GPCR Question for Hormones

[Clmed162]

Hi all, I'm a bit confused about the GPCR pathway for hormones. I thought that only peptide hormones would undergo the GPCR pathway since they bind to membrane receptors and cause an intracellular cascade. However, Google says that "G-protein-coupled receptors (GPCRs) are involved in animal steroid hormone signaling, but their mechanism is unclear." So do both steroid hormones and peptide hormones rely on second messengers then?

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[JimKimSlim]

For the scope of MCAT, your understanding will suffice. Peptide for surface receptors, like GPCR, and steroid for nuclear, like estrogen receptor.