Patricia A Broderick1, Lauren B Malave2. 1. Department of Physiology, Pharmacology, and Neuroscience, Sophie Davis School of Biomedical Education , City College of New York, New York, New York. ; Department of Biology, City University of New York Graduate Center , New York, New York. ; Center for Advanced Technology (CAT), City University of New York , New York, New York. ; Department of Neurology, NYU Langone Medical Center , New York, New York. 2. Department of Physiology, Pharmacology, and Neuroscience, Sophie Davis School of Biomedical Education , City College of New York, New York, New York. ; Department of Biology, City University of New York Graduate Center , New York, New York. ; Center for Advanced Technology (CAT), City University of New York , New York, New York.
Abstract
Background: Sex differences in cocaine abuse are well established. Females have a higher sensitivity and thus higher vulnerability to cocaine abuse compared to males. There are many studies showing that sensitivity to cocaine reward varies during the estrus cycle. Methods: Vaginal smears were examined through a DIFF staining kit and viewed through a microscope to determine the estrus cycle stage. Smears were taken immediately before and after cocaine and/or caffeine injections. Furthermore, we suggest a new tool to analyze the estrus cycle by using electrical resistance of the vaginal mucosa. Results: In the present study, we discovered that cocaine directly induced changes in the estrus cycle. Interestingly, caffeine did not affect the estrus cycle and nor did the combination of cocaine and caffeine. We observed that caffeine blocked the cocaine-induced estrus cycle changes using conventional exfoliate cytology. Therefore, caffeine may have neuroprotective properties on the changes induced by cocaine. Conclusion: These phase changes in the estrus cycle may be the underlying cause of sex differences in cocaine addiction that can be blocked by caffeine. Thus, we propose a valuable insight into sex differences in cocaine abuse and reveal a possible treatment with antagonizing the adenosine system.
Background: Sex differences in cocaine abuse are well established. Females have a higher sensitivity and thus higher vulnerability to cocaine abuse compared to males. There are many studies showing that sensitivity to cocaine reward varies during the estrus cycle. Methods: Vaginal smears were examined through a DIFF staining kit and viewed through a microscope to determine the estrus cycle stage. Smears were taken immediately before and after cocaine and/or caffeine injections. Furthermore, we suggest a new tool to analyze the estrus cycle by using electrical resistance of the vaginal mucosa. Results: In the present study, we discovered that cocaine directly induced changes in the estrus cycle. Interestingly, caffeine did not affect the estrus cycle and nor did the combination of cocaine and caffeine. We observed that caffeine blocked the cocaine-induced estrus cycle changes using conventional exfoliate cytology. Therefore, caffeine may have neuroprotective properties on the changes induced by cocaine. Conclusion: These phase changes in the estrus cycle may be the underlying cause of sex differences in cocaine addiction that can be blocked by caffeine. Thus, we propose a valuable insight into sex differences in cocaine abuse and reveal a possible treatment with antagonizing the adenosine system.
Authors: Tod E Kippin; Rita A Fuchs; Ritu H Mehta; Jordan M Case; Macon P Parker; Heather A Bimonte-Nelson; Ronald E See Journal: Psychopharmacology (Berl) Date: 2005-10-19 Impact factor: 4.530