Effects of Hypoxia on Vasopressin Concentrations in Cerebrospinal Fluid and Plasma of Sheep

Ri, Stark; Ss, Daniel; Mk, Husain; Ab, Zubrow; Ls, James

doi:10.1159/000123933

Cited by 19 publications

(5 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These sites include noncardiac vagal afferents as well as central nervous system receptors. [36][37][38][39][40][41][42][43] The rise of AVP in the presence of combined sinoaortic and cardiac denervation occurred in the presence of marked hypotension, which could have induced cerebral ischemia with concomitant AVP release.36'4042-44 In addition, a recent study by Wood et a145 demonstrated that in fetal sheep AVP responses to hemorrhage were related to changes in arterial pH, also suggesting that AVP release could be mediated by chemoreceptors. In that study, there were also no differences in the AVP responses to hemorrhage in the intact and vagotomized sheep.45 Furthermore, it has been proposed that nicotinic synapses in the central nervous system have an important role in mediating AVP release in response to hypotension.46,47 Because these pathways can be inhibited by ganglionic blockade,46,47 we examined a subset of intact dogs with ganglionic blockade in response to hemorrhage.…”

Section: Discussionmentioning

confidence: 99%

Relative roles of cardiac and arterial baroreceptors in vasopressin regulation during hemorrhage in conscious dogs.

Shen

Cowley

Vatner

1991

Circulation Research

View full text Add to dashboard Cite

To determine the relative roles of cardiac and sinoaortic baroreceptors in mediation of arginine vasopressin (AVP) release, hemorrhage was performed in five groups of conscious splenectomized dogs: 1) all nerves intact; 2) either chronic surgical or acute pharmacological (intrapericardial lidocaine) cardiac denervation (CD); 3) chronic sinoarotic denervation (SAD); 4) combined chronic sinoartic denervation plus either chronic or acute cardiac denervation (SAD + CD); and 5) all nerves intact, but with ganglionic blockade. Hemorrhage (0.5 ml/min/kg) reduced mean arterial pressure similarly in the intact and CD groups. Decreases in mean arterial pressure were augmented in SAD, SAD + CD, and ganglion-blocked groups compared with responses in intact and CD groups. There were no differences in responses of plasma AVP to hemorrhage in the intact and CD groups, but the AVP response was significantly blunted in the SAD + CD group as compared with SAD alone. When compared during the early stage of hemorrhage, at the same reduction in mean arterial pressure, the rise in AVP was greater in the ganglion-blocked group than in the SAD + CD group, but was less than in the intact group. With a protocol to reduce mean arterial pressure by 20 mm Hg over the same period (42 +/- 0.6 minutes) in four of the groups, the blood volume required to reduce mean arterial pressure by 20 mm Hg was similar in the intact (20 +/- 1 ml/kg) and CD (21 +/- 1 ml/kg) groups, but was less in the SAD (12 +/- 1 ml/kg) and SAD + CD (12 +/- 1 ml/kg) groups. Again, similar increases were observed in AVP between the intact (50 +/- 9 pg/ml) and CD (51 +/- 9 pg/ml) groups, whereas increases in AVP were diminished in the SAD (11 +/- 3 pg/ml) and SAD + CD (7 +/- 2 pg/ml) groups. In the presence of an AVP antagonist, decreases in mean arterial pressure and increases in total peripheral resistance with hemorrhage were affected similarly in both the intact and CD groups, whereas hemodynamic impairment by AVP blockade was less marked in the SAD and SAD + CD groups. These results indicate that cardiac receptors are not the major regulators of AVP release during progressive hemorrhage in conscious dogs. However, when the complicating influences of sinoaortic reflexes were eliminated, a modest role for cardiac receptors was uncovered.

show abstract

Section: Discussionmentioning

confidence: 99%

Relative roles of cardiac and arterial baroreceptors in vasopressin regulation during hemorrhage in conscious dogs.

Shen

Cowley

Vatner

1991

Circulation Research

View full text Add to dashboard Cite

show abstract

“…occurs in measurable amounts in the cerebrospinal fluid (CSF) of several species. A rise in the osmolality of the extracellular fluid [7,24], severe hemorrhage [25], and hy poxia [23] cause AVP levels to increase in both the systemic circulation and in the CSF. A prominent diurnal rhythm has been demonstrated for AVP in the CSF of cats and monkeys 118, 19], rats [17,21], and recently in that of rabbits [12].…”

mentioning

confidence: 99%

Vasopressin Levels in the Cerebrospinal Fluid in Rats of Different Age and Sex

Jolkkonen¹,

Tuomisto²,

et al. 1986

Neuroendocrinology

View full text Add to dashboard Cite

In male and female rats of two different age groups, we measured the arginine-vasopressin (AVP) levels in cerebrospinal fluid (CSF) collected at different times of the day. Mean values of AVP in cisternal CSF averaged across the different times of the day were higher in males than in females (p = 0.02), and in young (2 months) than in aged (12 months) rats (p = 0.03) of both sexes. The AVP levels in CSF showed a clear circadian rhythm in both young and aged male rats; the values at 07.00 h and 13.00 h were higher than those at 01.00 h and 19.00 h. The amplitude of the rhythm was smaller in females than in males. In addition, the rhythm was more pronounced in young than in aged rats of both sexes. These data suggest that both age and sex affect levels of vasopressin in CSF.

show abstract

“…These stimuli include hypoxia, hemorrhage, shock, emesis, and intracranial hypertension. 7 -11 -34 - 37 Our results imply that these plasma levels of vasopressin have marked effects on blood flow to the choroid plexus.…”

Section: Functional Implicationsmentioning

confidence: 68%

Humoral regulation of blood flow to choroid plexus: role of arginine vasopressin.

Faraci

Mayhan

Farrell

et al. 1988

Circulation Research

View full text Add to dashboard Cite

The goal of this study was to examine humoral mechanisms that regulate blood flow to the choroid plexus. We determined the effects of arginine vasopressin on blood flow (microspheres) to the choroid plexus in anesthetized and awake rabbits. In anesthetized rabbits, blood flow to the choroid plexus was 342 +/- 31 (mean +/- SEM) ml/min/100 g under control conditions. Intravenous infusion of vasopressin at 4 and 40 mU/kg increased plasma vasopressin levels from 11 +/- 1 to 55 +/- 15 and 441 +/- 120 pg/ml, respectively, and blood flow to the choroid plexus decreased by 48 +/- 6% and 70 +/- 4%. Cerebral blood flow was not affected by infusion of vasopressin. Similar responses to infusion of vasopressin were observed in awake rabbits. The V1 antagonist [d(CH2)5Tyr(Me)AVP] (10 micrograms/kg i.v.) had no effect on resting blood flow, but abolished the effect of vasopressin on blood flow to the choroid plexus. Vasoconstrictor responses of the choroid plexus to intravenous infusion of phenylephrine were not attenuated by the V1 antagonist. Thus, circulating vasopressin, at plasma levels that are observed under physiological and pathophysiological conditions, has marked effects on blood flow to the choroid plexus. These effects appear to be mediated through a V1 receptor. We speculate that vasopressin may play an important role in regulation of blood flow to the choroid plexus and perhaps in the regulation of cerebrospinal fluid production.

show abstract

Effects of Hypoxia on Vasopressin Concentrations in Cerebrospinal Fluid and Plasma of Sheep

Cited by 19 publications

References 18 publications

Relative roles of cardiac and arterial baroreceptors in vasopressin regulation during hemorrhage in conscious dogs.

Relative roles of cardiac and arterial baroreceptors in vasopressin regulation during hemorrhage in conscious dogs.

Vasopressin Levels in the Cerebrospinal Fluid in Rats of Different Age and Sex

Humoral regulation of blood flow to choroid plexus: role of arginine vasopressin.

Contact Info

Product

Resources

About