor phosphoramidon (1 microM) were similar in early, mid, or late pregnancy. These results show that the expression and function of tachykinin receptors within the uterus vary with reproductive state and length of gestation, supporting a role for tachykinins in pregnancy and/or parturition in the rat.

Mechanism of vascular relaxation by thaligrisine: functional and binding assays.

In the present study we examine the mechanism by which thaligrisine, a bisbenzyltetrahydroisoquinoline alkaloid, inhibits the contractile response of vascular smooth muscle. The work includes functional studies on rat isolated aorta and tail artery precontracted with noradrenaline or KCl. In other experiments rat aorta was precontracted by caffeine in the presence or absence of extracellular Ca2+. In order to assess whether thaligrisine interacts directly with calcium channel binding sites or with alpha-adrenoceptors we examined the effect of the alkaloid on [3H]-(+)-cis diltiazem, [3H]-nitrendipine and [3H]-prazosin binding to cerebral cortical membranes. The functional studies showed that the alkaloid inhibited in a concentration-dependent manner the contractile response induced by depolarization in rat aorta (IC50 = 8.9+/-2.9 microM, n=5) and in tail artery (IC50 = 3.04+/-0.3 microM, n=6) or noradrenaline induced contraction in rat aorta (IC50 = 23.0+/-0.39 microM, n=9) and in tail artery (IC50 = 3.8+/-0.9 microM, n=7). In rat aorta, thaligrisine concentration-dependently inhibited noradrenaline-induced contraction in Ca2+-free solution (IC50 = 13.3 microM, n=18). The alkaloid also relaxed the spontaneous contractile response elicited by extracellular calcium after depletion of noradrenaline-sensitive intracellular stores (IC50 = 7.7 microM, n=4). The radioligand receptor-binding study showed that thaligrisine has higher affinity for [3H]-prazosin than for [3H]-(+)-cis-diltiazem binding sites, with Ki values of 0.048+/-0.007 microM and 1.5+/-1.1 microM respectively. [3H]-nitrendipine binding was not affected by thaligrisine. The present work provides evidence that thaligrisine shows higher affinity for [3H]-prazosin binding site than [3H]-(+)-cis-diltiazem binding sites, in contrast with tetrandrine and isotetrandrine that present similar affinity for both receptors. In functional studies thaligrisine, acted as an alpha1-adrenoceptor antagonist and as a Ca2+ channel blocker, relaxing noradrenaline or KCl-induced contractions in vascular smooth muscle. This compound specifically inhibits the refilling of internal Ca2+-stores sensitive to noradrenaline, by blocking Ca2+-entry through voltage-dependent Ca2+-channels.

The 5-HT and alpha-adrenoceptor antagonist effect of four benzylisoquinoline alkaloids on rat aorta.

The action of four benzylisoquinoline alkaloids (two aporphines-glaucine and apomorphine, a benzylisoquinoline-papaverine and a bisbenzyltetrahydroisoquinoline-antioquine) on 5-HT-induced contraction in rat thoracic aorta has been examined and compared with that of the control drugs: ketanserin, nifedipine, prazosin and phentolamine. The relaxant action on 5-HT-induced contraction was contrasted with that on the contraction induced by noradrenaline and KCl. The results obtained with control drugs show that ketanserin has clear selectivity for 5-HT receptors, whereas prazosin and phentolamine have high selectivity for the alpha1-adrenoceptor and nifedipine seems to have a more potent effect on KCl-induced contraction than on that induced by 5-HT or noradrenaline. The contraction evoked by 5-HT (10 microM) was inhibited in a concentration-dependent manner by all the alkaloids. The order of potency was: papaverine = glaucine > apomorphine > antioquine. Papaverine had a non-specific relaxant action on 5-HT-, noradrenaline- and KCl-induced contraction, antioquine had a weak relaxant action on the agonist assays, and glaucine and apomorphine inhibited noradrenaline- and 5-HT-induced contraction more potently than they inhibited the K+-depolarized response. These results indicate that the aporphines assayed, S-glaucine and R-aporphine, had selective action against agonist (noradrenaline or 5-HT)-induced contraction rather than against KCl-depolarization of rat aorta. In contrast papaverine, a benzylisoquinoline alkaloid, relaxes all agents used non-selectively as could be expected from the lack of specificity that characterizes this alkaloid.

Characterization of tachykinin receptors in the uterus of the oestrogen-primed rat.

1 The aim of our study was to characterize the tachykinin receptor population in the oestrogen-primed rat uterus. For this purpose, we investigated the receptor type(s) responsible for tachykinin-induced contraction of longitudinally-arranged smooth muscle layer. The effects of substance P (SP), neurokinin A (NKA), neurokinin B (NKB) and several of their analogues with well-defined selectivities for tachykinin NK1, NK2 and NK3 receptors were studied and their inhibition by the selective nonpeptide tachykinin receptor antagonists (S)1-(2-[3-(3,4-dichlorophenyl)-1-(3-isopropoxyphenylacetyl)pip eridin-3-yl]ethyl)-4-phenyl- -azoniabicyclo[2.2.2]octane chloride (SR 140333, NK1-selective), (S)-N-methyl-N[4-(4acetylamino-4-phenylpiperidino)-2-(3,4-dichloro phenyl)butyl]benzamide (SR 48968, NK2-selective) and (R)-(N)-(1-(3-(1-benzoyl-3-(3,4-dichlorophenyl)piperidin-3-yl)prop yl)-4-phenylpiperidin-4-yl)-N- methyla-cetamide (SR 142801, NK3-selective) was evaluated. Additionally, expression of tachykinin receptor mRNA was examined by using the reverse transcription-polymerase chain reaction (RT-PCR). 2 SP, NKA, [Nle10]-NKA(4-10), the analogue with selectivity at the tachykinin NK2 receptor type, and NKB elicited concentration-dependent contractions of the rat uterus. The pD2 values were 5.95+/-0.19; 6.73+/-0.21; 7.53+/-0.12 and 5.76+/-0.21, respectively. The selective agonist for the tachykinin NK1 receptor [Sar9Met(O2)11]-SP produced a small phasic response in the nanomolar concentration range. The selective tachykinin NK3 receptor agonist [MePhe7]-NKB failed to induce any significant contraction. 3 In the presence of the neutral endopeptidase inhibitor phosphoramidon (1 microM), the log concentration-response curves to exogenous tachykinins and their analogues were shifted significantly leftwards. The pD2 values were 6.12+/-0.10, 8.04+/-0.07, 7.89+/-0.03 and 6.59+/-0.07 for SP, NKA, [Nle10]-NKA(4-10) and NKB, respectively. In the presence of phosphoramidon (1 microM), [Sar9Met(O2)11]-SP (1 nM - 0.3 microM) induced concentration-dependent contractions of increasing amplitude when only one concentration of drug was applied to each uterine strip and the pD2 value was 7.61+/-0.89. [MePhe7]-NKB induced small, inconsistent contractions and, therefore, a pD2 value could not be calculated. 4 In experiments performed in the presence of phosphoramidon (1 microM), SR 48968 (3 nM - 0.1 microM) caused parallel and rightward shifts in the log concentration-response curves of NKA. The calculated pKB value was 9.16+/-0.08 and the slope of the Schild regression was 1.28+/-0.24. SR 48968 (0.1 microM) also antagonized responses to SP with an apparent pKB value of 7.63+/-0.13. SR 48968 (0.1 microM) inhibited contractions elicited by NKB (1 nM - 3 microM) and [Nle10]-NKA(4-10) (0.1 nM - 3 microM) but had no effect on the response evoked by [Sar9Met(O2)11]-SP (0.1 microM). 5 SR 140333 (0.1 microM) inhibited responses to SP with an apparent pKB value of 7.19+/-0.22. This compound did not significantly affect responses to NKA, [Nle10]-NKA(4-10) and NKB, but suppressed [Sar9Met(O2)11]-SP (0.1 microM)-induced contraction. SR 142801 (0.1 microM) had no effect on responses to natural tachykinins or their analogues. 6 Total RNA was extracted from some of the uteri used in functional studies. RT-PCR assays revealed single bands corresponding to the expected product sizes encoding cDNA for tachykinin NK1 (587 base pairs) and NK2 receptors (491 base pairs) (n=6 different animals). A very low abundance transcript corresponding to the 325 base pairs product expected for the tachykinin NK3 receptor was detected. 7 The present data show that functionally active tachykinin NK1 and NK2 receptors are expressed in the oestrogen-primed rat uterus. The NK2 receptor type seems to be the most important one involved in the contractile responses elicited by tachykinins. NK3 receptors are present in trace amounts and seem not to be involved in tachykinin-induced contractions.

Alpha-adrenoceptor interaction of tetrandrine and isotetrandrine in the rat: functional and binding assays.

The action of 1S,1'S-tetrandrine, a bisbenzyltetrahydroisoquinoline alkaloid, on alpha1-adrenoceptors has been compared with that of its isomer 1R,1'S-isotetrandrine. The work includes binding assays to analyse the affinity of these products for the [3H]prazosin binding site of rat cerebral cortical membranes and functional studies on rat isolated aorta to examine the effects of both alkaloids on intracellular calcium processes related or not to alpha-adrenoceptor activation. A radioligand receptor-binding study showed that both compounds interacted with the alpha1-adrenoceptors displacing [3H]prazosin from the specific binding site. The Ki values (inhibition constants) were 0.69+/-0.12 and 1.6+/-0.4 microM for tetrandrine and isotetrandrine, respectively. The functional studies showed that both alkaloids concentration-dependently inhibited noradrenaline-induced contraction in Ca2+-free solution (IC50 values, i.e. the concentrations needed to induce 50% inhibition, were 252.8 and 174.9 microM for tetrandrine and isotetrandrine, respectively), the spontaneous contractile response elicited by extracellular calcium after depletion of noradrenaline-sensitive intracellular stores (increase in resting tone; IC50 values 11.6 and 19.6 microM for tetrandrine and isotetrandrine, respectively) and the refilling of intracellular Ca2+ stores sensitive to noradrenaline (IC50 values 7.4 and 14.9 microM for tetrandrine and isotetrandrine, respectively). The results show that tetrandrine and isotetrandrine interact with alpha1-adrenoceptors by displacing the [3H]prazosin binding site and that both compounds inhibit mainly the Ca2+-dependent process and have less action on alpha1-adrenoceptors. Tetrandrine is more potent than isotetrandrine.