Vasoactive intestinal peptide can modulate immune and endocrine responses during lipopolysaccharide-induced acute inflammation.
OBJECTIVE
In many studies, it has been reported that vasoactive intestinal peptide (VIP) may play an important role in modulation of the immunological response. VIP can be produced by immunological cells, and also the receptors for this neuropeptide are present in many of these cells. The aim of our study was to estimate the effects of the administration of exogenous VIP on serum concentrations of proinflammatory cytokines [interleukin (IL)-6 and tumor necrosis factor (TNF)-alpha] and an anti-inflammatory cytokine (IL-10) during lipopolysaccharide (LPS)-induced acute inflammation. We also estimated the influence of VIP on pituitary [FSH, LH, TSH and prolactin (PRL)], thyroid (T3 and T4), adrenal (corticosterone) and gonadal (testosterone) hormones in response to LPS-induced acute inflammation.


METHODS
Male Wistar-Kyoto rats were divided into four groups, which received, respectively, placebo (0.9% NaCl), LPS, VIP and VIP with LPS. The TNF-alpha and IL-6 serum concentrations were measured after 2 h from the time of the administration of the agents, IL-10 was measured after 4 h, and the pituitary, thyroid, adrenal and gonadal hormone concentrations were measured after 2 and 4 h. Cytokine concentrations were estimated using ELISA tests, and hormone concentrations were measured using RIA tests.


RESULTS
In our experiments, LPS administration dramatically increased serum proinflammatory cytokine concentrations (TNF-alpha and IL-6) after 2 h and the anti-inflammatory cytokine (IL-10) after 4 h, as well as increasing the serum corticosterone concentration (after 2 and 4 h) and LH (after 2 h). LPS application decreased serum concentrations of T3 and TSH (both after 2 h), testosterone (after 2 and 4 h), FSH after 4 h and PRL after 4 h. VIP administration decreased the serum IL-10 concentration after 4 h and T3 concentration after 2 h and increased serum concentrations of FSH and corticosterone after 4 h. VIP administrated simultaneously with LPS decreased the LPS-induced increase in IL-6 and corticosterone concentrations (consecutively after 2 and 4 h). VIP also enhanced LPS-induced thyroid hormone (T3 and T4) suppression after 4 h and testosterone suppression after 4 h.


CONCLUSIONS
We conclude that VIP can modulate not only immune responses but also hormonal responses during acute inflammation.
Department of Internal Medicine, Endocrinology and Haematology, Central Hospital of Ministry of Home Affairs and Administration, Warsaw, Poland.
Wojciech
W
Bik
Ewa
E
Wolinska-Witort
Magdalena
M
Chmielowska
Agnieszka
A
Baranowska-Bik
Elzbieta
E
Rusiecka-Kuczalek
Boguslawa
B
Baranowska
D000208:Acute Disease; D000818:Animals; D016207:Cytokines / Q000097:blood / Q000187:drug effects; D004195:Disease Models, Animal; D015536:Down-Regulation / Q000187:drug effects / Q000276:immunology; D004703:Endocrine System / Q000187:drug effects* / Q000276:immunology; D006066:Gonads / Q000187:drug effects / Q000378:metabolism; D007030:Hypothalamo-Hypophyseal System / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D007107:Immune System / Q000187:drug effects* / Q000276:immunology; D007155:Immunologic Factors / Q000494:pharmacology*; D007249:Inflammation / Q000097:blood / Q000139:chemically induced / Q000276:immunology*; D008070:Lipopolysaccharides; D008297:Male; D010907:Pituitary Hormones / Q000378:metabolism; D010913:Pituitary-Adrenal System / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D011921:Rats, Inbred WKY; D013256:Steroids / Q000378:metabolism; D013961:Thyroid Gland / Q000187:drug effects / Q000378:metabolism; D015854:Up-Regulation / Q000187:drug effects / Q000276:immunology; D014660:Vasoactive Intestinal Peptide / Q000494:pharmacology*
D016207:Cytokines; D007155:Immunologic Factors; D008070:Lipopolysaccharides; D010907:Pituitary Hormones; D013256:Steroids; D014660:Vasoactive Intestinal Peptide