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Prolactin's role during acute and chronic heat stress in growing pigs
Author(s) -
Sanz-Fernandez Maria Victoria,
Pearce S. C.,
Upah N. C.,
Long L. R.,
Nayeri A.,
Sucu E.,
Gabler N. K.,
Patience J. F.,
Hsu W. H.,
Rhoads R. P.,
Baumgard L. H.
Publication year - 2012
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.26.1_supplement.1079.7
Subject(s) - prolactin , medicine , endocrinology , zoology , crossbreed , biology , chemistry , hormone
Heat stress (HS) increases circulating prolactin (PRL) in a variety of animal models (reasons remain unknown), but whether or not HS elevates PRL in growing pigs is ill‐defined. Crossbred gilts (77±2 kg) were housed in individual pens and allocated to treatments: 1) HS conditions (36°C; 50% humidity) and ad libitum feeding (n=13) or 2) thermo‐neutral (TN) conditions (19°C; 61% humidity) and pair‐feeding (n=16) to eliminate the confounding effects of dissimilar feed intake. Pigs were sacrificed at d1 or 7 of environmental exposure. Rectal temperatures (Tr) and respiratory rates (RR) were obtained 4X daily and blood and intestinal tissues harvested at death. HS pigs had increased Tr ( P <0.01; 40.1 vs. 38.4°C), RR ( P <0.01; 111 vs. 36 bpm) and reduced feed intake ( P <0.05; 57%). By design, TN pigs’ intake mirrored the HS pattern. PRL was higher ( P <0.05) in HS pigs (0.97 vs. 0.64 ng/ml). In acute HS (24 h), PRL was negatively correlated with feed intake (r = −0.71; P <0.05), ileal transepithelial resistance (TER; r = −0.85; P <0.01) and tended to be negatively correlated with colonic TER (r = −0.69; P =0.06). In chronic HS (d7), PRL tended to be only inversely correlated with glucose (r = −0.81; P <0.10). In TN pigs, PRL was not correlated with any of the measured variables. Together, PRL appears to participate in both the acute HS response and the acclimation to chronic environmental hyperthermia. Heat stress, prolactin USDA/AFRI