The expression of hyperpolarization activated cyclic nucleotide gated (HCN) channels in the rat ovary are dependent on the type of cell and the reproductive age of the animal: a laboratory investigation.
BACKGROUND
Aim of this study was to test the hypothesis that levels of hyperpolarization activated cyclic nucleotide gated channels 1 to 4 (HCN1-4) are linked to the reproductive age of the ovary.


METHODS
Young, adult, and reproductively aged ovaries were collected from Sprague-Dawley rats. RT-PCR and western blot analysis of ovaries was performed to investigate the presence of mRNA and total protein for HCN1-4. Immunohistochemistry with semiquantitative H score analysis was performed using whole ovarian histologic sections.


RESULTS
RT-PCR analysis showed the presence of mRNA for HCN1-4. Western blot analysis revealed HCN1-3 proteins in all ages of ovarian tissues. Immunohistochemistry with H score analysis demonstrated distinct age-related changes in patterns of HCN1-3 in the oocytes, granulosa cells, theca cells, and corpora lutea. HCN4 was present only in the oocytes, with declining levels during the reproduction lifespan.


CONCLUSIONS
The evidence presented here demonstrates cell-type and developmental age patterns of HCN1-4 channel expression in rat ovaries. Based on this, we hypothesize that HCN channels have functional significance in rat ovaries and may have changing roles in reproductive aging.
Yeh
John
J
Department of Gynecology-Obstetrics, University at Buffalo, The State University of New York, Buffalo, New York 14222, USA. jyeh@buffalo.edu
Kim
Beom Su
BS
Gaines
Larry
L
Peresie
Jennifer
J
Page
Carly
C
Arroyo
Armando
A
D000367:Age Factors; D000818:Animals; D015153:Blotting, Western; D054815:Cyclic Nucleotide-Gated Cation Channels / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D005260:Female; D015870:Gene Expression; D064428:Hyperpolarization-Activated Cyclic Nucleotide-Gated Channels; D007150:Immunohistochemistry; D007473:Ion Channels / Q000032:analysis / Q000235:genetics / Q000378:metabolism; D010053:Ovary / Q000166:cytology / Q000378:metabolism*; D015221:Potassium Channels / Q000032:analysis / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012098:Reproduction / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction
D054815:Cyclic Nucleotide-Gated Cation Channels; C513835:HCN3 protein, rat; C513836:HCN4 protein, rat; C578667:Hcn1 protein, rat; D064428:Hyperpolarization-Activated Cyclic Nucleotide-Gated Channels; D007473:Ion Channels; D015221:Potassium Channels; D012333:RNA, Messenger