摘要:

This study was undertaken to evaluate the associations of body fat and its distribution with casual and ambulatory blood pressure in nonobese men. One hundred and thirty-five normotensive or mildly hypertensive (but untreated) men employed at three work sites were studied. Casual blood pressure was measured at the work site at initial screening and on a second occasion by a nurse. Ambulatory blood pressure was measured noninvasively for 24 hours on a workday and analyzed as work, home, and sleep blood pressure measurements. Anthropometric measurements included height, weight, and waist and hip circumferences. Blood pressure was highest while at work; home blood pressure was higher than screening blood pressure or nurse blood pressure, and sleep blood pressure was lowest. Weight and both waist and hip circumferences (but not their ratio) were all significantly correlated with screening, nurse, and sleep blood pressures but not with work or home blood pressures. Stepwise regression analysis showed that waist circumference was the best overall predictor of blood pressure. We suggest that in situations where blood pressure is the dependent variable, correlations with other variables may be closest for “basal” measures of blood pressure and may be obscured by the effects of daily activities on blood pressure.

ISSN:0194-911X    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

Spontaneously hypertensive rats have reduced peripheral insulin sensitivity. To determine whether hypertensive rats demonstrate reduced response to the antinatriuretic effect of insulin, urinary sodium excretion was determined in hypertensive and normotensive rats (n=7 per group) before and during euglycemic insulin administration at two infusion rates (21 milliunits/kg load and 4 milliunits/kg/min or 85 milliunits/kg load and 8 milliunits/kg/min). Hypertensive and normotensive time controls received the vehicle for insulin administration. Mean arterial pressure was greater (/?<0.05) and inulin clearance was less (/?<0.05) in hypertensive than normotensive rats before insulin infusion. Baseline fractional sodium excretion was not different between groups. Low dose insulin infusion reduced (p<0.05) fractional sodium excretion from 0.81±0.43% to 0.31±0.07% in hypertensive rats and from 1.05±0.37% to 0.47±0.18% in normotensive rats. High dose insulin infusion reduced (/><0.05) fractional sodium excretion from 0.67±0.22% to 0.21±0.08% in hypertensive rats and from 0.81±0.15% to 0.30±0.09% in normotensive rats. Sodium excretion was unchanged in time controls. The reduction in sodium excretion was similar in both rat groups during low dose and high dose insulin infusions. Mean arterial pressure and inulin clearance were unchanged from baseline values during insulin infusion in all rat groups. Glucose requirement to maintain euglycemia was greater (p<0.05) in normotensive than hypertensive rats at both insulin infusion rates. Thus, while hypertensive rats have reduced sensitivity to the hypoglycemic effects of insulin, the antinatriuretic response to insulin is not different from that of normotensive rats. Furthermore, the presence of hypertension does not modulate the antinatriuretic activity of insulin.

ISSN:0194-911X    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

Although hyperinsulinemia and increased adrenergic activity have been postulated to be important factors in obesity-associated hypertension, a cause and effect relation between insulin, catecholamines, and hypertension has not been established. The aim of this study was to determine whether chronic hyperinsulinemia, comparable with that found in obese hypertensive patients, causes hypertension in normal dogs, increases plasma catecholamines, or potentiates the blood pressure effects of norepinephrine. In six normal dogs, insulin infusion (1.0 milliunits/ kg/min) for 7 days, with euglycemia maintained, increased fasting insulin fourfold to sixfold. However, mean arterial pressure did not increase, averaging 99±2 mm Hg during the control period and 91±3 mm Hg during the 7 days of insulin infusion. Insulin did not alter plasma norepinephrine or epinephrine, which averaged 171±27 and 71±14 pg/ml, respectively, during the control period and 188±29 and 45±12 pg/ml during the 7 days of insulin infusion. In six dogs, norepinephrine was infused (0.2 μg/kg/min) for 7 days to raise plasma norepinephrine to 2,940±103 pg/ml. Insulin infusion (1.0 milliunits/kg/min) for 7 days during simultaneous infusion of norepinephrine did not further increase mean arterial pressure, which averaged 101±3 during norepinephrine and 98±2 mm Hg during insulin plus norepinephrine infusion. Thus, chronic hyperinsulinemia did not increase mean arterial pressure or plasma catecholamines and did not potentiate the blood pressure actions of norepinephrine. These observations provide no evidence that chronic hyperinsulinemia or interactions between insulin and plasma catecholamines cause hypertension in normal dogs.

ISSN:0194-911X    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

Two subclasses of cyclic guanosine monophosphate (GMP) -specific phosphodiesterases were identified in vascular tissue from several beds. The activity of one subclass (phosphodiesterase IB) was stimulated severalfold by calmodulin and selectively inhibited by the phosphodiesterase inhibitor TCV-3B. The activity of the other subclass (phosphodiesterase IC) was not stimulated by calmodulin and was selectively inhibited by the phosphodiesterase inhibitor M&B 22,948. To assess the involvement of both subclasses in regulating cyclic GMP-dependent responses, the ability of TCV-3B and M&B 22,948 to potentiate the in vitro and in vivo responses to the endogenous guanylate cyclase stimulator atrial natriuretic factor (ANF) was evaluated. Both TCV-3B and M&B 22,948 relaxed isolated rabbit aortic and pulmonary artery rings and also potentiated the relaxant effect of ANF. In addition, both inhibitors produced small increases in urine flow and sodium excretion in anesthetized rats and potentiated the diuretic and natriuretic responses to exogenous ANF. M&B 22,948 (30 μ/kg/min) produced a threefold increase in the natriuretic response to simultaneously administered ANF, and TCV-3B (10 μ/kg/min) produced a twofold increase in the response to ANF. The results of the present experiments suggest that both the calmodulin-sensitive and calmodulin-insensitive subclasses of cyclic GMP-specific phosphodiesterase play a role in regulating the in vitro and in vivo response to ANF.

ISSN:0194-911X    

出版商:OVID    

年代:1990

数据来源: OVID

ISSN:0194-911X    

出版商:OVID    

年代:1990

数据来源: OVID

ISSN:0194-911X    

出版商:OVID    

年代:1990

数据来源: OVID

ISSN:0194-911X    

出版商:OVID    

年代:1990

数据来源: OVID

ISSN:0194-911X    

出版商:OVID    

年代:1990

数据来源: OVID