PT  - JOURNAL ARTICLE
AU  - J F Aubert
AU  - M Burnier
AU  - B Waeber
AU  - J Nussberger
AU  - H R Brunner
TI  - Nicotine-induced release of vasopressin in the conscious rat: role of opioid peptides and hemodynamic effects.
DP  - 1987 Nov 01
TA  - Journal of Pharmacology and Experimental Therapeutics
PG  - 681--685
VI  - 243
IP  - 2
4099  - http://jpet.aspetjournals.org/content/243/2/681.short
4100  - http://jpet.aspetjournals.org/content/243/2/681.full
SO  - J Pharmacol Exp Ther1987 Nov 01; 243
AB  - Nicotine has been shown to stimulate the release of vasopressin and to cause significant hemodynamic changes. The mechanisms leading to enhanced vasopressin secretion and the vascular consequences of the high plasma vasopressin levels during nicotine infusion have not yet been determined. Therefore, the purposes of the present study were 1) to examine in normal conscious rats the role of opioid peptides in the nicotine-induced increase in plasma vasopressin levels and 2) to assess the role of vasopressin in the hemodynamic effects of nicotine (20 micrograms/min for 15 min) using a specific V1 antagonist of the vascular actions of vasopressin. Plasma vasopressin levels were significantly increased in the nicotine-treated animals (39.5 +/- 10 vs. 3.7 +/- 0.6 pg/ml in the controls, P less than .01). Pretreatment with naloxone, an antagonist of opioids at their receptors, did not reduce the vasopressin levels (47.7 +/- 9 pg/ml). Nicotine also increased mean blood pressure (122.5 +/- 2.5 to 145.2 +/- 3.3 mm Hg, P less than .01) and decreased heart rate (461 +/- 6 to 386 +/- 14.5 beats/min, P less than .05). Administration of the vasopressin V1 antagonist before the nicotine infusion did not affect the systemic hemodynamics or the regional blood flow distribution, as assessed by radiolabeled microspheres. Thus, these results suggest that the nicotine-induced secretion of vasopressin is not mediated by opioid receptors and that the high plasma vasopressin levels do not exert any significant hemodynamic effect on cardiac output or blood flow distribution.