Effect of bacterial lipopolysaccharide on the reproductive axis of prepubertal and peripubertal female rats. Ontogenic changes in the immune-neuroendocrine interactions.
The immune, endocrine and nervous systems are closely interrelated, which allows the organism to respond to different types of stress such as infection. Chronic infectious and inflammatory conditions are often accompanied by an impaired reproductive function. Leptin, a hormone produced by adipose tissue, exerts a regulatory function on the reproductive axis. It has homology with other proinflammatory cytokines and could be modified by lipopolysaccharide (LPS). Therefore, these studies were designed to investigate the effect of LPS administration on the neuroendocrine mechanisms involved in the regulation of the reproductive axis during sexual maturation. Fifteen- and 30-day-old female rats were injected with a single dose of LPS 250 microg/kg (i.p.) and then nitric oxide synthase (NOS) activity, hypothalamic excitatory/inhibitory amino acids and Gn-RH content, serum LH and leptin concentration were studied. In 15-day-old female rats LPS treatment did not modify hypothalamic inducible (iNOS) and constitutive (cNOS) NOS activity, Gn-RH, glutamate (GLU) and GABA content. Also serum LH and leptin levels were not modified. In 30-day-old rats LPS increased iNOS and cNOS activity (p < 0.001) and hypothalamic Gn-RH content (p < 0.001). At this age hypothalamic GABA content was significantly decreased (p < 0.001) without changes in GLU content, and serum LH (p < 0.001) and leptin (p < 0.0001) decreased significantly. In summary, current studies have demonstrated that LPS administration to 15- and 30-day-old female rats results in a different response of the hypothalamus-pituitary-gonadal axis and of the adipose tissue, demonstrating an ontogenic response of the immune-neuroendocrine system to LPS administration.
Reynoso
Roxana
R
Laboratory of Endocrinology, Department of Physiology, School of Medicine, University of Buenos Aires, Buenos Aires, Argentina. rreynoso@fmed.uba.ar
Ponzo
Osvaldo
O
Cardoso
Nancy
N
Szwarcfarb
Berta
B
Carbone
Silvia
S
Moguilevsky
Jaime
J
Scacchi
Pablo
P
D000273:Adipose Tissue / Q000276:immunology / Q000378:metabolism; D000375:Aging / Q000276:immunology / Q000378:metabolism; D000818:Animals; D001424:Bacterial Infections / Q000276:immunology*; D005260:Female; D018698:Glutamic Acid / Q000276:immunology / Q000378:metabolism; D007987:Gonadotropin-Releasing Hormone / Q000276:immunology / Q000378:metabolism; D007030:Hypothalamo-Hypophyseal System / Q000276:immunology / Q000378:metabolism; D007031:Hypothalamus / Q000276:immunology / Q000378:metabolism; D018836:Inflammation Mediators / Q000494:pharmacology; D020738:Leptin / Q000097:blood / Q000276:immunology*; D008070:Lipopolysaccharides / Q000494:pharmacology; D007986:Luteinizing Hormone / Q000097:blood / Q000276:immunology; D015213:Neuroimmunomodulation / Q000276:immunology*; D009490:Neurosecretory Systems / Q000276:immunology* / Q000378:metabolism / Q000503:physiopathology; D019001:Nitric Oxide Synthase / Q000276:immunology / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D012098:Reproduction / Q000276:immunology*; D012741:Sexual Maturation / Q000276:immunology*; D013312:Stress, Physiological / Q000276:immunology / Q000378:metabolism / Q000503:physiopathology; D015854:Up-Regulation / Q000276:immunology; D005680:gamma-Aminobutyric Acid / Q000276:immunology / Q000378:metabolism
D018836:Inflammation Mediators; D020738:Leptin; D008070:Lipopolysaccharides; D007987:Gonadotropin-Releasing Hormone; D018698:Glutamic Acid; D005680:gamma-Aminobutyric Acid; D007986:Luteinizing Hormone; D019001:Nitric Oxide Synthase