Urinary Arginine Vasopressin in Asthma: Consideration of Fluid Therapy

To elucidate the role of antidiuretic hormone (ADH) on water and electrolyte balance in patients with asthmatic attacks, urinary arginine vasopressin (AVP) was assayed in 28 asthmatic patients. In a 3-year-old girl with status asthmaticus who developed a grand mal seizure in association with hyponatremia, urinary AVP levels remained high and fluctuated before convulsion; the cause of the convulsion was considered to be water intoxication due to inappropriate ADH secretion. In 19 of 28 patients with moderately severe asthmatic attacks, increases in urinary AVP levels occurred before treatment (300 ± 80 pg/ml vs. 40 ± 24 pg/ml (normal controls), p < 0.01); elvated AVP levels tended to fall in response to intravenous fluid therapy (appropriate ADH secretion) in 2 of 6 patients, but did not fall (inappropriate ADH secretion) in the remaining patients. It is concluded that inappropriate ADH secretion may occur in asthmatic attacks, and that in such a condition there seems to be a potential risk of water intoxication during fluid therapy, as demonstrated in the present patient.     

Oral urea for the treatment of chronic syndrome of inappropriate antidiuresis in children

We report the successful use of oral urea in the management of children with chronic syndrome of inappropriate antidiuretic hormone secretion (SIAD). We performed a retrospective review of four children with chronic SIAD. After initial attempts at management with fluid restriction, each was started on a 30% to 50% oral urea solution, and the dose was titrated until normal serum sodium was achieved. Fluid intake was liberalized after serum sodium normalization. All four children normalized their serum sodium. No side effects or toxicities were experienced. Oral urea is a safe, effective treatment for chronic SIAD in children.     

Gender-related effects of prenatal administration of estrogen and progesterone receptor antagonists on VEGF and surfactant-proteins and on alveolarisation in the developing piglet lung

Background

Vascular endothelial growth factor (VEGF) is essential for embryonic lung development and has been shown to be regulated by estradiol (E2) and progesterone (P).

Aim

To investigate the effects of prenatal E2 and P withdrawal by specific receptor antagonists on the mRNA expression of VEGF, surfactant proteins (SP-B and SP-C) and on alveolarisation in lung tissue of male and female pig fetuses.

Methods

Fetuses from 10 sows were randomized to receive either both an intramuscular injection of the E2 receptor blocker ICI 182.780 and the P receptor blocker RTI 3021-022 (ICI + RTI, n = 5) or a placebo injection (n = 5) at 90 days of gestation (DOG, 115 = term). After delivery by cesarean section on 114 DOG, tissue of the left lingula of the piglet's lung (28 placebo, 26 ICI + RTI) was obtained to determine the mRNA expression of VEGF, SP-B and SP-C. Lungs from 15 placebo and 14 ICI + RTI group piglets were removed and alveolar counts performed.

Results

The ICI + RTI group showed significantly lower SP-C mRNA expression and alveolar counts compared to the placebo group (p = 0.04 and 0.03, respectively). Diminished alveolarisation in the ICI + RTI group was mainly due to the reduction of alveolar counts in male piglets (p = 0.02). Within the placebo group VEGF and SP-B mRNA expression in male piglets were significantly lower compared to female piglets (p = 0.01 and 0.004, respectively). ICI + RTI treatment abolished this gender-related difference.

Conclusion

Estradiol and P antagonism affected gender-related differences of key proteins for pulmonary function and development and especially in males was associated with diminished alveolarisation.