He calculates he has served more than 40,000 bottles of wine since his career as artist and gallery owner began. A kind of sommelier of the arts, Steve Mendelson celebrated the 40th anniversary of Mendelson Gallery with a party May 2.

His gallery on Ellsworth Avenue in Shadyside was once a bordello, giving it a pedigree as colorful as that of its owner. All the vino pouring began in Rome in 1974 with a guy named Not Vital (pronounced note VEEtall).

"I was juggling and doing mime as a street performer in the Piazza Navona when I met this crazy Swiss artist and sculptor who also owned a circus.

"I like to say we discovered each other."

Mr. Vital was just the right kind of eccentric who has always caught the attention of Mr. Mendelson, and the two have been friends ever since.

"I opened a gallery at first because I was an artist and wanted to exhibit my own work," he said.

Understanding it couldn't always be a one-man show, he started cultivating artists from here and abroad.

"I gave Not his first exhibition in the United States," he said. "He wouldn't be who he is today without me and I wouldn't be who I am."

Mr. Vital is a man at the peak of his professional popularity right now, evidenced by an article in The New York Times last month about his latest project.

"Vital bought a marble island in Patagonia in the middle of a glacier lake just to drill a hole through the middle to watch the sunset," said Mr. Mendelson, who recently returned from visiting his friend on the island he named NotOna.

"You have to fly three hours south of Santiago, then drive five hours on dirt roads, then take a boat for 45 minutes to the middle of the lake where the island is," he recounted.

The artist hired six out-of-work miners for five years to dig a 150-foot tunnel. A window at the end allows him to watch the sunset.

"It seems frivolous and crazy, but at the same time he was supporting an entire village. It was a beautiful thing for him to do," said Mr. Mendelson.

Not just a peddler of paintings, the gallery owner sees his role as nurturing artists and their causes.

"I have been to Agadez, Niger, where he constructed a tower to watch the sunset in the middle of the Sahara Desert. But he also built a school for the children," he said.

When he is not getting his passport stamped, Mr. Mendelson lives above the gallery.

"I have always been a seeker of peak experiences," he explained, surrounded by relics of his world travels and a personal art collection that began when he left college at 20 to wander around India.

Mr. Mendelson has spent the better part of his professional career on a genuine mission to find and promote artists who elevate and inspire. But it may not have always been perceived that way.

"When I tell someone I'm a friend of Steve Mendelson, I never get a neutral response. People either love him or hate him, but everyone seems to have an opinion!" said Alan Perer, a friend and client.

Never one to worry about others' opinions, Mr. Mendelson sees it as a positive.

"If most people disagree with me, I must be doing something right! In Paris they would call me a 'provocateur.' "

He does not see himself as flawless, however.

"Sure, there have been mistakes and compromises. Sometimes, I low-browed the Pittsburgh community with commercial choices in a quest to keep the gallery alive," he confessed.

Then there were the artists who turned out to be economic adventurers, looking to exploit the market, he said.

The current show marking his four decades in the business features the work of more than 24 artists, including Mr. Vital, Harry Schwalb, Jack Weiss, Ron Desmett, Kathleen Mulcahy, Thad Mosley, David Lewis and Cynthia Cooley. He also shows his own work.

A peripatetic truth seeker, Mr. Mendelson is most at home when leaving home. "I feel an immediate sigh of relief on a plane," he admitted.

It was conducive to operating a gallery in Paris for three years.

"I'll be the first to admit that enough was never enough. Impatient, spoiled by my successes, I whined through the decades that I was underappreciated, my artists under-supported, the press never wrote enough, blah blah blah ...."

Mellowed a bit, Mr. Mendelson continues to be excited by art and what it represents. On a recent First Friday in Garfield, he stopped by a gallery where he had donated artwork to stop fracking under public parks.

"I was amazed and gratified to see hundreds of people, tattooed, pierced or otherwise, imbibing on art and culture. Passing through one of the spaces, crammed with people 'as young as I used to be,' I was taken by the work of Jason Woolslare. We have since been in touch, and who knows? I may be able to help a young art teacher who wants to be a full-time artist find his way."

Mr. Mendelson is a dream chaser who has dined with celebrities including Andy Warhol, Jean-Michel Basquiat, Margaux Hemingway, Keith Haring and David Hockney. He has been working on an autobiography for the past 40 years.

"It might be described as 'Eat, Pray, Love' with testicles," he said, laughing.

He's met a pope and been a pauper and at 63 he is looking forward to more discoveries for himself and his gallery on Ellsworth.

First Published: May 12, 2014, 4:00 a.m.