Effect of hyperoxia, hypercapnia, and hypoxia on blood-cerebrospinal fluid barrier

Abstract

The effect was evaluated in puppies and adult dogs by measuring the rate of passage of radioactive iodinated human serum albumin from plasma into the cerebrospinal fluid and by determining the plasma and cerebrospinal fluid glutamic oxalacetic transaminase and lactic dehydrogenase activities. Arterial O2 concentration and saturation, CO2, and pH determinations were obtained. In puppies, hypercapnia was associated with marked respiratory acidosis and produced a great increase in the rate of transfer of albumin I131 from plasma to cerebrospinal fluid. Prolonged hypoxia also produced a definite increase in permeability of the blood-cerebrospinal fluid barrier. Increased concentration ratios of cerebrospinal fluid enzyme activity/plasma enzyme activity were observed in both groups. Hypoxia alone did not cause significant changes. In adult dogs, hypercapnia or hypoxia did not result in comparable findings.

Cortical pH and the blood‐brain barrier

“…The resistance of the acidic response to 10 % (v/v) C02 agrees with the barrier resistance to trypan blue (Clemedson, Hartelius & Holmberg, 1958), to 24Na (Fishman, 1959), and to albumin (Lending et al 1961). …”

“…Such a passive barrier has been proposed for restriction of organic ions (Brodie, Kurz & Schanker, 1960), and may exist also for trypan blue (Broman & Lindberg-Broman, 1945), for albumin (Lending, Slobody & Mestern, 1961), for fluorescein (Baldwin, Galindo & Farrier, 1962) and for 35P phosphate (Ernster & Herlin, 1961).…”

“…The barrier to trypan blue was found in the foetus of the rat (Grazer & Clemente, 1957) and of man (Gr6ntroft, 1954), and the barrier to albumin in the puppy (Lending et at. 1961).…”

The effect of hypercapnia on a blood‐brain barrier mechanism in foetal and new‐born sheep.

“…Previous authors (e.g. Clemsden, Hartelius & Holmberg, 1958;Lending et al 1961) working with adult animals have usually ascribed the effect of hypercapnia in increasing the level of markers penetrating from blood into brain and c.s.f. to an effect upon blood-brain or bloodc.s.f.…”

Mechanisms of Drug Absorption and Excretion Passage of Drugs in and out of the Central Nervous System

“…At the higher concentrations of CO2, some damage to the cerebral vessels was ob served. Lending and co-workers studied the effect of inhalation of 7 per cent CO2 on the entry of radioiodinated serum albumin into CSF in puppies and adult dogs (59). In puppies, inhalation of 7 per cent C02 for 30 min caused a severe acidosis (plasma pH 6.86) and increased 20-fold the entry of the radioiodinated serum albumin into CSF at 30 min.…”