Dr. August Marshall Booth Jr., a researcher in the Department of Pharmacology at the University of Pittsburgh for 25 years, died of complications from ocular melanoma Monday at UPMC Shadyside. He was 72.

A native of Washington, D.C., Dr. Booth came to Pittsburgh in 1953 to attend Carnegie Institute of Technology, where he worked in the theater and the recording industry. A musician possessing a fascination with sound and drama, he left the school to become a stage hand and a lighting engineer for local productions.

He was the sound engineer for the cult horror classic "Night of the Living Dead," filmed in Pittsburgh in 1968, said Linda Carter Bell, his fiancee, of Squirrel Hill.

"It was a low-budget movie, and they were looking for cheap labor," Ms. Bell said of Dr. Booth's only venture into motion picture work. "He was willing to do it because he thought it would be fun."

But Dr. Booth's life was already moving in another direction, spurred by the loss of his first wife and son in an automobile accident in the mid-1960s.

"That absolutely changed his life," Ms. Bell said. "He went back to school at the University of Pittsburgh to complete his education," earning degrees in science and philosophy.

Dr. Booth joined Pitt's department of pharmacology, studying how the body deals with drugs. His main work dealt with how drugs affect the nervous system, how nerves communicate with muscles, and the automatic responses that the body makes that people don't think about. His particular focus was on bladder function and what controls it.

Dr. William C. de Groat, a longtime associate in Pitt's department of pharmacology, said Dr. Booth was a committed researcher whose skill with electronics resulted in valuable contributions in the laboratory, particularly in the study of the human nervous system.

"His insights led to advancements in the recovery of bladder functions after spinal cord injuries," Dr. de Groat said. "He spent a lot of time doing long experiments on the spinal cord, which would require 24, 48 hours of his working through the night. These weren't experiments where you could work 9 to 5."

Dr. John Lazo, chairman of the department of pharmacology for much of the time while Dr. Booth was there, said Dr. Booth was instrumental to the department's growth.

"During his period as part of the department, it grew tenfold and became one of the top 10 departments [in the nation]," Dr. Lazo said.

Dr. Booth's last published paper dealt with the bladder control of cats.

"We all learn to control our bladders," Dr. Lazo said. "Even dogs and cats learn this. And he studied, 'What's the wiring, the network that controls that, and then, when it breaks down, why does it break down?' He would try to understand how things worked, and how we control them."

The accident that claimed the lives of his first wife and son also led to Dr. Booth's passion for Mercedes Benz automobiles.

"He decided you didn't put your family in a car that wasn't safe," Ms. Bell said. "And, at the time, the Mercedes Benz was the safest car in the world."

Dr. Booth never bought new cars. He bought used ones and would repair them. He gained a reputation for knowing the inner workings of the diesel-powered cars and answered questions posed to him via the Internet from people around the world. His enthusiasm led to his being known as "Der Dieseling Doktor."

"He was a researcher," Ms. Bell said. "He went and researched Mercedes the same way he researched bladder and sexual function in the human male. He had a skill for finding information."

Survivors include two daughters, Sharon Murray Booth of Swissvale and Margaret Megan Gallek of Plum; and two grandsons.

A memorial service will be held at a later date. Donations may be made to the Hillman Cancer Center.