January 3rd, 2007 by The Bosphorus
Wikipedia says:
Relaxin interacts with the relaxin receptor LGR7 and 8 which belong to the G-protein-coupled receptor superfamily. They contain a heptahelical transmembrane domain and a large glycosylated ectodomain, distantly related to the receptors for the glycoproteohormones, such as the LH-receptor or FSH-receptor. Relaxin receptors have been found in the heart, smooth muscle, the connective tissue, and central and autonomous nervous system.
Ah, pregnancy…
January 3rd, 2007 at 10:35 pm
Yeah Bos, sounds really nice… until your hip falls out of joint while cooking supper just because you shift your weight a little bit.
There are many wonderful things about pregnancy, but I recall that as being one of the more troublesome. Be nice to her.
January 3rd, 2007 at 10:35 pm
I understand what this says, but I’m not sure where you’re going with it . . .
January 3rd, 2007 at 10:39 pm
Uh, netmom, I’m not sure how you reconcile your comment with this:
” . . . in humans its peak is reached during the first trimester, not toward the end of pregnancy.”
I mean, be nice to Eaves (pregnant or not), but I’m not clear on how relaxin is relevant to hip dislocations in the third trimester.
Just sayin’
January 3rd, 2007 at 11:41 pm
Is that why you involuntarily pee on yourself when your pregnant? :-)
January 4th, 2007 at 6:25 am
Joel, Most of the sites I found on loose joints point to relaxin as a culprit.
January 4th, 2007 at 7:51 am
” . . . in humans its peak is reached during the first trimester, not toward the end of pregnancy.”
Well, it may not be at its peak in the third trimester, but the effects are still quite noticable!
January 4th, 2007 at 8:11 am
I think we are misreading this. I think Bos is trying to tell us he’s pregnant!
I think the involuntary pee thing is probably more related to some little person inside using the bladder as a soccer ball. Or they just get to a point where they don’t care and just tell us “oh dear, that was ‘involuntary’ Honey, the dog peed on the floor again.”
January 4th, 2007 at 9:05 am
Joel, the production or levels may be highest at an earlier point, but the effects are greatest at the end stage, because the whole purpose is to allow some “give” in the pelvic ligaments for delivery.
I won’t argue biochemistry with you, but pregnancy and delivery is one area where I have considerably more firsthand experience than you do.
January 4th, 2007 at 9:20 am
“the effects are greatest at the end stage, because the whole purpose is to allow some “give” in the pelvic ligaments for delivery.”
I understand the theory. However, as a biochemist, arguments based on teleology don’t hold much water. I see how it *could* work that way, I just don’t see the evidence that it *does* work that way. Doesn’t look to me like the relaxin titers are high enough in late pregnancy.
“pregnancy and delivery is one area where I have considerably more firsthand experience than you do.”
Heh. Well, I probably have more experience driving than you do netmom, but that doesn’t make me any more of a car mechanic than the fact that you gave birth four times makes you an expert in the endocrinology of pregnancy. You’ll have to do better than that.
“Most of the sites I found on loose joints point to relaxin as a culprit.”
I found several sites that made this assertion too, bos. One of the tricks in using the internet to research science is to identify authoritative sites. The more authoritative sites I visited seemed more equivocal on this point. Doesn’t mean it isn’t true, but color me skeptical at this point. Skepticism is an important job skill in my line of work.
January 4th, 2007 at 11:36 am
Sitting on those exercise balls really helped the pain in my hips and back when I was pregnant.
Relaxin is released mostly in the first trimester but surges throughout the pregancy and also helps get the cervix ready for birth. The reason why it is felt more in the last trimester is because of a surge keeping the baby from moving too much and because of all the extra weight you are carrying. Once you get pregnant Joel maybe you will understand.
“Hormonal surges (relaxin and estrogen)—pregnancy related hormones can cause problems by creating joint laxity, especially in the pelvis. These hormonal surges, along with the additional weight and change in center of gravity, contribute to decreased joint support.”
January 4th, 2007 at 12:44 pm
Yeah, I recall the discomfort my wife felt when she was pregnant 19 years ago. Before she was pregnant, she was 105 lbs, the extra ca. 25 lbs certainly made for some discomfort. Still, she worked right up to the start of contractions.
January 4th, 2007 at 7:57 pm
You know, I did really understand how this whole kid gets out of the mom thing until I saw it first hand. Never heard of Relaxin till now. But there wasn’t much Relax’n (pun ha)about my wife’s pregnancy. With all the books and classes and all that birth ball, water birth, and all that it just pretty much came down to the moment — what worked good. Wife had a pretty good idea when it was happening what worked and what didn’t. She used a hybrid of sitting up, rocking, and making some very strange devil like noises. It seemed to have worked for her. In fact too well. She got the famous line from the male OB — “stop pushing!” And she pretty much looked up and said with her face “what?!” Joel, they are superhuman with the Relaxin and hormones — just look at the floor and walk away . . . it doesn’t matter how it works. I swear that my wife could have bent street signs with her pinky in labor. Maybe just by looking at them. I don’t know. Just don’t step between her and a well timed epidural or there will be hell to pay.
January 4th, 2007 at 10:05 pm
Yeah, my lovely and talented wife was all about the epidural. She was having contractions for two days. Episiotomy, forceps, it all worked out. I was glad to be there.