November 12, 2007

Frog Pregnancy Test
Lima, Peru

At dinner tonight Tatiana's mother was telling the story about how they used her urine in conjunction with a frog to test if she was pregnant, back in the 70s.


Amazed, I dug this up, and wanted to share:

How do you use a frog to test for a baby?

You inject some urine into its dorsal lymph sac in the morning and check back at the end of the day. A dose of a pregnant woman's pee will cause a female South African clawed frog to lay eggs within eight to 12 hours. The test also works on male frogs, which produce sperm in response to the injection.

The frog test works because a pregnant woman's urine contains a hormone called human chorionic gonadotropin, or hCG. Most modern pregnancy tests rely on the detection of hCG using other means: The standard home test kit, for example, flags hCG with prepared antibodies. But until the 1960s, the best way to detect the hormone was to inject urine into an animal and wait to see what happened.

when I heard the story, the mental image that came to mind was a woman urinating on a frog and the skin changing color! (laughing) I just can't imagine how anyone ever figured this one out…



November 16th, 2007

Because of its similarity to luteinizing horomone (LH), hCG can also be used clinically to induce ovulation in the ovaries as well as testosterone production in the testes. As the most abundant biological source is women who are presently pregnant, some organizations collect urine from gravidae to extract hCG for use in fertility treatment.

In females, at the time of menstruation, FSH initiates follicular growth, specifically affecting granulosa cells. With the rise in estrogens, LH receptors are also expressed on the maturing follicle that produces an increasing amount of estradiol. Eventually at the time of the maturation of the follicle, the estrogen rise leads via the hypothalamic interface to the “positive feed-back” effect, a release of LH over a 24-48 hour period. This 'LH surge' triggers ovulation hereby not only releasing the egg, but also initiating the conversion of the residual follicle into a corpus luteum that, in turn, produces progesterone to prepare the endometrium for a possible implantation. LH is necessary to maintain luteal function for the first two weeks. In case of a pregnancy luteal function will be further maintained by the action of hCG from the newly established pregnancy.

Apparently they used South African clawed frogs because they can lay eggs year-round.

Nice scientific/medical find, Craig. A tidbit of history I was not aware of.

The United States


March 30th, 2012

How amazing it is ,this shows that we are attached with natur'

Note: Comments are open to everyone. To reduce spam and reward regular contributors, only submissions from first-time commenters and/or those containing hyperlinks are moderated, and will appear after approval. Hateful or off-topic remarks are subject to pruning. Your e-mail address will never be publicly disclosed or abused.