Reduced responses of prolactin and catecholamine to stress in the lactating rat.
Prolactin, GH, TSH, adrenaline and noradrenaline responses to the stress of immobilization were compared between lactating and non-lactating dioestrous rats. The concentrations of GH in plasma were reduced to a similar degree by the immobilization of lactating and non-lactating rats, and TSH levels were unchanged in both groups. The increases in plasma concentrations of adrenaline and noradrenaline induced by stress were significantly smaller in lactating than in non-lactating rats. Immobilization caused a marked increase in prolactin levels in the plasma of non-lactating rats but no increase in lactating rats. These changes may help to save energy and maintain milk production during the period of lactation.
Higuchi
T
T
Department of Physiology, Fukui Medical School, Japan.
Negoro
H
H
Arita
J
J
D000818:Animals; D004837:Epinephrine / Q000097:blood*; D005260:Female; D013006:Growth Hormone / Q000097:blood; D007103:Immobilization; D007774:Lactation / Q000097:blood* / Q000523:psychology; D009638:Norepinephrine / Q000097:blood*; D011247:Pregnancy; D011388:Prolactin / Q000097:blood*; D051381:Rats; D011919:Rats, Inbred Strains; D013315:Stress, Psychological / Q000097:blood*; D013972:Thyrotropin / Q000097:blood
D011388:Prolactin; D013972:Thyrotropin; D013006:Growth Hormone; D009638:Norepinephrine; D004837:Epinephrine