What If Ovaries Don't Retire?

Menopause is generally thought of as the closing act of ovarian biology.

The follicles are gone. Or more accurately, there are not enough to continue the hormonal dance with the brain. Estrogen production plummets. Ovulation ends. The ovaries shrink and quietly fade into anatomical background. Just tiny little mummified monuments to youth.

I'm currently glad to have testicles. Because this sounds grim. And field reports from women and other ovary operators say it feels grim too.

However, the great shutdown may have a sliver lining. As we have learned, the body has a habit of refusing tidy endings. It likes things messy. Confusing even.

A fascinating bit of research suggests that the postmenopausal ovary may be changing jobs, as opposed to retiring.

Anatomy Tidbit: After menopause, ovaries typically decrease in size and can measure as small as 2 centimeters in diameter, compared to an average size of around 4 centimeters before menopause.

From Hormone Factory to Immune Headquarters?

Researchers studying aging mouse ovaries noticed something peculiar. As reproductive cells disappeared, immune cells flooded in.

And not just a handful.

Large populations of macrophages, dendritic cells, and other immune cell populations gradually occupied tissue that had once been dedicated almost exclusively to nurturing eggs. Even more intriguing, these immune cells weren't simply passing through. Gene expression studies suggested they were actively producing cytokines, chemokines, and other immune signaling molecules capable of communicating with the rest of the body.

Theis research floats the idea that perhaps the ovary undergoes an organ identity shift after reproduction ends. The ovarian tissue may transition toward functioning as an immune signaling organ.

A functional (and productive) midlife crisis, if you will.

Why Would This Happen?

One of the recurring themes in biology is that evolution is astonishingly economical. Cheap to the point of being detrimental in some cases. There's a lot of "that's good enough" and duct tape fixes found in the body.

This research speculates that after menopause, when ovarian follicles have largely disappeared, the remaining stromal tissue becomes an attractive environment for immune cells. This could serve several possible purposes and benefits.

Perhaps the ovary becomes an immune surveillance station.

Perhaps it helps coordinate inflammatory responses associated with aging.

Perhaps it assists in tissue repair.

Or Perhaps It's a Nothing Burger

While it isn't as interesting, all these immune calls could in fact just be chilling out, not doing much of anything. They could in fact be breaking down the ovary further or even causing problems of their own.

Here are a few "scientific bummers" to consider.

These experiments were performed primarily in mice. And mouse ovaries do share many biological features with human ovaries, but they are not identical. Human confirmation will require considerably more work.

Researchers observed immune activity and gene expression patterns. That doesn't automatically prove the organ has acquired a completely new physiological role.

An organ filled with immune cells isn't necessarily functioning as an immune organ.

Lest we forget...immune activity cuts both ways.

The aging immune system undergoes profound changes, including the development of chronic, low-grade inflammation, often called "inflammaging." Some of the immune signals coming from aging ovaries could ultimately prove protective. Others might contribute to age-related disease.

In the end we get to sit back and wait for MORE RESEARCH. And yes, I hate that phrase as much as you do. I want answers dammit.

Alas, science rarely works like that.

Want to read the study? Find it here.

https://academic.oup.com/molehr/advance-article-pdf/doi/10.1093/molehr/gaag038/68508299/gaag038.pdf