ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1993.tb01682.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

SUMMARY1. The gene for dipeptidyl carboxypeptidase 1 (angiotensin I‐converting enzyme, kininase II;DCP1), located on chromosome 17q23, has been implicated in hypertension in rats. In humans associations have been found for the insertion allele of a bi‐allelic insertion/deletion polymorphism ofDCP1with hypertension and the deletion allele with myocardial infarction. Other hypertension studies have, however, failed to find a relationship.2. Mathematical predictions based onDCP1association data suggest that high sib‐pair numbers may be needed to achieve statistical significance by this approach, although differences in the severity of hypertension in different study groups could account for the disparate findings.3. No association was found betweenDCP1allele or genotype frequencies and obesity in essential hyperten

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1993.tb01683.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

SUMMARY1. Renin is highly expressed in submandibular gland (SMG) of mouse, which has two genes,Ren‐1dandRen‐2d, but not at all in rat SMG. Differences in nuclear protein binding to renin promoter DNA were, therefore, explored.2. Rat ‐169 to +23 renin DNA formed complexes with both mouse and rat extract, whereas a corresponding fragment of mouseRen‐IdDNA (‐121 to +4) bound with rat extract, but much less so with mouse extract. Rat extract bound a ‐704 to ‐450 fragment of theRen‐1dpromoter. ForRen‐2d‐578 to ‐383 and ‐786 to ‐718 DNA bound with mouse extract and ‐383 to +11 and ‐664 to ‐ 578 DNA bound with rat extract.3. The results support a role for differences in presence or binding of species‐specifictrans‐actingfactors in the differential regulation of the renin gene in SMG of mouse and rat. Strong binding near the rat RNA polymerase II binding site could repress transcription in rat SMG, and binding peculiar to theRet‐2dB2 element might contr

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1993.tb01684.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

SUMMARY1. Erythrocytic sodium‐lithium (Na‐Li) countertransport (CT) was measured in normotensive Maori and non‐Maori byin vitroandin vivomethods to determine its relationship to erythrocytic hypernatraemia previously identified in Maori.2.In vivoandin vitroCT rates were correlated within race and were similar between races. Countertransport rate was correlated with erythrocytic sodium concentration only in Maori.3. The findings suggest the possibility of a genetically determined alteration in CT stoichiometry in

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1993.tb01685.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

SUMMARY1.In vitroshort‐term production of cortisol by dispersed tumour and non‐tumorous adrenal cortical cells was measured with and without added angiotensin II (AII) or adrenocorticotrophin (ACTH) in adrenals removed from five patients with primary aldosteronism.2. Aldosterone‐producing adenomas (APA) were classified as angiotensin responsive (AII‐R) or angiotensin unresponsive (AII‐U) based on pre‐operative behaviourin vivo.3. Cortisol was produced by both tumour and cortexin vitrowithout stimulation, and significantly more cortisol was generated by the cortex.4. Addition of AII significantly increased cortisol production by both tumour and cortex to an equal extent.5. Addition of ACTH also significantly increased cortisol production by both tumour and cortex, but tumours were more responsive than cortex. The response to ACTH exceeded the response to angiotensin in both tumour and cortex.6. There was no obvious difference between AII‐R and AII‐U APA in terms of cort

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1993.tb01686.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

SUMMARY1. Six (12%) out of 52 respondents to newspaper advertisements for antihypertensive drug trials had elevated aldosterone to renin ratio, confirmed by repeated measurement.2. Failure to suppress aldosterone with fludrocortisone acetate administration and oral salt loading confirmed the presence of primary aldosteronism in all six patients.3. Two of the six patients have already had aldosterone‐producing adenomas removed, one has commenced spironolactone, and one has an adrenal mass on computerized tomography but investigation is incomplete.4. None of the six patients with primary aldosteronism had unprovoked hypokalaemia.5. Plasma aldosterone levels did not distinguish those patients with subsequently proven primary aldosteronism from the others. Plasma renin activity (PRA) was a better discriminator, but not as good as the aldosterone to renin ratio.6. The incidence of primary aldosteronism is probably much higher than the 1% currently quoted in texts, with earlier, normokalaemic forms accounting for the majority of case

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1993.tb01687.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

SUMMARY1. Petrosal sinus sampling has been used to establish the source of adrenocorticotropin (ACTH) in ACTH‐dependent Cushing's syndrome. Naloxone, an opioid antagonist, stimulates ACTH secretion, probably via release of endogenous hypothalamic corticotropin releasing hormone (CRH).2. Three patients with hypercortisolism were studied. Two showed suppressed (>50%) urinary‐free cortisol excretion with high‐dose dexamethasone treatment (2 mg every 6h for 2 days), one did not suppress. The patients were subjected to bilateral simultaneous inferior petrosal sinus sampling (BSIPSS) with simultaneous peripheral venous (forearm) samples. Basal (unstimulated) samples were taken and naloxone (125 pg/kg bodyweight) was given intravenously with subsequent simultaneous sampling. Plasma ACTH was measured by radio‐immunoassay (RIA).3. All cases exhibited a marked rise in immunoreactive (IR)‐ACTH levels (pmol/L) after naloxone injection, basal to peak: case 1, left 11.5–22.1, right 9.8 with no rise, peripheral 9.1–9.5; case 2, left 456–863, right 125–501, peripheral 59–82; case 3, left 12.7–13.0, right 277–431, peripheral 12.1–11.7. All results indicate pituitary Cushing's syndrome, with a central to peripheral ratio>2.3:1. Pituitary Cushing's syndrome was confirmed on the results of trans‐sphenoidal pituitary surgery in cases 1 and 3.4. It is suggested that naloxone injection during petrosal sinus sampling in Cushing's syndrome may assist in the diagnosis of ACTH source, by enhancing ACTH release fro

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1993.tb01688.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

SUMMARY1. Ribonucleic acid (RNA) was extracted from two normal human adrenal cortices and from five aldosterone‐producing adenomas (APA).2. The five APA could be categorized, on the basis ofin vivoaldosterone responsiveness to angiotensin infusion and upright posture, into two APA responsive to both stimuli, two responsive only to angiotensin infusion, and one unresponsive to either stimulus.3. RNA was reverse transcribed and coamplified by polymerase chain reaction (PCR) with an internal standard of renin complementary DNA (cDNA) containing a 60 base pair insertion. Renin mRNA in the APA was compared with normal adrenals.4. Renin mRNA was greater than normal in the two APA responsive to both stimuli and less than, or similar to normal, in the two APA responsive only to angiotensin infusion. Renin mRNA was also less than, or similar to normal, in the APA unresponsive to either stimulus.5. These findings support a possible role for adrenal renin in the development and biochemical behaviour of angiotensin‐responsive

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1993.tb01689.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

SUMMARY1. Nineteen out of 47 patients (40%) with confirmed unilateral aldosterone‐producing adenoma (APA) were responsive to low‐dose angiotensin II infusion (AH‐R), as defined by an increase in plasma aldosterone concentration of>50% over basal at 2 ng/kg per min for 60 min.2. Seven to ten days after unilateral adrenalectomy, aldosterone was no longer responsive to angiotensin infusion in AII‐R APA (100%,n =17). Therefore, angiotensin responsiveness resides within the adenoma in AII‐R APA.3. The upright posture test for the differentiation of adenoma from hyperplasia was unreliable for the AII‐R APA (26%), but generally reliable in the angiotensin‐unresponsive subtype, (AH‐U APA, 96%).4. The reported predominance of females in APA was seen in AII‐U APA (68%), but was reversed i

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1993.tb01690.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

SUMMARY1. Twelve healthy volunteers maintained on a 100 mmol/day Na+diet, were given an intravenous infusion of 2L saline (0.9%) between 10.00 and 13.00h on 2 study days at least 1 week apart. Urine collections (90 min) were made from 08.30 to 16.00 h. Either carbidopa 100 mg or indomethacin 50 mg was given orally at 07.45 h on one study day and placebo was given on the other (in random order).2. On the placebo day, saline infusion caused significant decreases in plasma albumin concentration, plasma renin activity (PRA), plasma aldosterone concentration and urinary aldosterone excretion, with 2 to 3‐fold increases in plasma atrial natriuretic peptide (ANP) concentration and urinary dopamine: noradrenaline ratio (DA:NA), whereas mean urinary kallikrein and prostaglandin E2(PGEI) excretion rates were unchanged. Carbidopa decreased urinary DA:NA and indomethacin decreased urinary PGE2excretion, compared with the placebo day. Excretion of sodium (Na+) decreased below baseline in two out of six carbidopa‐treated subjects and in three out of six indomethacin‐treated subjects, but showed little or no change in the remainder.3. These preliminary observations suggest that some subjects in the early phase of natriuresis after an intravenous Na+load can be identified as having prostaglandin‐dependent or dopamine‐dependent mechanisms for Na+

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1993.tb01691.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY