Thank you for the clarification. I guess the above statement is the one that I’m having the most confusion with. I understand that hormones metabolize to become pheromones. What I don’t understand is whether those hormones can be sprayed on the skin, diffuse in the air, and communicate to another individual of the same species. I know there is a lot of emphasis on olfactory pathways when it comes to pheromone contact, however there are other organisms that use pheromones effectively but do not have olfactory pathways.
So naturally after learning about hormone receptors in the skin, I begin to wonder if our theory on pheromones is too narrow. Perhaps there are other forms of chemical communication between species that may mot be classified as pheromones however have the same effect.
Some studies reported that they could not rule out absorption through the skin, but I don’t think that anyone ever showed pheromones could act via skin absorption. In contrast, testosterone and other steroid hormones are now effectively delivered via topical applications. Organisms that do not have olfactory pathways but communicate through chemical exchanges, are indeed common. But to my knowledge none of the organisms you may be thinking about have skin.
If you look far enough you will find that in these skinless organisms the channels for communication via pheromones are very much the same as the channels used in the olfactory pathways of mammals. See for example the information on G-protein coupled pathways.
Also, my colleague and co-author of a 1996 Hormones and Behavior paper has suggested that immune system cells are involved in chemical communication, and that sex differences in these cells can be communicated via the nasal mucosa of mammals, including humans. Even now, she is probably 5-10 years ahead of the data in this regard, but that’s not unusual for her. As it has turned out, recent findings show that we, with Milton Diamond, were about 14 years ahead of the current data when we published the paper linked here: From fertilization to adult sexual behavior. [Horm Behav. 1996] - PubMed result If you read what we said about epigenetics, I think you will see what I mean, since the term has become a buzzword among biologists.
Progress is being made in this regard, and I hope to publish a follow-up article, perhaps even in the same journal. But if you continue to learn about pheromones as you have been, you might beat me to it. Thanks for you questions and comments.