Trying to understand the cardiac staircase effect, and the role of estrogen and progesterone in relation.
-
Hello all,
I posted this question in the "Ray Peat X" community on twitter, but it's a bit dead, so I'm going to re-post the question here:
"I'm trying to look into Peat's claim about estrogen, progesterone, and their effects on the heart. His claim (in the attached picture) is referencing a study by Szent-Gyorgyi that I can't find, and I've tried looking around.
The rest of the article is fine, the estrogen and negative ino- and lusitropic effects on the heart are correct, but the argument that progesterone is positively ino- and lusitropic is something I can't find in contemporary literature, other than some niche cases.
Here are the studies/books I've reviewed, with a summary of each.
(Sitzler et al., 1996 + Filice et al., 2011) Negative ino- and lusitropy of estrogen on the heart (human)
(CSAPO & CORNER, 1952) Estrogen builds the staircase effect in uterus, progesterone doesn't (rabbit)
(Rubin & Salter, 1952) Progesterone exhibits small negative inotropy (cat, guinea pig, frog)
(Cheng et al., 2012) Progesterone accelerates repolarization and protects against drug-induced proarrhythmic effects (rabbit)
(Hajdu & Szent-Gyorgyi, 1952) This was the text I thought Peat was citing, although no examination of sex hormones was done (frog)
️(CHEMICAL PHYSIOLOGY OF CONTRACTION IN BODY AND HEART MUSCLE, Szent-Gyorgyi, 1953) Negative staircase effect of progesterone (frog)
Obviously, progesterone inhibiting the staircase effect in the uterus is expected and desired, but in the heart, it seems to also exhibit at least a small amount of inhibition.
Maybe I'm misunderstanding the statement, but I can't find any papers talking about positive lusi- or inotropic effects of prog. I can't find the study by Szent-Gyorgi on RABBIT heart with progesterone and estrogen, only uterine studies. Plz anyone halp.
Bibliography:
Cheng, J., Zhang, J., Ma, X., & Su, D. (2012). Frequency-dependent acceleration of cardiac repolarization by progesterone underlying its cardiac protection against drug-induced proarrhythmic effects in female rabbits. European Journal of Pharmacology, 689(1–3), 172–178. https://doi.org/10.1016/j.ejphar.2012.05.052
CSAPO, A. I., & CORNER, G. W. (1952). THE ANTAGONISTIC EFFECTS OF ESTROGEN AND PROGESTERONE ON THE STAIRCASE PHENOMENON IN UTERINE MUSCLE. Endocrinology, 51(5), 378–385. https://doi.org/10.1210/endo-51-5-378
Filice, E., Angelone, T., De Francesco, E. M., Pellegrino, D., Maggiolini, M., & Cerra, M. C. (2011). Crucial Role of Phospholamban Phosphorylation and S-Nitrosylation in the Negative Lusitropism Induced by 17β-estradiol in the Male Rat Heart. Cellular Physiology and Biochemistry, 28(1), 41–52. https://doi.org/10.1159/000331712
Hajdu, S., & Szent-Gyorgyi, A. (1952). Action of DOC and serum on the frog heart. The American Journal of Physiology, 168(1), 159–170. https://doi.org/10.1152/ajplegacy.1951.168.1.159
Rubin, B., & Salter, W. T. (1952). THE EFFECTS OF PROGESTERONE AND SOME RELATED STEROIDS ON THE CONTRACTION OF ISOLATED MYOCARDIUM. The Journal of Pharmacology and Experimental Therapeutics, 105(4), 443–449. https://doi.org/10.1016/S0022-3565(25)05095-5
Sitzler, G., Lenz, O., Kilter, H., La Rosee, K., & Böhm, M. (1996). Investigation of the negative inotropic effects of 17β-oestradiol in human isolated myocardial tissues. British Journal of Pharmacology, 119(1), 43–48. https://doi.org/10.1111/j.1476-5381.1996.tb15675.x" -
Inferred from effect on intracellular ca and somewhat known similarity between smol critters and failing hearts?
https://doi.org/10.1016/j.hlc.2004.08.006
What's that story about the frog that turned in to a prince from a shock, later revised to a loving act. (Sorry I'm like this.)
@8f4 said in Trying to understand the cardiac staircase effect, and the role of estrogen and progesterone in relation.:
Maybe I'm misunderstanding the statement
You're not, in my opinion.
I posted this question in the "Ray Peat X" community on twitter, but it's a bit dead
Maybe you could start a fire.
I'm trying to look into Peat's claim about estrogen, progesterone, and their effects on the heart.
Why? And what is 8f4. Are you a microbiologist? (ff to decline.)
-
@8f4 I also couldn't find this study. Is it possible Ray was in correspondence with ASG and this was an unpublished work? I also couldn't find a similar study via a Selye search (under the theory that Ray typoed the wrong Hungarian).
It wouldn't surprise me if Szent-Gyorgyi and Selye hypothesized and/or tested this together as the idea would be a combination of parts of each's philosophy. But again, no evidence. I couldn't fund anything in the Selye's In Vivo book for which ASG wrote a forward.
-
@Homo_normalis Another good candidate could be the book "Chemical Physiology of Contraction in Body and Heart Muscle" 1953. I can't get access to it. Maybe someone else has it and can search?
-
@Homo_normalis said in Trying to understand the cardiac staircase effect, and the role of estrogen and progesterone in relation.:
under the theory that Ray typoed the wrong Hungarian
Not the only "typo" on that site.
