摘要:

Ablation of tissue surrounding the anteroventral third cerebral ventricle (AV3V) has been demonstrated to prerent and reverse renal hypertension in the rat. The contribution of this brain area to the maintenance of hypertension in other species has not been examined. In toe present investigation, an attempt was made to produce twohyphenkidney, one dip renal hypertension in rabbits with histologicaily and functionally defined AV3V destruction. Electrolytic lesion of the AV3V in rabbits produced effects closely resembling those previously seen in rats: Increased plasma volume and plasma sodium, temporary adipsia, no change in resting arterial pressure or heart rate, and significant attenuation of pressor responsiveness to angiotensin II (AH) delivered intracranially. However, the increase In arterial pressure observed over a 4-week period following the application of a 0.5 mm silver dip to the left renal artery (opposite kidney intact) was identical in 12 AV3V lesioned and 12 shamhyphenoperated rabbits. Hypertension development was not accompanied by significant sodium retention, water retention, or plasma/extracellular fluid volume expansion in either group of rabbits. Pressor responses to intravenous infusions of AH and norepinephrine were identical in sham and AV3V HYPHENX rabbits. Thus, destruction of the AV3V, and the attendant reduction in the central pressor action of All, does not alter the pattern of development of twohyphenkidney, one clip renal hypertension in the rabbit. The contrasting results in rats and rabbits could be explained by the differing contribution of the area postrema to the pressor action of AH in the two species. (Hypertension 4: 155–160, 1982)

ISSN:0194-911X    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

Experiments were performed to evaluate the effect of dehydration on neurohypophyseal hormone secretion, both vasopressin and oxytocin, fluid balance, and blood pressure in male spontaneously hypertensive rats (SHR) and their normotenslve controls, Wistar Kyoto (WKY). Metabolic studies showed that the antidiuretic response to dehydration (24 and 48 hours of water deprivation) was significantly depressed (p< 0.01) in the hypertensive animals. They responded inappropriately to dehydration with a greater loss of water and sodium and a larger increase in hematocrit. In contrast, the vasopressin response (both urinary excretion and plasma levels) was increased. The peak plasma levels were 25.3 pg/ml (SHR) compared to 16.6 pg/ml (WKY), while the urinary excretion was 22.5 ng/24 hrs (SHR) vs 9.0 ng/24 hrs (WKY). Dehydration also elicited a stimulation of oxytocin secretion, with no differences observed in the responses of the groups. Blood pressure was significantly greater in the SHR and It did not change during dehydration. These results provide further support for the idea that hypertension is associated with abnormalities in the control of fluid/electrolyte balance. (Hypertension 4: 161–166, 1982)

ISSN:0194-911X    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

The phannacoklnetic disposition and antihypertensive response of bolus infusions of diazoxide, 1, 2, or 4 mg/kg over 5,10, or 20 seconds, were examined in seven patients with chronic stable essential hypertension and mean arterial pressures (MAP) between 122 and 155 mm Hg off therapy. Maximal reductions in MAP were noted 2 minutes after each dose, and a linear correlation was obtained in all patients between dose or plasma diazoxide concentration and maximal change in MAP. Individual concentrationhyphentime curves were analyzed to determine the apparent volume of distribution at steady state (Vd$$, range, 0.178 to 0.250 liter/kg), beta t 1/2 (range, 32 to 62.5 hours), and plasma clearance rate (Clprange, 2.2 to 5.3 ml/kg*hour−1) for the calculation of loading and maintenance doses designed to produce steadyhyphenstate concentrations within 0.5 hours. These infusions resulted in steadyhyphenstate reductions in MAP (16% to 30%) which could be predicted from the concentrationhyphenresponse curves of each patient after bolus infusions. With the use of kinetic principles, a diazoxide dose regimen (average load, 7.5 mg/kg at 7.5 mg/min; average maintenance, 10% of loading dose every 6 hours) produced gradual and predictable reductions In MAP in patients with accelerated hypertension, since the response was proportional to plasma diazoxide concentrations. (Hypertension 4: 167–173, 1982)

ISSN:0194-911X    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

Publishing a scientific journal demands much from its constituency, particularly the critical peer review on which excellence is based. The Editors of Hypertension wish to express thanks to the Editorial Board for its support and guidance. Also, we particularly wish to acknowledge the many reviewers who are not members of the Editorial Board who have given willingly of their time and effort. Their names appear on the following pages.

ISSN:0194-911X    

出版商:OVID    

年代:1982

数据来源: OVID