title: Neonatal sympathetic denervation alters the development of in vitro spleen cell proliferation and differentiation.
abstract: The ontogeny of spleen cell proliferation to T and B cell mitogens and immunoglobulin secretion, measured in vitro, was examined in neonatally sympathectomized Fischer 344 (F344) rats, administered the neurotoxic drug 6-hydroxydopamine (6-OHDA) from 1 to 3 days of age. Compared to cells from age-matched controls, spleen cells from neonatally sympathectomized animals, aged 7-14 days, exhibited a shift in the proliferative response to the T cell mitogen, concanavalin A (Con A), with reduced proliferation in the presence of low doses of Con A, but increased proliferation with higher doses. During the same period, from 7 to 14 days, the B cell mitogen STM/DxS inhibited proliferation by spleen cells from all rats, and no effect of sympathectomy was observed. As adult-like patterns of mitogen responsiveness emerged from 21 to 42 days of age, neonatally sympathectomized rats showed reduced proliferative responses of both T and B cells. This effect dissipated by 56 days of age. Polyclonal immunoglobulin (Ig) production by B cells was assessed in vitro in the presence or absence of STM/DxS. Neonatal sympathectomy resulted in reduced spontaneous IgM production throughout development. From 28 to 42 days of age, when mitogen-triggered IgM secretion first developed, neonatal sympathectomy decreased the magnitude of the response. By 56 days of age, mitogen-induced IgM secretion was no longer affected by sympathectomy, similar to the proliferative response. Gender influenced the time course of sympathectomy-induced changes in spleen cell proliferation and differentiation; however, the magnitude and direction of these changes were similar in both males and females. Desipramine, administered prior to 6-OHDA, prevented both sympathetic denervation and the 6-OHDA-induced changes in spleen cell responsiveness. This indicates that the alterations in immune function were dependent on NA nerve fiber destruction and were not simply the result of direct 6-OHDA action on other cells. The results of this study suggest that sympathetic innervation may play an important potentiating role in the development of the lymphoid system, through effects on lymphocyte proliferation and differentiation.
authors.affiliation: Department of Neurobiology and Anatomy, University of Rochester School of Medicine and Dentistry, New York 14642.
authors.forename: K D
authors.initials: KD
authors.lastname: Ackerman
authors.forename: K S
authors.initials: KS
authors.lastname: Madden
authors.forename: S
authors.initials: S
authors.lastname: Livnat
authors.forename: S Y
authors.initials: SY
authors.lastname: Felten
authors.forename: D L
authors.initials: DL
authors.lastname: Felten
mesh_terms: D000818:Animals; D000831:Animals, Newborn / Q000276:immunology* / Q000502:physiology; D000917:Antibody Formation; D002454:Cell Differentiation; D002455:Cell Division; D005260:Female; D007075:Immunoglobulin M / Q000096:biosynthesis; D008213:Lymphocyte Activation / Q000187:drug effects; D016131:Lymphocyte Subsets / Q000166:cytology* / Q000276:immunology; D008297:Male; D008934:Mitogens / Q000494:pharmacology; D009638:Norepinephrine / Q000032:analysis / Q000502:physiology*; D009928:Organ Specificity; D016627:Oxidopamine; D051381:Rats; D011916:Rats, Inbred F344 / Q000254:growth & development / Q000276:immunology; D012737:Sex Factors; D013154:Spleen / Q000737:chemistry / Q000166:cytology* / Q000276:immunology; D013563:Sympathectomy, Chemical
chemical_list: D007075:Immunoglobulin M; D008934:Mitogens; D016627:Oxidopamine; D009638:Norepinephrine