Dr. Robert I. Henkin is an endrocrinologist whose fascination in medical school with the mysteries of taste and smell has turned into a vocation.

His Georgetown university laboratory and clinic today deal with the little known afflictions of loss or impaired senses of taste and smell - conditions that affect 1 million to 2 million Americans.

Every year, 500 to 700 flock to Henkin's clinic to be treated for a variety of sensory aliments. He has a devoted band of followers made up of people he has helped regain their sense of taste or smell and others who see him as their only hope.

He also has detractors in the medical profession, some of whom regard his research as esoteric and others who question his ethics.

While his sometimes controversial research led to his departure from the national Insitute of Health in 1975, Henkin has gained a reputation as a uniquely qualified expert, a one-of-a-kind scientist.

He has become a consultant in a series of multimillion-dollar law suits involving chemical workers who have lost their senses of taste and smell.

He has also discovered a new protein in saliva, which he named gustin, and conducted research into a safe artificial sweetner at a time when saccharin, the last such item on the American market, faces a total ban.

Henkin has searched the Bible, unsuccessfully, for cases of lost taste and smell. He has discovered a reference in the medical literature of the 17th century to a dog suffering lost sense of smell and as a result of having its larynx removed. And he has noted that loss of the sense of smell was a key clue in 1973 Agatha Christie novel called "Poirot Loses a Client."

A major criticism leveled at Henkin by his professional colleagues is that he did not immediately publish the results of a study that discredited his own earlier work.

His first study, published in 1973, strongly implied that all loss of taste was due to low levels in the body of metals such as zinc and copper and that taste could be restored by raising those levels. The second study, with better controls, produced far less conclusive results.

Partly as a result of this dispute, Henkin says, he was forced out of NIH in 1975, and has continued his work at Georgetown. The second study was ultimately published in November, 1976.

Although apparently no one else is doing the same specific kind of research as Henkin, several neurologists and other physicians familiar with his published work say his methods seem sound and they have no reason to question his qualifications.

He works in a crowded basement office cluttered with file cabinets and carboard cartons. His laboratory and clinic are in a nearby building.

Henkin says about 40 per cent of his time is devoted to seeing patients, many of whom come from distant parts of the country, and 60 per cent is spent on research into the biochedical nature of taste and smell.

Loss of taste or smell or both, is most frequently caused by influenza, a sharp blow to the head, or a variety of metabolic diseases such as diabetes or hypothyroid, Henkin said.

Aside from loss of taste and smell, those afflicted also frequently suffer from depression, and in about 25 per cent of all cases, loss of libido, he said.

Not all of Henkin's patients are cured, but his success stories include Ruby Coniglio, a Closter, N.J., pizza maker whose tomatoes all smelled rotten to him until Henkin treated him with minuscule amounts of zinc sulfate, and an Englishwoman who is by appointment the supplier of nosegays to Queen Elizabeth.

The latter, Valerie Bennett-levy, had fractured her skull, and as a result everything she ate began to taste "absolutely rotten, really foul." After treatment, she said, her food tasted normal again.

In his work with patients and in the laboatory, Henkin says he has discovered links between taste loss and more serious conditions, including some kinds of cancer and anorexia nervosa, a disease in which young people radically curtail their eating and waste away.

Henkin is currently serving as a consultant for the Hooker Chemical and Plastic Corp. in a multimillion dollar law suit brought by workers who say they have lost their senses of taste and smell as a result of exposure to chlorine and related chemicals. According to sources close to the case, Henkin has found objective evidence of loss of taste in many of the workers he has examined.

As a spinoff of his research into the nature of taste, Henkin says he has isolated and purified a protein contained in an olive-seized red berry, which when combined with something sour, "produces the angelic taste of sucrose.

The shrub on which the berry grows is native to West Africa, Puerto Rico and Florida. It has been used as a sweetening agent for centuries by certain West African tribes, but Henkin says he has mastered the technology of limiting the sweet taste to moments rather than the hours it lasts in its natural state. He says he has been approached by companies interested in marketing the substance.

Perhaps the most important discovered related to the mechanism of taste yet made by Henkin is the isolation and purification of the protein he has named gustin. "Gust" comes from the Latin word for taste, and all proteins end in "in."

"Gustin," Henkin said, "causes taste buds to grow, develop and divide. It's like their blood. Wothout it, they will die."

Although much of the biochemistry of taste remains a mystery, even less is known about smell. "Smell is a whole other technology," Henkin said.

"The problem is," he continued, "that while it's easy to get saliva or biopsy taste buds, it is very difficult to get at the olfactory receptors, which are at the base of the skull."

Henkin said that he was beginning to get samples of the tissues that responds to odors, "but as little as is known about taste, less is known about smell."

Most of Henkin's clinical practice is devoted to helping patients regain their taste or smell, but ironically, he said that the most frequent question asked of him is, "Can you take away my taste so I won't eat so much?"

The answer is that he can, but he won't, because the cure could turn out to be worse than the disease.