Stimulation of Pituitary Prolactin and TSH Release in Lactating and Proestrous Rats¹

Nicotine Given Intracerebroventricularly Does Not Inhibit the Preovulatory Surge of LH and PRL Secretion in Female Rats.

“…This finding is the same as those in previous reports showing that a single nicotine iv or sc injection does not totally abolish the LH and PRL surge but causes an acute reduction in both LH and PRL concentrations after the injecton [1][2][3][4]. Taking the present finding that icy nicotine injection did not cause any changes in the surge secretion of these hormones, all of these studies seem to suggest that nicotine injected systemically causes the effects by acting on certain sites(s) other than the central nervous system, in other words the site of action of nicotine is not on the GnRH surge generator, which is presumably in the preoptic area.…”

“…IT WAS early found that, in female rats, nicotine injected subcutaneously (sc), i.e., systemically, delayed the preovulatory surge of both LH and PRL secretion on the day of proestrus [1][2][3][4], although tobacco smoke delayed only the LH surge [5]. The LH surge advanced by progesterone injection in the morning of proestrus was also inhibited by nicotine injected intraperitonearly (ip) [6].…”

Pituitary and Serum Levels of Prolactin (PRL), Thyroid Stimulating Hormone (TSH) and Serum Thyroxine (T4) in Hereditary Dwarf Rats (<I>rdw/rdw</I>)

“…Although a similar tendency was observed, namely that the value of rdw/N x 100 was remarkably low for the serum PRL, this slight discrepancy may be due to the method of blood sampling. [3,23].…”

Prolactin and the physiological regulation of its secretion. A review

“…TRH has been shown to potentiate PRL release from lactotrophs in a dose-dependent manner both in vitro and in vivo experiments (Bowers et al, 1971;Tashjian et al, 1971;Blake, 1974). It can successfully promote pituitary PRL secretion in oestrogen-primed male rats (Piercy and Shin, 1980), but not in normal male or lactating female (Grosvenor and Mena, 1980;Piercy and Shin, 1980;Riskind et al, 1984).…”