[Osmoregulating effect of vasopressin with prolonged action on Brattleboro rats with hypothalamic diabetes insipidus].

The particularities of urine osmotic concentration depending on hormonal background of vasopressin were studied in rats. It was found that WAG and Brattleboro lines of rats characterized respectively by normal level and absence of endogenous vasopressin, possess interline correlation of urine osmolality (p = 0.86) in various conditions between the extreme hydrating and dehydratation. Concentrating level of WAG rats varies from 747 +/- 94 to 2936 +/- 128 mOsm/kg, but that of Brattleboro rats changes more within the 160 +/- 9 being twice lower as isotonicity to 1305 +/- 142 mOcm/kg. Urine concentrating goes up to 1391 +/- 76 mOcm/kg in Brattleboro rats already on the day of the action of exogenous vasopressin secreted from ALZET minipump, however, in spite of constant work of this minipump during 4 hrs a week, further increasing of urine osmolality was not observed in Brattleboro rats.

Oral DDAVP is a good alternative therapy for patients with central diabetes insipidus: experience of five-year treatment.

We studied the efficacy and safety of oral 1-deamino-8-D-arginine-vasopressin (DDAVP) tablets in 9 patients, aged 17-36 years, with central diabetes insipidus (DI). The tablet contained 100 microg of desmopressin acetate. Maximum plasma concentration was obtained at 90 min after a single oral administration of 100 microg DDAVP with a mean plasma level of 14.7 +/- 5.4 (range: 5.3-50.9) pg/ml. The onset of action was observed 2 h after oral administration, while the maximum effect was obtained at 4 h. Mean urine volume in patients decreased significantly from 402 +/- 52 to 26 +/- 3 ml/hr and urine osmolality increased from 91 +/- 8 to 732 +/- 21 mosm/kg at 4 h after the intake of oral DDAVP. Plasma osmolality level and serum sodium concentration remained unchanged throughout the study. Long-term treatment for 5 years with oral DDAVP resulted in control of diuresis in 8 of the 9 patients. The average oral DDAVP dose required to obtain this control was 19 +/- 2 (range: 15-30) times more than that of prior intranasal treatment. No adverse effects were observed during this follow-up period. These results indicate that oral DDAVP is a safe therapeutic agent that may be a good alternative treatment of central DI, particularly in patients who have chronic rhinitis and visual disturbances.