Abstract
The purpose of this study was to determine if patterns of gonadotropin secretion during estrogen-induced luteinizing hormone (LH) surges are altered by abrupt changes in light exposure. When light intensity was increased approximately threefold, before the "critical period" or during the rising phase of the LH surge, serum LH increased significantly (P less than 0.01) compared to control values. Furthermore, LH surges were prolonged when exposure to light of high intensity was continued beyond the normal extent of the photophase. In contrast to the effects of increased light intensity, acute darkness did not alter the magnitude of LH surges compared with controls exposed to light of low intensity. Thus, phasic LH secretion is enhanced by abrupt increases in light intensity, and the duration of LH secretion can be extended by prolonging the photophase. Although LH surges occur in total darkness, this study suggests that light modulates the intensity of the signal for LH secretion by a stimulatory action.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
