Differential transport of rat and human interleukin-1alpha across the blood-brain barrier and blood-testis barrier in rats.
Human interleukin-1alpha is transported across the murine blood-brain barrier (BBB) and blood-testis barrier (BTB) by a saturable transport system. Differences in the biological activity and binding of human IL-1 in mouse and rat brain raise the possibility of species differences in the transport of IL-1 across the BBB and BTB. We measured the transport of recombinant human 125I-IL-1alpha (I-huIL-1alpha) and rat 125I-IL-1alpha (I-ratIL-1alpha) across the rat BBB and BTB after intravenous injection using a sensitive in vivo technique and film autoradiography. I-ratIL-1alpha was found to cross the rat BBB and rat BTB at rates comparable to those reported previously for murine IL-1alpha in mice. Passage across the BBB was inhibited by the addition of unlabeled rat IL-1alpha, demonstrating saturable transport. In contrast, I-huIL-1alpha entered the brain of the rat much more slowly, and its entry was not inhibited by the addition of unlabeled human IL-1alpha. These results show that the rat interleukin-1 transporter, unlike the murine transporter, does not transport human IL-1alpha. This difference highlights the importance of species specificity in IL-1alpha transport and may partly explain the different physiological responses to exogenous human IL-1alpha among rodent species.
Plotkin
S R
SR
Partners Neurology Program, Harvard Medical School,Boston, MA 02115, USA.
Banks
W A
WA
Maness
L M
LM
Kastin
A J
AJ
D000818:Animals; D001812:Blood-Brain Barrier / Q000502:physiology*; D001814:Blood-Testis Barrier / Q000502:physiology*; D006801:Humans; D007375:Interleukin-1 / Q000493:pharmacokinetics*; D008297:Male; D051379:Mice; D051381:Rats; D017207:Rats, Sprague-Dawley; D013045:Species Specificity
D007375:Interleukin-1