Vasopressin in plasma and cerebrospinal fluid of dogs during hypoxia or acidosis

Abstract

Hypoxia and hypercapnia have been shown to cause an increase in the concentration of vasopressin in plasma, but their effects on vasopressin in cerebrospinal fluid (CSF) are not known. In addition, the effect of metabolic acidosis on plasma and CSF vasopressin has not been reported. In this study, plasma and CSF vasopressin levels were measured in anesthetized dogs subjected to either hypoxia, hypercapnia, or metabolic acidosis. Rate and depth of respiration were closely regulated with the aid of muscle paralysis and mechanical ventilation. Vasopressin increased markedly in both plasma and CSF during severe hypoxia (10% O2) and during hypercapnia (10% CO2) but did not change during either mild (15% O2) or moderate (12.5% O2) hypoxia. Although mild hypoxia by itself did not affect either plasma or CSF vasopressin, it did potentiate the increase in plasma and CSF vasopressin that was induced by severe hypercapnia, thus suggesting that hypoxia and hypercapnia may exert synergistic effects on vasopressin secretion. Metabolic acidosis produced by slow intravenous infusion of 1 N hydrochloric acid decreased arterial pH to values comparable to those induced by hypercapnia and increased vasopressin in plasma; CSF vasopressin was unchanged. These results are consistent with the concept that the source of vasopressin secreted into plasma may be different from that secreted into CSF.

Vasopressin and Catecholamine Secretion during Metabolic Acidemia in the Ovine Fetus

“…Thus, it appears that the increase in fetal AVP secretion is probably reflective of the exposure of the fetus to NH4Cl and that metabolic acidosis, as induced in the present paradigm, actually had little or no effect. Our results are in sharp contrast with those of Wang et al (28) who observed in anesthetized adult dogs a 20-fold rise in plasma AVP concentrations following hydrochloric acid infusions that decreased the arterial pH from 7.38 to 7.05. Nevertheless, since these changes in arterial pH were comparable to those obtained during induced hypercap nia, where AVP release was considered mild (-3-fold), these investigators suggested that factors other than the simple increase 42 FAUCHE R ET AL.…”

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

“…The AVP elevating properties of a hypercapnic and acidotic state have been well substantiated (Raft et al, 1983;Rose et al, 1984;Wang et al, 1984), although the 4.75-fold increase in AVP levels recorded in similar states of hypercapnic acidosis (Rose et al, 1985) is less than the rise we now saw. Considering the difference in magnitude of response and the difference in time course between plasma AVP levels ( fig.…”

Body-core temperature decreases during hypoxic hypoxia in Long–Evans and Brattleboro rats

“…However, they do provide indirect evidence that an increase in central AVP may delay the return of Th to control levels following hypoxic hypoxia. Wang et al (1984) have shown that plasma and cerebrospinal levels of AVP are higher at 60 than at 38 min during ventilation of adult anesthetized dogs with 10% oxygen. En their experiments, plasma AVP returned toward control levels Can.…”

“…This is possible because hypoxemia stimulates the release of AVP into plasma of fetal and adult sheep (Alexander et a%. 1972;Rurak 1978), dogs (Forsling and Ullmann 1974;Raff et d. 1983), and cats (Forsling and Bees 1975), and into the cerebrospinal fluid of fetal and adult sheep (Stark et d. 1984(Stark et d. , 1985 and dogs (Wang et a%. 1984).…”