Serum immunoglobulin G concentration in Southern elephant seal, Mirounga leonina (Linnaeus, 1758), from Elephant island (Antarctica): Sexual and adrenal steroid hormones effects

• Published in: Veterinary immunology and immunopathology Vol. 106; no. 3; pp. 239 - 245
• Main Authors: Ferreira, Ana P.S., Martínez, Pablo E., Colares, Elton P., Robaldo, Ricardo B., Berne, Maria E.A., Miranda Filho, Kleber C., Bianchini, Adalto
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 15-07-2005
• Subjects: abiotic stress; adrenal cortex hormones; Adrenal Cortex Hormones - blood; adult animals; aldosterone; Aldosterone - blood; animal age; Animals; Antarctica; blood serum; cortisol; Elephantidae; Enzyme-Linked Immunosorbent Assay; estrogens; Estrogens - blood; Female; gender differences; Gonadal Steroid Hormones - blood; humoral immunity; Hydrocortisone - blood; Immunoglobulin G; Immunoglobulin G - blood; Male; Marine mammal; Mirounga; Mirounga leonina; Mirounga leonine; progesterone; Progesterone - blood; Radioimmunoassay; radioimmunoassays; seals; Seals, Earless - blood; Seals, Earless - growth & development; Seals, Earless - immunology; Sex Characteristics; Southern elephant seal; Steroid hormones; testosterone; Testosterone - blood; young animals; Marine mammal; Antarctica; Mirounga leonine; Immunoglobulin G; Steroid hormones; Southern elephant seal
• ISSN: 0165-2427; 1873-2534
• DOI: 10.1016/j.vetimm.2005.02.024

Serum immunoglobulin G (IgG; indirect enzyme-linked immunosorbent assay), as well as sexual and adrenal steroid hormones’ concentrations (radioimmunoassay) were determined in 63 (male and female) Southern elephant seals (
Mirounga leonine) at different developmental stages (weaned pups, juveniles and adults). In females, IgG values (mean
±
S.D.) were higher (
P
<
0.05) in adults (15.9
±
6.5
mg
ml
−1) than in juveniles (7.9
±
4.0
mg
ml
−1), but similar to weaned pups (12.0
±
5.0
mg
ml
−1). Estrogen concentration was higher (
P
<
0.05) in adults than in the weaned pups. In females, a significant (
P
<
0.05) correlation (
R
=
0.4) between serum IgG level and progesterone concentration was observed. In males, testosterone concentration was higher (
P
<
0.05) in adults than in the juveniles and weaned pups. Aldosterone and cortisol concentrations were higher (
P
<
0.05) in weaned pups (1056.0
±
643.1
pmol
l
−1 and 272.7
±
110.0
nmol
l
−1, respectively) than in the juveniles (638.6
±
579.7
pmol
l
−1 and 152.9
±
97.3
nmol
l
−1, respectively) and adults (386.5
±
209.1
pmol
l
−1 and 145.7
±
67.3
nmol
l
−1, respectively). These findings indicate that weaned pups are subjected to a higher natural stressful condition in the field. Despite this, humoral immunity, measured through IgG concentration, is not impaired in weaned pups.