Splenocyte blastogenesis suppressed in rats implanted with an osmotic pump.
Rats implanted subcutaneously with an empty osmotic pump connected by a polyethylene catheter to a jugular vein for 5 to 10 days evinced a decreased splenocyte responsiveness to blastogenic stimulation in vitro to bacterial lipopolysaccharide, a known B cell stimulator, as well as to the plant mitogens pokeweed mitogen (PWM), a known stimulator of T and B cells, and Concanavilan A, a known T cell stimulator. The surface of the implanted pumps became infiltrated with lymphoid cells, especially macrophages. Suppression of blastogenic responsiveness after implantation for 10 days with an empty pump or even a pump dispensing pyrogen free saline only in a continuous manner was nearly as marked as that which occurred at 2-5 days after continuous infusion with endotoxin. These depressed blastogenic responses, although less, were also evident when rats were implanted with a catheter into a jugular vein connected by means of a swivel to either an empty pump or one dispensing pyrogen free saline. Suppression of blastogenic responsiveness was not related to alteration in serum complement or corticosteroid levels. Since administration of immunomodulatory substances systemically to individuals often involves implantation of an osmotic pump, investigation into the mechanisms of lymphoid cell suppression associated with an implanted pump itself has potential significance.
Pross
S
S
Department of Medical Microbiology and Immunology, University of South Florida College of Medicine, Tampa.
Newton
C
C
Widen
R
R
Klein
T W
TW
Friedman
H
H
Spitzer
J A
JA
D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology; D015918:Infusion Pumps, Implantable; D008070:Lipopolysaccharides; D008213:Lymphocyte Activation / Q000276:immunology*; D008297:Male; D008934:Mitogens; D051381:Rats; D011919:Rats, Inbred Strains; D013154:Spleen / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology
D008070:Lipopolysaccharides; D008934:Mitogens