ISSN:0263-6352    

出版商:OVID    

年代:1983

数据来源: OVID

ISSN:0263-6352    

出版商:OVID    

年代:1983

数据来源: OVID

ISSN:0263-6352    

出版商:OVID    

年代:1983

数据来源: OVID

摘要:

Possible adrenal and autonomie mechanisms contributing to the onset of essential hypertension were studied in 18 men selected from the upper and lower extremes of blood pressure distribution within a larger population. In eight of the nine pairs of subjects, who were matched for age and obesity, those with higher pressure had significantly higher resting levels of both free adrenaline and noradrenaline sulphate in plasma than their lower pressure counterparts. The higher pressure group showed a positive correlation between diastolic blood pressure and bothfree and total noradrenaline levels (r = 0.77, P < 0.05, and r = 0.81, P < 0.01, respectively). In those with lower pressure, systolic blood pressure correlated closely with plasma adrenaline (r = 0.92, P < 0.001). Increased adrenal medullary activity and altered autonomie tone appear to be features of the higher range of normal blood pressure and may precede the onset of essential hypertension.

ISSN:0263-6352    

出版商:OVID    

年代:1983

数据来源: OVID

摘要:

These studies examine the effect of sodium (Na) and potassium (K) intake on the pressor and metabolic actions of ACTH (20 μg/kg/day) in sheep. After 21 days on each of five regimens in which Na and K intake varied from 0 to 100 mmol/day, no simple relationship between Na and K intake and blood pressure was found. After five days of ACTH treatment, mean arterial pressure (MAP) rose + 5 mmHg in sheep on 0 mmol Na, 0 mmol K (expressed as 0Na0K); + 13 mmHg on 10Na700K; + 5 mmHg on 0Na700K; + 20 mmHg on 700Na0Kand + 24 mmHg on 700Na700K.Plasma [K] was unchanged by ACTH on 0Na0Kbut fell in sheep on the other electrolyte regimens. Water intake increased with ACTH on all regimens except 700Na0K. Blood aldosterone concentration was high in sheep maintained on 0Naregimens but lower after five days of ACTH treatment in all groups. Blood cortisol and corticosterone concentrations increased with ACTH on all regimens studied.

ISSN:0263-6352    

出版商:OVID    

年代:1983

数据来源: OVID

摘要:

Conscious male beagle dogs were given constant intravenous infusions of noradrenaline for 14 days, four receiving 125 ng/kg/min and four 250 ng/kg/min. Before, during and after these infusions dose-response studies were done in which additional noradrenaline was infused at 500, 1000 and 2000 ng/kg/min, each rate for 1 h. Blood samples were taken before and during infusions for measurement of haematocrit and plasma concentrations of noradrenaline, active renin, angiotensin II, aldosterone, sodium and potassium. Fourteen-day infusion of noradrenaline at 125 ng/kg/min did not raise blood pressure significantly though infusion at 250 ng/kg/min did, but for the first week of infusion only. Heart rate decreased significantly at both rates. Arterial pressure fell markedly and significantly on stopping infusion. Mean plasma concentrations of renin, angiotensin II and aldosterone tended to be lower during prolonged infusion of noradrenaline, but only the fall of renin during the second week was significant in one group of dogs. Noradrenaline at higher rates significantly raised blood pressure and increased plasma concentrations of renin and angiotensin II. Plasma aldosterone concentration did not rise significantly, perhaps because plasma potassium concentration decreased; in support of this theory changes of plasma aldosterone correlated with changes of plasma potassium but not with changes of angiotensin II. The rise in arterial pressure during dose-response studies was related to the increase of plasma noradrenaline. Prolonged infusion of noradrenaline did not alter the dose-response relation between plasma noradrenaline concentration and arterial pressure.

ISSN:0263-6352    

出版商:OVID    

年代:1983

数据来源: OVID

摘要:

The role of arginine vasopressin (AVP) in malignant renal hypertension was investigated using the homozygous Brattleboro (vasopressin-deficient) rat. Brattleboro rats with complete aortic-ligature between the renal arteries developed malignant hypertension with the same frequency and severity as normal Long-Evans rats subjected to the same procedure. The Long-Evan's hypertensive rats had significantly elevated plasma AVP levels. Plasma renin activity and plasma angiotensin II levels were significantly elevated in both Brattleboro and Long-Evans rats with malignant hypertension and the levels reached were equivalent in both groups. Thus, the renin-angiotensin system did not compensate for the lack of AVP in malignant hypertensive Brattleboro rats. Specific vascular lesions of fibrinoid necrosis were observed in a high percentage of rats with malignant hypertension, in both the Brattleboro and Long-Evans strains. We conclude that AVP does not play a primary role in the pathogenesis of malignant renal hypertension and, in particular, in the development of the vascular lesions of fibrinoid necrosis.

ISSN:0263-6352    

出版商:OVID    

年代:1983

数据来源: OVID

摘要:

Seven young patients with newly diagnosed severe hypertension were studied for one week. The mean age was 34.9 years (range 28–44). The mean initial values ± s.d. for systolic and diastolic pressures were 223 ± 27 and 141 ± 8 mmHg, respectively. Secondary hypertension was excluded by conventional methods and serum creatinine was normal.A pronounced but quite variably elevated albumin excretion 440 ± 448 μg/min (mean ± s.d.) and a moderately increased β2-microglobulin excretion 3.06 ± 3.29 μg/min was noted before treatment. The abnormal albumin excretion with ensuing fall in blood pressure was rapidly and almost completely reversible in all but one patient during conventional treatment and the increased β2-microglobulin excretion was totally reversible in all but one patient. Both albumin and β2-microglobulin excretion rate were positively correlated to arterial pressures in all patients. Thus glomerular and to some extent tubular protein handling were both affected in untreated patients, but rapidly reversible during initial antihypertensive treatment.The data indicate that the β2-microglobulin hyperexcretion is secondary to enhanced filtration of plasma protein saturating the tubular reabsorption capacity, while the hyperexcretion of albumin is mainly due to the increased filtration pressureper se, though other factors may be partly responsible.

ISSN:0263-6352    

出版商:OVID    

年代:1983

数据来源: OVID

摘要:

The activity of renal Na-K-ATPase was compared in hypertension-prone (SBH) and hypertension-resistant (SBN) Sabra rats on regular sodium intake and 2–3 weeks after a high sodium diet. ATPase activity was determined in single nephron segments by a micromethod. The activity profile was found to be similar in the two substrains on both regimens. Following high sodium intake there was a significant increment of Na-K-ATPase activity which was limited to the medullary thick ascending limb in the two substrains. The results clearly indicate a lack of relationship between renal Na-K-ATPase activity and proneness or resistance to hypertension in this experimental model.

ISSN:0263-6352    

出版商:OVID    

年代:1983

数据来源: OVID

摘要:

The development of hypertension in two-kidney, one clip renal hypertensive rats (2K, 1C RHR) was not altered by treatment with DOCA and saline solution as drinking fluid for two months of observation. However, the administration of DOCA and salt suppressed plasma renin activity (PRA), the renal renin content (RRC) of the clipped kidney and the response to a single oral dose of captopril (10 mg/kg). The weight of the contralateral kidney was increased by the administration of DOCA-salt, while that of the ischaemic kidney was not changed.The withdrawal of DOCA-salt treatment restored the PRA and the effects of captopril to a similar degree to the non-treated group. The acute hypotensive effects of captopril were reduced on the 10th week compared with the 7th week after renal arterial constriction in 2K, 1C RHR. The fall in blood pressure induced by captopril significantly correlated with the initial PRA both in the 7th and 10th week after clipping. There was a significant correlation between PRA and RRC of the clipped kidney.Rats previously treated with DOC-salt had either removal of the contralateral kidney with removal of the clip from the ischaemic kidney, or removal of the ischaemic kidney. Blood pressure fell to normal levels in the undipped group and in the nephrectomy group, but the fall in the latter group was transient and within two weeks had risen to significantly higher levels than in the undipped group.It is concluded that structural vascular change following DOC-salt hypertension is insufficient to cause persisting hypertension except when it occurs in the renal circulation.

ISSN:0263-6352    

出版商:OVID    

年代:1983

数据来源: OVID