We examined changes in the plasma levels of estradiol (E2), insulin-like growth factor-1 (IGF-1), ACTH, cortisol and catecholamines accompanying various kinds of hypothalamically elicited emotional behaviors in female cats. The emotional behaviors consisting of restlessness, threat and searching-biting (S-B) were elicited intermittently for 6 h by electrical stimulation of the anterior hypothalamus (AH), ventromedial hypothalamus (VMH) and lateral hypothalamus (LH), respectively, in awake and free-moving conditions. The blood was sampled three times immediately before, 1 h after and 6 h after the start of stimulation. The plasma levels of ACTH, cortisol and catecholamines significantly increased in both restlessness and threat behaviors, whereas in the S-B behavior, the ACTH level significantly increased, while the cortisol level showed a slight nonsignificant increase. No changes were observed in the plasma catecholamine levels in the S-B behavior. The plasma E2 level significantly increased in threat behavior after 1 and 6 h of stimulation compared to the prestimulation levels, and the level also increased in comparison to the control group after 1 h. In contrast, the restlessness and S-B behaviors had little or no effect on the E2 level. No significant changes were observed in the plasma levels of IGF-1 in all behavior groups. These findings suggest that various hypothalamically elicited emotional behaviors have differential effects on the plasma E2, but not on the IGF-1 levels. Therefore, E2 and IGF-1 are regulated independently of each other.

Adrenocorticotropic Hormone↗

PubMedDate not supplied

Angiotensin II receptors in cardiac left ventricles of Dahl rats.

1. Dahl Iwai salt-sensitive (DS) rats have been reported as becoming hypertensive with left ventricular hypertrophy (LVH) and heart failure when on a high-salt diet. Their circulating renin-angiotensin system (RAS) has been reported to be suppressed. To evaluate the role of angiotensin II (AngII) type 1 and type 2 receptors (AT1 and AT2, respectively) in LVH, we compared cardiac AT1 and AT2 receptors in 10-week-old DS rats and Dahl Iwai salt-resistant (DR) rats. 2. Seven pairs of 6-week-old male DS and DR rats were fed either a low- or high-salt diet (0.3 or 8% NaCl, respectively) for 4 weeks. Left ventricular AngII receptors were measured by radioligand binding assays using [125I]-[Sar1,Ile8]-AngII in plasma membrane fractions from these four groups. The AT1 and AT2 receptors were distinguished using their specific antagonists CV 11974 and PD 123319, respectively. 3. The high-salt diet increased blood pressure and the left ventricle:bodyweight ratio in DS rats. However, neither Bmax for AT1 and AT2 receptors nor Kd for [125I]-[Sar1,Ile8]-AngII differed between the groups. These results are different from those of other reports of pressure-overload LVH, such as spontaneously hypertensive rats or renovascular hypertension rats, in which AT1 and AT2 receptors were reported to be up-regulated.

Animals↗

PubMedDate not supplied

Effect of the calcium channel blocker nilvadipine on urinary albumin excretion in hypertensive microalbuminuric patients with non-insulin-dependent diabetes mellitus.

A 24-week study was conducted to evaluate the effects of the dihydropyridine calcium channel blocker nilvadipine on urinary albumin excretion in eight microalbuminuric hypertensive patients with non-insulin-dependent (type II) diabetes mellitus. Blood pressure and urinary albumin excretion measurements before the administration of nilvadipine (8 mg) were compared with those after 4, 8, 12 and 24 weeks of treatment. No significant changes were observed in the mean values of haemoglobin A1C. Systolic blood pressure was significantly reduced from 174 +/- 23 mmHg before treatment to 144 +/- 13 mmHg after 24 weeks of treatment (P < 0.02). Diastolic blood pressure was significantly reduced from 93 +/- 11 mmHg at baseline to 79 +/- 8 mmHg after 24 weeks of treatment (P < 0.05). Urinary albumin excretion was significantly reduced from 65.4 +/- 37.4 mg/g creatinine at baseline to 51.6 +/- 41.1 mg/g creatinine (P < 0.05) after 4 weeks, and to 39.1 +/- 26.9 mg/g creatinine (P < 0.02) after 24 weeks of treatment. These data suggest that in hypertensive microalbuminuric patients with non-insulin-dependent diabetes mellitus, treatment of hypertension with the calcium blocker nilvadipine may slow the progression of diabetic nephropathy.

Aged↗