Effects of l-deprenyl treatment on noradrenergic innervation and immune reactivity in lymphoid organs of young F344 rats

• Published in: Journal of neuroimmunology 1999-04, Vol.96 (1), p.57-65
• Main Authors: ThyagaRajan, S., Madden, K.S., Stevens, S.Y., Felten, D.L.
• Format: Article
• Language: English
• Subjects: Adrenergic Fibers - chemistry; Adrenergic Fibers - immunology; Animals; B-Lymphocytes - chemistry; B-Lymphocytes - cytology; B-Lymphocytes - drug effects; CD5 antigen; CD5 Antigens - analysis; Cell Division - immunology; Concanavalin A - pharmacology; deprenyl; Enteric Nervous System - chemistry; Enteric Nervous System - immunology; Flow Cytometry; Interleukin-2; Interleukin-2 - immunology; Killer Cells, Natural - chemistry; Killer Cells, Natural - cytology; Killer Cells, Natural - drug effects; Lymph Nodes - immunology; Lymph Nodes - innervation; Lymphocyte proliferation; Lymphoid Tissue - immunology; Lymphoid Tissue - innervation; Male; Mesenteric lymph nodes; Neuroprotective Agents - pharmacology; NK cell activity; Norepinephrine; Norepinephrine - analysis; Norepinephrine - immunology; Rats; Rats, Inbred F344; Selegiline - pharmacology; Spleen; Spleen - immunology; Spleen - innervation; T-Lymphocytes - chemistry; T-Lymphocytes - cytology; T-Lymphocytes - drug effects; Thymus; Thymus Gland - immunology; Thymus Gland - innervation
• ISSN: 0165-5728; 1872-8421
• DOI: 10.1016/S0165-5728(99)00017-X

Sympathetic noradrenergic (NA) neuronal activities in the thymus, spleen and mesenteric lymph nodes (MLN) and immune responses in the spleen were examined in young male F344 rats treated daily with 0, 0.25 mg, or 2.5 mg/kg body weight of l-deprenyl, an irreversible monoamine oxidase-B (MAO-B) inhibitor. Rats were treated daily for 1, 15, or 30 days, and sacrificed 7 days after the last deprenyl treatment. Deprenyl treatment increased norepinephrine (NE) content in the spleen without modifying the pattern and density of NA innervation in the splenic white pulp. The concentration of NE was unaltered in the thymus, but it was increased in the MLN of deprenyl-treated rats. One day of treatment with deprenyl decreased splenic NK cell activity while 15 days of deprenyl treatment enhanced splenic NK cell activity. Deprenyl elevated Con A-induced T lymphocyte proliferation following 30 days of treatment, but did not alter spleen cell Con A-induced IL-2 production or the percentage of CD5+ T cells in the spleen. A moderate decrease in the percentage of sIgM+ B cells was observed in the spleens of 15- and 30-day deprenyl-treated rats. These results suggest that deprenyl has sympathomimetic action on sympathetic NA nerve fibers in the spleen; the enhancement of NA neuronal activity may contribute to the modulation of immune responses in the spleen.