Effect of methadone on plasma arginine vasopressin level and urine production in conscious dogs

Abstract

The aim of this study was to examine the effect of i.v. methadone on the plasma arginine-vasopressin (AVP) levels and urine production in 9 conscious dogs. A highly significant increase from the baseline plasma AVP values of below 3 pg/ml occurred within 5 min following methadone administration. Maximum levels were reached within 30-50 min post-injection and varied from 18.5 to 100 pg/ml. A significant decrease in urine production was not seen under these experimental conditions. Mean arterial blood pressure did not change significantly during the experiment. Apart from the partial influence of the methadone-induced respiratory acidosis, we postulate a direct relationship between i.v. administration of methadone and the increased plasma AVP levels in dogs.Methadone; Arginine-vasopressin; (Dog)

Osmolality-regulated arginine vasopressin release in conscious dogs. Evidence for dopaminergic or opioid modulation?

“…Infusion of hypertonic saline caused a similar, relative increase in plasma osmolality and plasma Na+ concentration (Table 1) (Szilagyi & Fer¬ rarlo 1986;Hellebrekers et al 1987), whereas at the high-dose level, naloxone was reported to in¬ crease the osmotic responsiveness of AVP (Wade 1985). Bromocriptine was administered at a dose, shown effectively to suppress pituitary interme¬ diate lobe secretion of prolactin (Janssens 1986).…”

“…A VP extraction and radioimmunoassay Full details of the AVP extraction and radioimmuno¬ assay were described by us previously (Hellebrekers et al 1987). In short, plasma AVP was extracted using reversed-phase columns of octylsilane (C8) bonded silica gel (J. T. Baker Chemical Co, Phillipsburg, NJ).…”

Cardiovascular effects of a proprietary l-methadone/fenpipramide combination (Polamivet) alone and in addition to acepromazine in healthy Beagle dogs

“…As a second mechanism of methadone induced bradycardia an increased baroreceptor activity secondary to increased vascular resistance mediated by elevation of arginine vasopressin plasma levels has been proposed (Hellebrekers et al. 1987, 1989).…”

“…2007). In contrast, methadone has been shown to increase systemic vascular resistance and arterial blood pressure (Hellebrekers et al. 1987, 1989; Maiante et al.…”

“…Acepromazine reduces blood pressure due to vasodilation, which is mediated by peripheral alpha-adrenergic blockade and depression of the hypothalamic vasomotor centre (Thurmon et al 2007). In contrast, methadone has been shown to increase systemic vascular resistance and arterial blood pressure (Hellebrekers et al 1987(Hellebrekers et al , 1989Maiante et al 2009). However, a combination of both drugs did not induce significant changes in systolic arterial pressure (Monteiro et al 2008).…”