Hunter S. Thompson also wrote about it in Fear & Loathing in Las Vegas. His... "lawyer", talks about cutting "adrenaline glands" from someone to suck out the adrenochrome.

(emphasis added)

“What is it?"
“Adrenochrome,” he said. “You won't need much. Just a little tiny taste.” I got the bottle and dipped the head of a paper match into it.

“That's about right,” he said. “That stuff makes pure mescaline seem like ginger beer. You'll go completely crazy if you take too much.” I licked the end of the match. “Where'd you get this?” I asked. “You can't buy it."

“Never mind,” he said. “It's absolutely pure.” I shook my head sadly.

“Jesus! What kind of monster client have you picked up this time? There's only one source for this stuff...

He nodded.

“The adrenaline glands from a living human body,” I said. “It's no good if you get it out of a corpse."

“I know,” he replied. “But the guy didn't have any cash. He's one of these Satanism freaks. He offered me human blood—said it would make me higher than I'd ever been in my life,” he laughed. “I thought he was kidding, so I told him I'd just as soon have an ounce or so of pure adrenochrome—or maybe just a fresh adrenaline gland to chew on.” I could already feel the stuff working on me. The first wave felt like a combination of mescaline and methedrmne.

“Yeah,” my attorney was saying. “They nailed this guy for child molesting, but he swears he didn't do it

This was in the early early 70s. How many politicians were in power back in the 70s and still in power now?