Cough associated with the use of captopril.

Captopril is an orally active angiotensin-converting enzyme inhibitor that has been widely used in treating hypertension. We present a case of cough associated with captopril treatment in a patient with essential hypertension.

Predisposing factors for the development of malignant essential hypertension.

To clarify predisposing factors for malignant hypertension, we retrospectively investigated the histories of 39 patients with malignant hypertension and 39 patients with benign hypertension. Between the malignant and benign groups, there was a statistically significant difference in blood pressure but not in age when hypertension was first noticed. The number of patients who had discontinued drug treatment was significantly greater in the malignant group (19; 49%) than in the benign group (11; 28%). Insufficient sleep, overwork, and/or mental burden of long duration were factors noticed within one year before the occurrence of the malignant phase in 11 (37%) of the 30 patients in that group in whom this information was available. Patients in the malignant group tended to belong to a lower social class. These results suggest that severe hypertension from an early phase, interruption of drug treatment, and physical and/or mental burden may predispose to the development of malignant hypertension, and that these predisposing factors are likely to be associated with social class.

Reduced cardiac mass by nitrendipine is dissociated from systemic or regional haemodynamic changes in rats.

The effects of prolonged treatment (3 weeks) with nitrendipine (10 mg X kg-1 twice daily) on systemic and regional haemodynamics and cardiac mass were studied in SHR and WKY rats. Nitrendipine markedly decreased mean arterial pressure (26.0 +/- 0.4 vs 19.9 +/- 0.6 kPa, P less than 0.01) and total peripheral resistance (0.090 +/- 0.004 vs 0.066 +/- 0.004 U X kg-1, P less than 0.01) in SHR without significantly affecting cardiac output and heart rate, whereas in the WKY rats no significant systemic haemodynamic changes were noted. Increased splanchnic blood flow and a reduced splanchnic vascular resistance were found in the WKY rats; however, in the SHR rats, blood flows (ml X min-1 X g tissue-1) increased and organ vascular resistances (kPa X ml-1 X min-1 X 100 g tissue-1) decreased significantly (P less than 0.01) in the heart (5.25 +/- 0.28 vs 7.27 +/- 0.31 and 0.04 +/- 0.00 vs 0.02 +/- 0.00; P less than 0.01) and kidneys (6.53 +/- 0.4 vs 7.98 +/- 0.2 and 0.03 +/- 0.00 vs 0.02 +/- 0.00; P less than 0.01), respectively. Nevertheless, in both rat strains, absolute cardiac mass and left ventricular weight were reduced; but in the SHR rats, the relative weight of the heart and left ventricle to body weight was also reduced significantly (3.79 +/- 0.06 vs 3.31 +/- 0.09; P less than 0.01 and 2.85 +/- 0.06 vs 2.70 +/- 0.06; P less than 0.01, respectively). Thus, these studies show that nitrendipine, a slow-entry channel calcium blocker, regressed cardiac mass in rats through mechanisms that may be dissociated from their haemodynamic changes.

Short-term effects of angiotensin II blockade on renal blood flow and sympathetic activity in awake rats.

To investigate the effects of an angiotensin II type 1 receptor antagonist (CV-11974) on renal blood flow and renal sympathetic nerve activity compared with a calcium antagonist (nicardipine), we measured both parameters in conscious spontaneously hypertensive rats aged 13 to 15 weeks. One to 2 days after surgery, CV-11974 (n = 9) and nicardipine (n = 8) were intravenously administered to decrease arterial pressure in a similar time course and degree of hypotension. CV-11974 increased renal blood flow by 23 +/- 4% at the maximal fall in mean arterial pressure (-32 +/- 1 mm Hg), and renal nerve activity increased by 70 +/- 7%. The maximal increase in renal blood flow (+27 +/- 4%) was observed when mean pressure was reduced by approximately 20 mm Hg. The maximal reduction of renal vascular resistance (-33 +/- 3%) correlated significantly with pretreatment levels of plasma renin concentration (r = -.792). In contrast, nicardipine produced a progressive reduction of renal blood flow and marked increases in heart rate and renal nerve activity. Increases in heart rate and nerve activity were greater than those with CV-11974 treatment (P < .001). At the maximal fall in mean pressure (-32 +/- 1 mm Hg), renal blood flow decreased by 23 +/- 4%, which was significantly correlated with percent changes in renal nerve activity (+150 +/- 11%, r = -.744). Renal denervation in another set of rats (n = 6) improved renal blood flow and renal vascular resistance responses to nicardipine.(ABSTRACT TRUNCATED AT 250 WORDS)

Regression of left ventricular hypertrophy in two-kidney, one clip Goldblatt hypertension.

The effect of regression of left ventricular hypertrophy (LVH) on ventricular performance was studied in two-kidney, one clip Goldblatt hypertensive rats (2K1C) treated with methyldopa or by unclipping. Sham operations were performed in a total of 21 rats; 12 and nine were studied after 4 and 6 weeks, respectively. Hypertension was induced in 38 additional rats. Of these, 11 were studied at 4 weeks. Cardiac index was measured by electromagnetic flowmetry under light ether anesthesia, and ventricular performance was assessed by rapid intravenous saline infusion. Of the remaining 27 hypertensive rats at 4 weeks postclipping, 10 were treated with methyldopa (400 mg/kg/day) and nine were unclipped; eight were left untreated as controls. Two weeks thereafter, ventricular performance was determined as described above. When expressed as the relationship between cardiac index and LV end-diastolic pressure, ventricular performance tended to be depressed in 2K1C. Ventricular performance, mean arterial pressure, and LV-to-body weight ratio returned to control in unclipped rats. Whereas methyldopa resulted in regressed LVH, its effect on mean arterial pressure and total peripheral resistance was not as marked as unclipping, both remaining significantly increased (p less than 0.001). The disparate effects of unclipping and methyldopa on systemic hemodynamics indicate that the improved ventricular performance with methyldopa was related more to its effect on LVH, suggesting that in these animals regression of LVH was associated with improved ventricular performance.

DOCA-salt induced malignant hypertension in spontaneously hypertensive rats.

DOCA-salt hypertension was produced in 10 male 10-week-old normotensive Wistar-Kyoto (WKY) rats receiving deoxycorticosterone acetate (DOCA; 100 mg/kg, subcutaneous pellet) and 1% NaCl drinking water and was compared with data from 10 age- and sex-matched WKY receiving normal tap water (C). These data were also compared with spontaneously hypertensive (SHR) rats similarly treated. After 10 weeks on these programmes, systemic and regional haemodynamics were determined in conscious rats using microsphere techniques. DOCA-salt treatment increased mean arterial pressure (MAP), total peripheral resistance index (TPRI), cardiac and renal weights in both WKY and SHR. In contrast to SHR (C), the SHR (DOCA) demonstrated more severe MAP elevation (204 +/- 4 versus 185 +/- mmHg; P less than 0.01), more severe systemic and regional (especially renal) vasoconstriction, and malignant vasculitis associated with azotaemia and hyperuricaemia. The hyperuricaemia was related inversely to renal blood flow (r = -0.74; P less than 0.01) and directly to renal vasoconstriction (r = 0.65; P less than 0.05) in SHR (DOCA). These data suggest that in both WKY and SHR, DOCA and salt produced marked cardiovascular changes and SHR rats developed malignant hypertension.

Brain angiotensin II contributes to the development of hypertension in Dahl-Iwai salt-sensitive rats.

OBJECTIVE: To examine the role of brain angiotensin II in the development of salt-induced hypertension in Dahl-Iwai salt-sensitive (DIS) rats. METHODS: Male DIS and Dahl-Iwai salt-resistant (DIR) rats aged 5 or 6 weeks were implanted with an intracerebroventricular cannula, and either chronic intracerebroventricular infusion of 5 micrograms/day CV-11974, a non-peptide type-1 angiotensin II receptor antagonist or artificial cerebrospinal fluid (aCSF) was started. The rats were fed a diet containing 8% sodium chloride. RESULTS: On day 11 or 12 of chronic infusion, DIS rats given CV-11974 intracerebroventricularly exhibited a significantly lower mean arterial pressure than DIS rats given aCSF intracerebroventricularly or intravenous infusion of CV-11974. In DIR rats, intracerebroventricular infusion of CV-11974 did not alter the mean arterial pressure. Sodium and water balances were similar in all of the groups. Plasma vasopressin and noradrenaline levels did not differ among the groups, although the plasma renin concentration was significantly lower in DIS rats given aCSF intracerebroventricularly. Arterial baroreflex control of heart rate and pressor response to intravenous injection of phenylephrine were not altered in rats given CV-11974 intracerebroventricularly. CONCLUSION: The integrity of the brain renin-angiotensin system is necessary for the development of salt-induced hypertension in DIS rats.

Multiple risk factor clustering of hypertension in a screened cohort.

OBJECTIVE: A family history of hypertension, obesity, diabetes mellitus, hypercholesterolaemia and hypertriglyceridaemia have all been associated with the risk for hypertension. We evaluated whether the clustering of these risk factors increases the risk for hypertension or whether the accumulation of risk factors is associated with the blood pressure level in non-hypertensive subjects. METHODS AND SUBJECTS: We assessed the clinical data and family history of hypertension (in parents and siblings) for 9914 individuals (6163 men and 3751 women, 18-89 years old) who were screened in Okinawa, Japan, in 1997. RESULTS: In 9914 subjects (2465 hypertensive and 7449 non-hypertensive subjects), all the five factors were positively associated with hypertension. The odds ratios (95% confidence interval) for the number of risk factors were 1.88 (1.62-2.18) for one risk factor, 3.06 (2.62-3.57) for two, 5.25 (4.37-6.30) for three, 8.71 (6.48-11.72) for four and 24.48 (8.49-70.56) for five, after adjusting for age, sex, alcohol consumption, cigarette smoking and physical exercise habits. In non-hypertensive subjects, multivariate regression analyses showed that the number of risks was positively correlated with blood pressure; the regression coefficient was 1.96 (P < 0.0001) for systolic blood pressure, and 1.47 (P < 0.0001) for diastolic blood pressure after adjusting for age and sex. CONCLUSIONS: Clustering of risk factors was significantly associated with hypertension. The number of risk factors positively correlated with the blood pressure levels in nonhypertensive subjects. The accumulation of risk factors may play an important role in the pathogenesis of hypertension, and thus the aggregation of risk factors may need to be addressed in primary prevention efforts related to hypertension.

Cardiovascular and sympathetic effects of L-glutamate and glycine injected into the rostral ventrolateral medulla of conscious rats.

The aim of the present study was to examine the effects of L-glutamate and glycine microinjected into the rostral ventrolateral medulla (RVLM) in conscious unrestrained rats. Microinjection of 2 nmol of L-glutamate increased the mean arterial pressure (MAP) and renal sympathetic nerve activity (RSNA) in the conscious rats. The RSNA responses were significantly larger in the conscious rats than in anesthetized rats, while the magnitude of the pressor responses was similar in conscious and urethane-anesthetized rats. L-Glutamate injection significantly decreased heart rate in the conscious rats, whereas it increased the heart rate slightly but not significantly in the anesthetized rats. Microinjection of 100 nmol of glycine into the RVLM of conscious rat decreased MAP and RSNA. In 2 of the 6 rats examined, the depressor and sympathoinhibitory responses were preceded by a few seconds of a pressor and sympathoexcitatory phase. The decreases of RSNA in response to glycine injection were significantly larger in the conscious rats than in the anesthetized rats, whereas the magnitude of the depressor responses was similar in the two groups of rats. Heart rate decreased in response to glycine injection into the RVLM in the conscious and the anesthetized rats. In conclusion, in conscious unrestrained rats, as well as in urethane-anesthetized rats, L-glutamate acts as a sympathoexcitatory agent and glycine acts as a sympathoinhibitory agent in the RVLM. The sympathetic responses to these amino acids are larger in conscious rats than in anesthetized rats.

Family history of hypertension and blood pressure in a screened cohort.

We sought to determine whether a family history of hypertension is quantitatively associated with the prevalence of hypertension and blood pressure in a screened cohort. Clinical data and family (parents and siblings) histories regarding hypertension were collected from 9,914 individuals (probands) who were interviewed and examined during a one-day clinic by the Okinawa General Health Maintenance Association in 1997. We used logistic analysis to calculate odds ratios with adjustments for age, sex, body mass index, total cholesterol, presence of diabetes mellitus, alcohol use, cigarette smoking, and status of physical exercise. The age- and sex-adjusted hypertension prevalences in probands were 29.0% for those with 1 family member with a history of hypertension (n=2,112), 37.6% for those with 2 hypertensive family members (n=374), and 47.3% for those with 3 or more hypertensive family members (n=68). In contrast, only 16.4% of probands who reported no family history of hypertension (n=7,360) were hypertensive themselves. The trend of the prevalence according to the number of family members with a history of hypertension was significantly positive (p=0.003). The adjusted odds ratios (95% confidence interval) of hypertension were 2.74 (2.43-3.10) for 1 member, 4.62 (3.62-5.90) for 2 members, and 6.04 (3.51-10.4) for 3 or more members with a history of hypertension. In patients without antihypertensive medication (n=9,009), systolic/diastolic blood pressure (mean +/- SD) was 121 +/- 17/75 +/- 11 for 1 member, 124 +/- 18/77 +/- 12 for 2 members, and 127 +/- 17/78 +/- 11 for 3 or more members with a history of hypertension. In contrast, the mean systolic/diastolic blood pressure of probands who reported no family history of hypertension (n=7,360) was 119 +/- 15/74 +/- 10 mmHg, which was significantly (p<0.05) lower than that of any of the groups with hypertensive family members. In conclusion, an increase in the number of family members with hypertension was associated with an increasing prevalence of hypertension and blood pressure in the probands, independent of conventional risk factors for hypertension. Family members of hypertensive subjects may need to be treated in primary prevention efforts related to hypertension.

Developmental changes in expression of angiotensinogen mRNA in rat nephron segments.

We studied the localization of angiotensinogen mRNA in rat nephron segments and the differences in angiotensinogen mRNA levels between male Sprague-Dawley rats at 6 and 12 wk of age using reverse transcription and polymerase chain reaction (RT-PCR). Each nephron segment of the rat kidney was microdissected. Total RNA was prepared and used in the following RT-PCR assay. The PCR products were size-fractionated by agarose gel electrophoresis, visualized with ethidium bromide staining, and identified by Southern blot analysis. The relative amounts of products were determined by densitometry. Strong bands corresponding to angiotensinogen mRNA were detected from proximal convoluted and straight tubules, and weaker bands were found in glomeruli. The signals in all tissues in 12-wk-old rats were weaker than those in 6-wk-old rats. Since local angiotensinogen is the unique substrate of the tissue renin-angiotensin system and exerts an autocrine-paracrine influence on renal function, the changes in tubular angiotensinogen may be related to physiological and morphological changes in the rat kidney during development.

Modulation of baroreflex function by angiotensin II endogenous to the caudal ventrolateral medulla.

Neurons in the ventrolateral medulla (VLM) mainly determine the tonic sympathetic activity. The caudal VLM (CVLM) relays baroreflex signals to the rostral VLM. We have reported that endogenous angiotensin II (ANG II) contributes to the ongoing activity of the VLM neurons. In the present study, we examined if ANG II endogenous to the CVLM modulates the baroreflex function in anesthetized normotensive Sprague-Dawley rats. Changes in renal sympathetic nerve activity (RSNA) in response to changes in mean arterial pressure (MAP) induced by i.v. infusion of phenylephrine and nitroglycerin were recorded before and after bilateral microinjection of [Sar1, Thr8]-ANG II, an ANG II antagonist, into the CVLM. The ANG II antagonist injection into the CVLM significantly increased MAP and RSNA by 17.6 +/- 8.0 mmHg (mean +/- S.D.) and 36.3 +/- 18.1%, respectively. It also significantly increased the baroreflex sensitivity (BS) from -0.49 +/- 0.38 to -0.74 +/- 0.37%/mmHg during nitroglycerin infusion. In contrast, the BS examined by phenylephrine infusion was not altered by the pretreatment with ANG II antagonist. Injection of artificial CSF affected neither the baseline values of MAP and RSNA nor the BS. These results suggest that ANG II endogenous to the CVLM exert a modulating role in baroreflex control of RSNA.

A case of syndrome of inappropriate secretion of antidiuretic hormone (SIADH) with low plasma concentrations of antidiuretic hormone.

A 66-year-old Japanese man presented with persistent hyponatremia without polydipsia and polyuria. Laboratory examination showed serum sodium of 117 mEq/l, plasma osmolality 239 mosm/kg, urine sodium 108 mEq/l, urine osmolality 577 mosm/kg, and normal levels (less than 2.0 pg/ml) of serum antidiuretic hormone (ADH). ADH release was regulated normally with changes in plasma osmolality. No obvious cause for the syndrome of inappropriate secretion of ADH (SIADH) could be detected. However, 20 months later, the patient had bouts of hematuria and was found to have cancer of the urinary bladder. Increased renal sensitivity to ADH was suspected as the underlying mechanism of SIADH.

[A female case of Fournier's gangrene in a patient with lupus nephritis].

Infection is one of the common causes of death in patients with systemic lupus erythematosus (SLE). It is associated with the use of immunosuppressive agents, renal failure, and increased disease activity. Fournier's gangrene is a necrotizing fasciitis occurring in the genital region. It is rare, but can be crucial if surgical drainage is delayed. We report a female case of Fournier's gangrene occurring in a patient with lupus nephritis and chronic renal failure. The patient was a 21-year-old female with chronic renal failure due to lupus nephritis. She had suffered from watery diarrhea one month before admission. It improved after increasing the dose of prednisolone, but, she was complicated with Bartholin abscess. The vaginal pain rapidly spread to the left lower quadrant abdomen despite treatment with oral cephalosporin. Focal incision was performed and black fluid emerged with a foul smell. Pelvic computed tomography (CT) revealed many bubbles in that region. She was found to have septic shock on transfer to our hospital. Thereafter, emergency debridement was performed, followed by antibiotic therapy and hyperbaric oxygen therapy. Organisms were found to be 5 anerobes, such as Bacteroides species, and 3 aerobics, such as Morganella morganii. Fournier's gangrene was improved via these treatments, but she needed maintenance hemodialysis. Fournier's gangrene complication should be considered in SLE with urogenital infection.