Vascular function and nitric oxide production in chronic social-stress-exposed rats with various family history of hypertension

• Published in: Journal of physiology and pharmacology : an official journal of the Polish Physiological Society Vol. 58; no. 3; p. 487
• Main Authors: Bernatova, I, Csizmadiova, Z, Kopincova, J, Puzserova, A
• Format: Journal Article
• Language: English
• Published: Poland 01-09-2007
• Subjects: Acetylcholine - pharmacology; Animals; Aorta, Thoracic - drug effects; Aorta, Thoracic - metabolism; Body Weight - physiology; Crowding - physiopathology; Crowding - psychology; Dose-Response Relationship, Drug; Female; Femoral Artery - drug effects; Femoral Artery - physiopathology; Heart Rate - physiology; Hypertension - genetics; Hypertension - physiopathology; Hypothalamus - drug effects; Hypothalamus - metabolism; In Vitro Techniques; Male; NG-Nitroarginine Methyl Ester - pharmacology; Nitric Oxide - metabolism; Nitric Oxide Synthase - antagonists & inhibitors; Nitric Oxide Synthase - metabolism; Norepinephrine - pharmacology; Rats; Rats, Inbred SHR; Rats, Wistar; Serotonin - pharmacology; Social Behavior; Species Specificity; Stress, Psychological - physiopathology; Vasodilation - drug effects
• ISSN: 1899-1505

The study investigated the effect of chronic crowding stress on vascular function and nitric oxide (NO) production in rats with various family history of hypertension. Wistar (W), wBHR (offspring of W dams and spontaneously hypertensive sires), sBHR (offspring of spontaneously hypertensive dams and W sires) and spontaneously hypertensive rats (SHR) were used. Twelve-week-old males were divided into the control or crowded group for eight weeks. Basal blood pressure (BP, determined by tail-cuff plethysmography) of W, wBHR, sBHR and SHR rats was 112 +/- 3, 129 +/- 2, 135 +/- 2 and 187 +/- 3 mmHg, respectively. Crowding increased BP and reduced aortic NO synthase activity only in sBHR and SHR rats, without alterations in hypothalamic NO production. Acetylcholine-induced vasorelaxation of the femoral artery of stress-exposed rats was improved in W, unaltered in wBHR and sBHR and reduced in SHR. Crowding reduced serotonin-induced vasoconstriction in W and wBHR rats but had no effect in sBHR and SHR rats. In conclusion, the results suggest that crowded offspring of normotensive mothers were able to modify their vascular function in order to maintain BP at normal levels. On the other hand, offspring of hypertensive mothers were unable of effective adaptation of vascular function in stressful conditions resulting in gradual development of hypertension.