Previous works led us to propose that peripheral iodothyronine deiodination is mainly regulated by the reciprocal interaction between the thyroid and the sympathetic nervous system (SNS). In this study, we analyzed the role suckling exerts, through SNS activation, upon deiodination of thyronines in liver, heart, brown adipose tissue and mammary gland during lactation. Our results showed that resuckling causes a concurrent stimulatory response on deiodinase type 1 (D1) in heart and mammary gland, but not in liver and brown adipose tissue. The stimulatory response was mimicked by norepinephrine and by the beta-adrenergic agonist isoproterenol, through the overexpression of the large form of D1 mRNA. These results suggested that, during lactation, peripheral thyronine deiodination is co-ordinated by the SNS, and suckling is a major modulatory influence.

This article has been cited by other articles:

				S C P Dutra, E G Moura, A L Rodrigues, P C Lisboa, I Bonomo, F P Toste, and M C F Passos Cold exposure restores the decrease in leptin receptors (OB-Rb) caused by neonatal leptin treatment in 30-day-old rats J. Endocrinol., November 1, 2007; 195(2): 351 - 358. [Abstract] [Full Text] [PDF]

				B Anguiano, R Rojas-Huidobro, G Delgado, and C Aceves Has the mammary gland a protective mechanism against overexposure to triiodothyronine during the peripartum period? The prolactin pulse down-regulates mammary type I deiodinase responsiveness to norepinephrine J. Endocrinol., November 1, 2004; 183(2): 267 - 277. [Abstract] [Full Text] [PDF]