Hyperinsulinemic rats are normotensive but sensitized to angiotensin II.

• The effect of insulin on blood pressure (BP) is debated, and an involvement of an activated renin-angiotensin aldosterone system (RAAS) has been suggested. We studied the effect of chronic insulin infusion on telemetry BP and assessed sympathetic activity and dependence of the RAAS. Female Sprague-Dawley rats received insulin (2 units/day, INS group, n = 12) or insulin combined with losartan (30 mg.kg(-1).day(-1), INS+LOS group, n = 10), the angiotensin II receptor antagonist, for 6 wk. Losartan-treated (LOS group, n = 10) and untreated rats served as controls (n = 11). We used telemetry to measure BP and heart rate (HR), and acute ganglion blockade and air-jet stress to investigate possible control of BP by the sympathetic nervous system. In addition, we used myograph technique to study vascular function ex vivo. The INS and INS+LOS groups developed euglycemic hyperinsulinemia. Insulin did not affect BP but increased HR (27 beats/min on average). Ganglion blockade reduced mean arterial pressure (MAP) similarly in all groups. Air-jet stress did not increase sympathetic reactivity but rather revealed possible blunting of the stress response in hyperinsulinemia. Chronic losartan markedly reduced 24-h-MAP in the INS+LOS group (-38 +/- 1 mmHg P < 0.001) compared with the LOS group (-18 +/- 1 mmHg, P

Ämnesord

MEDICIN OCH HÄLSOVETENSKAP  -- Medicinska och farmaceutiska grundvetenskaper -- Fysiologi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Basic Medicine -- Physiology (hsv//eng)

Nyckelord

Acetylcholine

pharmacology

Angiotensin II

metabolism

Angiotensin II Type 1 Receptor Blockers

pharmacology

Animals

Antihypertensive Agents

pharmacology

therapeutic use

Aorta

physiopathology

Blood Glucose

metabolism

Blood Pressure

drug effects

Blood Pressure Monitoring

Ambulatory

methods

Disease Models

Animal

Female

Ganglia

Sympathetic

drug effects

physiopathology

Ganglionic Blockers

pharmacology

Glucose

administration & dosage

Heart Rate

drug effects

Hexamethonium

pharmacology

Hyperinsulinism

chemically induced

complications

drug therapy

metabolism

physiopathology

Hypertension

drug therapy

etiology

metabolism

physiopathology

Insulin

administration & dosage

Insulin Infusion Systems

Losartan

pharmacology

therapeutic use

Myography

Rats

Rats

Sprague-Dawley

Renin

blood

Renin-Angiotensin System

drug effects

genetics

Telemetry

Time Factors

Vasodilation

Vasodilator Agents

pharmacology

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)