Talk:Bathmotropic

Explanation of correction for hypo/hypercalcemia

The Wikipedia article in its current state (as of February 17th, 2013) has an error regarding the effects of hypo/hypercalcemia. This article states (correctly) that a positive bathmotropic effect increases the response of muscles to stimulation. However, this article states (incorrectly) that hypercalcemia has a positive bathmotropic effect and also states (incorrectly) that hypocalcemia has a negative bathmotropic effect. For anyone who is not already familiar with this subject, you can refer to the signs and symptoms of hyper/hypocalcemia.

For quick reference, hypercalcemia causes (among other things) fatigue and muscle weakness, consistent with a negative bathmotropic effect (since muscle fibers become more difficult to stimulate, not as many will be activated with a given muscle stimulus, thus effective muscle strength is decreased). Meanwhile, hypocalcemia causes (among other things) tetany and spasms, consistent with a positive bathmotropic effect (since muscle fibers become easier to simulate, they may be activated with slight muscle stimulus, or even with no stimulus at all).

In addition, this article has completely bogus explanations for why these two conditions were switched. This article states (incorrectly) that hypocalcemia causes decreased membrane permeability to sodium; this article even references a PubMed journal which states exactly the opposite! I've re-linked the journal here for convenience. This Wikipedia article also states that hypercalcemia causes partial depolarization of the resting membrane potential, but the only reference is to the same PubMed article which states the opposite, stating that increased calcium causes hyperpolarization rather than depolarization.

I determined that this error was introduced by 69.121.130.59 on November 6th, 2012, when the two words had their places switched. It's unclear whether or not it was vandalism or just a misunderstanding. To be fair, when considering the role of calcium in synapses and with troponin, it seems unlikely that hyper/hypocalcemia would have the effects that they have. It only makes sense once the role of calcium in blocking sodium channels is understood. I spent a day trying to understand that, and finally stumbled upon this article and thus found the reference I've already mentioned.

I have now fixed the article to accurately reflect its references. -NorsemanII (talk) 18:47, 17 February 2013 (UTC)